Species Recorded | Taxon | Scientific Name | Common Name | Records | Latest |
| amphibian | Lissotriton helveticus | Palmate Newt | 773 | 2022 |
| amphibian | Lissotriton vulgaris | Smooth Newt | 1395 | 2022 |
| amphibian | Lissotriton vulgaris or Lissotriton helveticus | Smooth Newt or Palmate Newt | 37 | 2020 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lamprotatus annularis | a chalcid wasp | 1 | 1998 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum | a Lasioglossum solitary or mining bee (unidentified) | 11 | 2019 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum albipes | a solitary bee | 19 | 2020 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum calceatum | Common Furrow Bee | 78 | 2021 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum cupromicans | a solitary bee | 1 | 2005 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum fratellum | a solitary bee | 1 | 1998 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum fulvicorne | Chalk Furrow Bee | 13 | 2020 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum laevigatum | a solitary bee | 6 | 2019 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum lativentre | a solitary bee | 4 | 2004 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum leucopus | a solitary bee | 11 | 2020 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum leucozonium | a solitary bee | 28 | 2021 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum malachurum | a solitary bee | 9 | 2021 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum minutissimum | Least Mining Bee | 5 | 2018 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum morio | Brassy Mining Bee | 41 | 2021 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum parvulum | a solitary bee | 9 | 2019 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum pauxillum | a solitary bee | 15 | 2013 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum prasinum | a solitary bee | 2 | 1999 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum punctatissimum | a solitary bee | 1 | 2000 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum smeathmanellum | a solitary bee | 14 | 2020 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum villosulum | Shaggy Furrow Bee | 19 | 2021 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasioglossum zonulum | a solitary bee | 1 | 2000 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasius | a Lasius species (unidentified) | 3 | 2018 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasius alienus | an ant | 19 | 2005 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasius brunneus | Brown Ant | 13 | 2020 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasius flavus | Yellow Meadow Ant | 196 | 2021 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasius fuliginosus | Jet Ant | 12 | 2018 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasius mixtus | an ant | 2 | 1999 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lasius niger | Small Black Ant | 186 | 2022 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Leptocampoplex cremastoides | an insect - hymenopteran | 1 | 2008 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Leptothorax acervorum | Slender Ant | 1 | 2001 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lindenius albilabris | a solitary wasp | 3 | 2002 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Liposthenus latreillei | a gall wasp | 7 | 2020 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lissonota coracina | an insect - hymenopteran | 2 | 2003 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lissonota fundator | an insect - hymenopteran | 1 | 2002 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lissonota quadrinotata | an insect - hymenopteran | 1 | 1997 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lissonota semirufa | an insect - hymenopteran | 1 | 1995 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lissonota setosa | an insect - hymenopteran | 2 | 2011 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lissonota tenerrima | an insect - hymenopteran | 1 | 1997 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lonchidia clavicornis | a small parasitic wasp | 1 | 2003 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Lysiphlebus fabarum | an aphid parasitic wasp | 2 | 2003 |
| beetle | Laccobius | a Laccobius species (unidentified) | 35 | 2013 |
| beetle | Laccobius bipunctatus | a scavenger water beetle | 115 | 2013 |
| beetle | Laccobius colon | a scavenger water beetle | 27 | 2011 |
| beetle | Laccobius minutus | a scavenger water beetle | 47 | 2016 |
| beetle | Laccobius sinuatus | a scavenger water beetle | 3 | 2011 |
| beetle | Laccobius striatulus | a scavenger water beetle | 3 | 2013 |
| beetle | Laccophilus | a Laccophilus species (unidentified) | 5 | 2011 |
| beetle | Laccophilus hyalinus | a water beetle | 47 | 2013 |
| beetle | Laccophilus minutus | a water beetle | 82 | 2014 |
| beetle | Laemostenus terricola | a ground beetle | 7 | 2021 |
| beetle | Lagria hirta | a darkling beetle | 100 | 2021 |
| beetle | Lampyris noctiluca | Glow-worm | 263 | 2022 |
| beetle | Larinus planus | a weevil | 16 | 2020 |
| beetle | Lasiorhynchites cavifrons | a leafroller weevil | 2 | 1991 |
| beetle | Lathrobium brunnipes | a rove beetle | 11 | 2020 |
| beetle | Lathrobium fovulum | a rove beetle | 1 | 2014 |
| beetle | Lathrobium fulvipenne | a rove beetle | 9 | 2015 |
| beetle | Lathrobium impressum | a rove beetle | 1 | 2015 |
| beetle | Lathrobium quadratum | a rove beetle | 1 | 2004 |
| beetle | Latridius assimilis | a mould beetle | 4 | 2016 |
| beetle | Latridius minutus | a mould beetle | 4 | 2016 |
| beetle | Latridius porcatus | a latridius beetle | 1 | 2001 |
| beetle | Leiodes calcarata | a round fungus beetle | 3 | 2020 |
| beetle | Leiodes litura | a round fungus beetle | 4 | 2020 |
| beetle | Leiodes rugosa | a round fungus beetle | 1 | 2020 |
| beetle | Leiopus | a Leiopus species (unidentified) | 2 | 2017 |
| beetle | Leiopus nebulosus (sens. lat., pre 2009) | a longhorn beetle | 11 | 2019 |
| beetle | Leiosoma deflexum | a weevil | 19 | 2020 |
| beetle | Leistus ferrugineus | a ground beetle | 18 | 2021 |
| beetle | Leistus fulvibarbis | a ground beetle | 26 | 2021 |
| beetle | Leistus rufomarginatus | a ground beetle | 15 | 2021 |
| beetle | Leistus spinibarbis | a ground beetle | 12 | 2018 |
| beetle | Leistus terminatus | a ground beetle | 3 | 2020 |
| beetle | Lema cyanella | a leaf beetle | 4 | 2017 |
| beetle | Leptacinus pusillus | a rove beetle | 1 | 1998 |
| beetle | Leptinotarsa decemlineata | Colorado Beetle | 1 | 2004 |
| beetle | Leptinus testaceus | a nest beetle | 7 | 2021 |
| beetle | Leptura | a Leptura species (unidentified) | 1 | 2013 |
| beetle | Leptura quadrifasciata | a longhorn beetle | 3 | 2008 |
| beetle | Leptusa fumida | a rove beetle | 1 | 2001 |
| beetle | Leptusa ruficollis | a rove beetle | 1 | 2001 |
| beetle | Lesteva longoelytrata | a rove beetle | 5 | 2020 |
| beetle | Lesteva punctata | a rove beetle | 1 | 2014 |
| beetle | Lesteva sicula | an insect - beetle (Coleoptera) | 1 | 2016 |
| beetle | Lesteva sicula subsp. heeri | a rove beetle | 21 | 2021 |
| beetle | Licinus punctatulus | a ground beetle | 2 | 1987 |
| beetle | Lilioceris lilii | Lily Beetle | 93 | 2021 |
| beetle | Limnebius nitidus | a small water beetle | 3 | 2013 |
| beetle | Limnius | a Limnius species (unidentified) | 1 | 2012 |
| beetle | Limnius volckmari | a riffle beetle | 10 | 2000 |
| beetle | Limnobaris dolorosa | a weevil | 9 | 2021 |
| beetle | Limnobaris t-album | a weevil | 8 | 2021 |
| beetle | Limnoxenus niger | a scavenger water beetle | 2 | 1983 |
| beetle | Limobius borealis | a weevil | 3 | 1979 |
| beetle | Liophloeus tessulatus | a weevil | 25 | 2020 |
| beetle | Liopterus haemorrhoidalis | a water beetle | 25 | 2013 |
| beetle | Lissodema denticolle | a false weevil | 2 | 2017 |
| beetle | Litargus connexus | a hairy fungus beetle | 2 | 2020 |
| beetle | Lithocharis nigriceps | a rove beetle | 1 | 2015 |
| beetle | Lobrathium multipunctum | a rove beetle | 1 | 2002 |
| beetle | Lochmaea caprea | Willow Leaf Beetle | 12 | 2021 |
| beetle | Lochmaea crataegi | Hawthorn Leaf Beetle | 37 | 2019 |
| beetle | Lochmaea suturalis | Heather Beetle | 2 | 2017 |
| beetle | Longitarsus | a Longitarsus species (unidentified) | 2 | 2012 |
| beetle | Longitarsus anchusae | a leaf beetle | 4 | 2017 |
| beetle | Longitarsus atricillus | a leaf beetle | 1 | 2015 |
| beetle | Longitarsus dorsalis | a leaf beetle | 6 | 2019 |
| beetle | Longitarsus exoletus | a leaf beetle | 2 | 2001 |
| beetle | Longitarsus flavicornis | a leaf beetle | 10 | 2019 |
| beetle | Longitarsus gracilis | a leaf beetle | 3 | 2015 |
| beetle | Longitarsus jacobaeae | a leaf beetle | 4 | 2016 |
| beetle | Longitarsus kutscherae | a leaf beetle | 2 | 2016 |
| beetle | Longitarsus luridus | a leaf beetle | 8 | 2017 |
| beetle | Longitarsus melanocephalus | a leaf beetle | 15 | 2019 |
| beetle | Longitarsus membranaceus | a leaf beetle | 1 | 1999 |
| beetle | Longitarsus nigrofasciatus | a leaf beetle | 1 | 2016 |
| beetle | Longitarsus parvulus | Flax Flea Beetle | 16 | 2021 |
| beetle | Longitarsus pratensis | a leaf beetle | 2 | 2021 |
| beetle | Longitarsus succineus | Chrysanthemum Flea Beetle | 4 | 2003 |
| beetle | Longitarsus suturellus | a leaf beetle | 6 | 2020 |
| beetle | Lordithon lunulatus | a rove beetle | 4 | 2020 |
| beetle | Loricera pilicornis | a ground beetle | 52 | 2017 |
| beetle | Lucanus cervus | Stag Beetle | 2 | 1985 |
| beetle | Luperus longicornis | a leaf beetle | 8 | 2019 |
| beetle | Lycoperdina bovistae | a false ladybird | 4 | 2021 |
| beetle | Lyctus brunneus | Brown Powder-post Beetle | 1 | 1990 |
| beetle | Lythraria salicariae | Loosestrife Flea Beetle | 2 | 2000 |
| bird | Lanius collurio | Red-backed Shrike | 97 | 2021 |
| bird | Lanius excubitor | Great Grey Shrike | 61 | 2016 |
| bird | Lanius senator | Woodchat Shrike | 143 | 2017 |
| bird | Laridae | a gull or tern species (unidentified) | 82 | 2022 |
| bird | Larus | a gull (unidentified) | 1052 | 2022 |
| bird | Larus argentatus | Herring Gull | 26330 | 2023 |
| bird | Larus argentatus argentatus | Herring Gull ssp. argentatus | 12 | 2019 |
| bird | Larus cachinnans | Caspian Gull | 18 | 2019 |
| bird | Larus canus | Common Gull | 6815 | 2021 |
| bird | Larus delawarensis | Ring-billed Gull | 97 | 2019 |
| bird | Larus fuscus | Lesser Black-backed Gull | 23906 | 2023 |
| bird | Larus fuscus fuscus | Baltic Gull | 3 | 2017 |
| bird | Larus fuscus graellsii | British Lesser Black-backed Gull | 4 | 2016 |
| bird | Larus fuscus intermedius | Lesser Black-backed Gull intermedius | 59 | 2021 |
| bird | Larus fuscus x argentatus | Lesser Black-backed Gull x Herring Gull | 17 | 2019 |
| bird | Larus glaucoides | Iceland Gull | 114 | 2020 |
| bird | Larus glaucoides kumlieni | Kumlien's Iceland Gull | 7 | 2014 |
| bird | Larus hyperboreus | Glaucous Gull | 23 | 2021 |
| bird | Larus marinus | Great Black-backed Gull | 8003 | 2022 |
| bird | Larus michahellis | Yellow-legged Gull | 2268 | 2021 |
| bird | Larus smithsonianus | American herring Gull | 1 | 2017 |
| bird | Leucophaeus atricilla | Laughing Gull | 49 | 2020 |
| bird | Leucophaeus pipixcan | Franklin's Gull | 10 | 2008 |
| bird | Limnodromus scolopaceus | Long-billed Dowitcher | 11 | 2009 |
| bird | Limosa | a godwit (unidentified) | 5 | 2017 |
| bird | Limosa lapponica | Bar-tailed Godwit | 2069 | 2021 |
| bird | Limosa limosa | Black-tailed Godwit | 7229 | 2021 |
| bird | Limosa limosa islandica | Black-tailed Godwit (islandica) | 367 | 2020 |
| bird | Linaria cannabina | Linnet | 12695 | 2023 |
| bird | Linaria flavirostris | Twite | 141 | 2015 |
| bird | Locustella luscinioides | Savi's Warbler | 1 | 1986 |
| bird | Locustella naevia | Grasshopper Warbler | 2158 | 2023 |
| bird | Loxia curvirostra | Crossbill | 407 | 2022 |
| bird | Lullula arborea | Woodlark | 110 | 2021 |
| bird | Luscinia megarhynchos | Nightingale | 217 | 2021 |
| bird | Luscinia svecica | Bluethroat | 2 | 2010 |
| bird | Lymnocryptes minimus | Jack Snipe | 1807 | 2021 |
| booklouse or barklouse | Lepinotus patruelis | a booklouse or barklouse | 1 | 1980 |
| booklouse or barklouse | Loensia fasciata | a booklouse or barklouse | 2 | 2020 |
| booklouse or barklouse | Loensia variegata | a booklouse or barklouse | 2 | 2009 |
| bristletail (silverfish and allies) | Lepisma saccharina | Silver Fish | 8 | 2018 |
| bug | Lamproplax picea | a ground bug | 1 | 2014 |
| bug | Lamprotettix nitidulus | a leafhopper | 13 | 2021 |
| bug | Laodelphax striatella | a planthopper | 1 | 1995 |
| bug | Ledra aurita | a leafhopper | 12 | 2021 |
| bug | Legnotus limbosus | a shield bug | 22 | 2021 |
| bug | Leptoglossus occidentalis | Western Conifer Seed Bug | 14 | 2022 |
| bug | Leptopterna | a Leptopterna species (unidentified) | 4 | 2014 |
| bug | Leptopterna dolabrata | Meadow Plant Bug | 253 | 2022 |
| bug | Leptopterna ferrugata | a plantbug or grassbug | 10 | 2018 |
| bug | Lichtensia viburni | Viburnum Scale | 1 | 2015 |
| bug | Limnoporus rufoscutellatus | a pondskater | 1 | 1991 |
| bug | Limotettix striola | a leafhopper | 1 | 2009 |
| bug | Lindbergina aurovittata | a leafhopper | 2 | 2021 |
| bug | Linnavuoriana sexmaculata | a leafhopper | 1 | 2002 |
| bug | Liocoris tripustulatus | a plantbug or grassbug | 240 | 2022 |
| bug | Livia juncorum | a jumping plantlouse | 3 | 2003 |
| bug | Lopus decolor | a plantbug or grassbug | 3 | 2021 |
| bug | Loricula pselaphiformis | a minute bug | 1 | 2020 |
| bug | Lyctocoris (Lyctocoris) campestris | Debris Bug | 1 | 1900 |
| bug | Lygocoris | a Lygocoris species (unidentified) | 1 | 2016 |
| bug | Lygocoris (Lygocoris) pabulinus | Common Green Capsid | 95 | 2021 |
| bug | Lygocoris (Lygocoris) rugicollis | Apple Capsid | 3 | 2021 |
| bug | Lygus | a Lygus species (unidentified) | 2 | 2018 |
| bug | Lygus maritimus | a plantbug or grassbug | 5 | 2019 |
| bug | Lygus pratensis | a plantbug or grassbug | 10 | 2021 |
| bug | Lygus rugulipennis | European Tarnished Plant Bug | 26 | 2021 |
| bug | Lygus wagneri | a plantbug or grassbug | 2 | 2017 |
| caddis fly | Lepidostoma basale | a caddisfly | 3 | 2019 |
| caddis fly | Lepidostoma hirtum | a caddisfly | 3 | 2019 |
| caddis fly | Lepidostomatidae | a Lepidostomatidae caddisfly (unidentified) | 1 | 2003 |
| caddis fly | Leptoceridae | a Leptoceridae caddisfly (unidentified) | 27 | 2004 |
| caddis fly | Leptocerus tineiformis | a caddisfly | 4 | 2018 |
| caddis fly | Limnephilidae | a Limnephilidae caddisfly (unidentified) | 49 | 2018 |
| caddis fly | Limnephilus | a Limnephilus species (unidentified) | 22 | 2017 |
| caddis fly | Limnephilus affinis | a caddisfly | 11 | 2016 |
| caddis fly | Limnephilus auricula | a caddisfly | 21 | 2021 |
| caddis fly | Limnephilus decipiens | a caddisfly | 1 | 2013 |
| caddis fly | Limnephilus flavicornis | a caddisfly | 21 | 2021 |
| caddis fly | Limnephilus hirsutus | a caddisfly | 1 | 2013 |
| caddis fly | Limnephilus lunatus | a caddisfly | 85 | 2021 |
| caddis fly | Limnephilus marmoratus | a caddisfly | 49 | 2021 |
| caddis fly | Limnephilus rhombicus | a caddisfly | 5 | 2018 |
| caddis fly | Limnephilus sparsus | a caddisfly | 9 | 2021 |
| caddis fly | Limnephilus vittatus | a caddisfly | 8 | 2021 |
| caddis fly | Lype reducta | a caddisfly | 4 | 2018 |
| centipede | Lamyctes emarginatus | One-eyed centipede | 1 | 1994 |
| centipede | Lithobius | a Lithobius species (unidentified) | 7 | 2018 |
| centipede | Lithobius (Lithobius) borealis | a centipede | 1 | 1995 |
| centipede | Lithobius (Lithobius) calcaratus | a centipede | 1 | 2000 |
| centipede | Lithobius (Lithobius) forficatus | Common lithobius | 25 | 2020 |
| centipede | Lithobius (Lithobius) macilentus | a centipede | 1 | 1987 |
| centipede | Lithobius (Lithobius) melanops | a centipede | 3 | 2018 |
| centipede | Lithobius (Lithobius) variegatus | Variegated Centipede | 46 | 2019 |
| centipede | Lithobius (Monotarsobius) crassipes | Thick-legged lithobius | 1 | 2009 |
| centipede | Lithobius (Sigibius) microps | Least lithobius | 14 | 2011 |
| crustacean | Lepas (Anatifa) anatifera | Goose Barnacle | 2 | 2019 |
| crustacean | Lepas (Anatifa) hillii | a crustacean | 2 | 2019 |
| crustacean | Lernaeenicus sprattae | a crustacean | 2 | 1941 |
| crustacean | Lernaeocera lusci | a crustacean | 1 | 1938 |
| crustacean | Liocarcinus holsatus | Flying Crab | 2 | 1940 |
| dragonfly, hawker or damselfly | Lestes | a Lestes species (unidentified) | 3 | 2020 |
| dragonfly, hawker or damselfly | Lestes barbarus | Shy Emerald Damselfly | 1 | 2006 |
| dragonfly, hawker or damselfly | Lestes sponsa | Emerald Damselfly | 443 | 2021 |
| dragonfly, hawker or damselfly | Libellula | a Libellula species (unidentified) | 3 | 2012 |
| dragonfly, hawker or damselfly | Libellula depressa | Broad-bodied Chaser | 1357 | 2022 |
| dragonfly, hawker or damselfly | Libellula fulva | Scarce Chaser | 396 | 2021 |
| dragonfly, hawker or damselfly | Libellula quadrimaculata | Four-spotted Chaser | 293 | 2021 |
| dragonfly, hawker or damselfly | Libellulidae | a Libellulidae species (unidentified) | 7 | 2018 |
| earwig | Labia minor | Lesser Earwig | 15 | 2021 |
| fish | Labrus bergylta | Ballan Wrasse | 1 | 1879 |
| fish | Labrus mixtus | Cuckoo Wrasse | 1 | 1938 |
| fish | Lamna nasus | Porbeagle shark | 1 | 1871 |
| fish | Lampetra | a lamprey (unidentified) | 1 | 1993 |
| fish | Lampetra fluviatilis | River Lamprey | 2 | 1939 |
| fish | Lampetra planeri | Brook Lamprey | 5 | 2002 |
| fish | Lepidorhombus whiffiagonis | Sail Fluke | 2 | 1933 |
| fish | Leuciscus idus | Orfe | 2 | 2000 |
| fish | Leuciscus leuciscus | Dace | 37 | 2018 |
| fish | Leucoraja naevus | Cuckoo Ray | 2 | 1940 |
| fish | Limanda limanda | Dab | 2 | 1993 |
| fish | Liparis liparis | Sea Snail | 2 | 1940 |
| fish | Liza ramada | Thin-lipped Mullet | 2 | 2016 |
| fish | Lophius piscatorius | Angler Fish | 2 | 1908 |
| fish | Lota lota | Burbot | 3 | 1938 |
| fungus | Laccaria amethystina | a fungus | 41 | 2019 |
| fungus | Laccaria bicolor | a basidiomycete fungus | 1 | 1984 |
| fungus | Laccaria laccata | Amethyst Deceiver | 269 | 2021 |
| fungus | Laccaria pumila | a fungus | 1 | 2000 |
| fungus | Laccaria purpureobadia | a basidiomycete fungus | 6 | 2020 |
| fungus | Lachnella alboviolascens | a basidiomycete fungus | 1 | 2001 |
| fungus | Lachnella villosa | a basidiomycete fungus | 2 | 2008 |
| fungus | Lachnum aeruginellum | an ascomycete fungus | 1 | 1995 |
| fungus | Lachnum apalum | a fungus | 1 | 2008 |
| fungus | Lachnum brevipilosum (non Lachnum brevipilum (Höhn.) Nannf., 1932) | an ascomycete fungus | 5 | 2008 |
| fungus | Lachnum carneolum var. longisporum | a fungus | 2 | 2013 |
| fungus | Lachnum niveum | an ascomycete fungus | 12 | 2014 |
| fungus | Lachnum rhytismatis | an ascomycete fungus | 1 | 1997 |
| fungus | Lachnum virgineum | an ascomycete fungus | 8 | 2014 |
| fungus | Lacrymaria lacrymabunda | Weeping Widow | 58 | 2020 |
| fungus | Lactarius acerrimus | a russula or milk-cap | 23 | 2013 |
| fungus | Lactarius acris | a russula or milk-cap | 1 | 1994 |
| fungus | Lactarius aurantiacus | a russula or milk-cap | 9 | 2012 |
| fungus | Lactarius azonites | a russula or milk-cap | 7 | 2000 |
| fungus | Lactarius blennius | Slimy Milk-cap | 23 | 2013 |
| fungus | Lactarius camphoratus | Curry-scented Milk-cap | 7 | 2014 |
| fungus | Lactarius chrysorrheus | a russula or milk-cap | 7 | 2005 |
| fungus | Lactarius circellatus | a russula or milk-cap | 5 | 1997 |
| fungus | Lactarius citriolens | a russula or milk-cap | 1 | 2009 |
| fungus | Lactarius controversus | a russula or milk-cap | 4 | 2014 |
| fungus | Lactarius cyathula | a russula or milk-cap | 3 | 1998 |
| fungus | Lactarius decipiens | a russula or milk-cap | 2 | 2005 |
| fungus | Lactarius deliciosus | Saffron Milk-cap | 2 | 2004 |
| fungus | Lactarius deterrimus | a russula or milk-cap | 28 | 2015 |
| fungus | Lactarius fluens | a russula or milk-cap | 2 | 2012 |
| fungus | Lactarius fuliginosus | a russula or milk-cap | 1 | 1997 |
| fungus | Lactarius fulvissimus | a russula or milk-cap | 51 | 2014 |
| fungus | Lactarius glyciosmus | Coconut-scented Milk-cap | 20 | 2018 |
| fungus | Lactarius hepaticus | a russula or milk-cap | 2 | 2010 |
| fungus | Lactarius lacunarum | a russula or milk-cap | 8 | 2003 |
| fungus | Lactarius mairei | a russula or milk-cap | 3 | 2010 |
| fungus | Lactarius obscuratus | a russula or milk-cap | 13 | 2020 |
| fungus | Lactarius omphaliiformis | a fungus | 1 | 2003 |
| fungus | Lactarius pallidus | a russula or milk-cap | 4 | 2011 |
| fungus | Lactarius plumbeus | a fungus | 1 | 1970 |
| fungus | Lactarius pterosporus | a fungus | 2 | 2002 |
| fungus | Lactarius pubescens | a russula or milk-cap | 11 | 2017 |
| fungus | Lactarius pyrogalus | Fiery Milkcap | 23 | 2014 |
| fungus | Lactarius quietus | Oak Milk-cap | 66 | 2013 |
| fungus | Lactarius romagnesii | a fungus | 1 | 2013 |
| fungus | Lactarius rufus | Rufous Milk-cap | 3 | 2010 |
| fungus | Lactarius semisanguifluus | a russula or milk-cap | 49 | 2015 |
| fungus | Lactarius serifluus | a russula or milk-cap | 1 | 2010 |
| fungus | Lactarius spinosulus | a russula or milk-cap | 1 | 1998 |
| fungus | Lactarius stephensii | a fungus | 1 | 1959 |
| fungus | Lactarius subdulcis | a russula or milk-cap | 62 | 2014 |
| fungus | Lactarius subumbonatus | a fungus | 9 | 2014 |
| fungus | Lactarius tabidus | a russula or milk-cap | 48 | 2018 |
| fungus | Lactarius theiogalus | a russula or milk-cap | 1 | 2005 |
| fungus | Lactarius torminosus | Woolly Milk-cap | 15 | 2010 |
| fungus | Lactarius turpis | Ugly Milk-cap | 10 | 2010 |
| fungus | Lactarius uvidus | a russula or milk-cap | 9 | 2007 |
| fungus | Lactarius vellereus | Fleecy Milk-cap | 2 | 2002 |
| fungus | Lactarius vietus | Grey Milk-cap | 3 | 2010 |
| fungus | Lactarius volemus | a russula or milk-cap | 1 | 1995 |
| fungus | Lactarius zonarius | a russula or milk-cap | 33 | 2009 |
| fungus | Laetiporus sulphureus | Chicken of the Woods | 94 | 2018 |
| fungus | Lanzia echinophila | an ascomycete fungus | 1 | 2008 |
| fungus | Lasiosphaeria ovina | an ascomycete fungus | 2 | 1998 |
| fungus | Lecanora achariana | a fungus | 1 | 2005 |
| fungus | Leccinum | a fungus | 1 | 2009 |
| fungus | Leccinum aerugineum | a fungus | 10 | 2009 |
| fungus | Leccinum aurantiacum | a bolete | 2 | 2005 |
| fungus | Leccinum holopus | a bolete | 2 | 2002 |
| fungus | Leccinum pseudoscabrum | a bolete | 2 | 1994 |
| fungus | Leccinum scabrum | Brown Birch-bolete | 39 | 2019 |
| fungus | Leccinum variicolor | a bolete | 11 | 2010 |
| fungus | Leccinum versipelle | Orange Birch-bolete | 1 | 2002 |
| fungus | Lentinellus cochleatus | a basidiomycete fungus | 4 | 2013 |
| fungus | Lentinus brumalis | a basidiomycete fungus | 26 | 2014 |
| fungus | Lentinus tigrinus | a basidiomycete fungus | 1 | 2007 |
| fungus | Lentomitella cirrhosa | an ascomycete fungus | 1 | 2005 |
| fungus | Lenzites betulina | a basidiomycete fungus | 9 | 2013 |
| fungus | Leotia lubrica | Jelly Baby Fungus | 15 | 2019 |
| fungus | Lepiota | a Lepiota species (unidentified) | 1 | 1982 |
| fungus | Lepiota boudieri | an agaric | 33 | 2014 |
| fungus | Lepiota brunneoincarnata | an agaric | 1 | 1997 |
| fungus | Lepiota castanea | an agaric | 27 | 2020 |
| fungus | Lepiota cingulum | a fungus | 1 | 2008 |
| fungus | Lepiota clypeolaria | an agaric | 2 | 1999 |
| fungus | Lepiota cristata | Stinking Parasol | 161 | 2014 |
| fungus | Lepiota echinella | a fungus | 2 | 2008 |
| fungus | Lepiota echinella var. echinella | an agaric | 14 | 2010 |
| fungus | Lepiota eriophora | an agaric | 2 | 1999 |
| fungus | Lepiota felina | an agaric | 8 | 2002 |
| fungus | Lepiota forquignonii | an agaric | 1 | 2002 |
| fungus | Lepiota fuscovinacea | an agaric | 1 | 2005 |
| fungus | Lepiota grangei | an agaric | 4 | 2015 |
| fungus | Lepiota griseovirens | an agaric | 4 | 2012 |
| fungus | Lepiota ignivolvata | an agaric | 1 | 1999 |
| fungus | Lepiota magnispora | an agaric | 5 | 2020 |
| fungus | Lepiota obscura | a fungus | 3 | 2000 |
| fungus | Lepiota ochraceofulva | an agaric | 9 | 2009 |
| fungus | Lepiota oreadiformis | an agaric | 61 | 2020 |
| fungus | Lepiota pseudolilacea | an agaric | 33 | 2013 |
| fungus | Lepiota subalba | an agaric | 3 | 2006 |
| fungus | Lepiota subgracilis | an agaric | 4 | 1997 |
| fungus | Lepiota subincarnata | an agaric | 33 | 2012 |
| fungus | Lepiota sublaevigata | a fungus | 1 | 1996 |
| fungus | Lepiota tomentella | an agaric | 13 | 2004 |
| fungus | Lepiota xanthophylla | an agaric | 4 | 2004 |
| fungus | Lepista | a Lepista species (unidentified) | 1 | 2017 |
| fungus | Lepista flaccida | Tawny Funnel | 153 | 2022 |
| fungus | Lepista luscina | a basidiomycete fungus | 3 | 2000 |
| fungus | Lepista nuda | Wood Blewit | 205 | 2020 |
| fungus | Lepista panaeolus | a fungus | 28 | 2015 |
| fungus | Lepista saeva | Field Blewit | 30 | 2021 |
| fungus | Lepista sordida | a basidiomycete fungus | 33 | 2020 |
| fungus | Leptosphaeria acuta | a fungus | 47 | 2013 |
| fungus | Leptosphaeria doliolum | a fungus | 6 | 1997 |
| fungus | Leptospora rubella | a fungus | 1 | 1997 |
| fungus | Leptosporomyces mutabilis | a basidiomycete fungus | 2 | 2000 |
| fungus | Leptostroma eupatorii | a fungus | 2 | 2010 |
| fungus | Leratiomyces ceres | Redlead Roundhead | 3 | 2021 |
| fungus | Leratiomyces squamosus var. squamosus | an agaric | 1 | 1997 |
| fungus | Leucoagaricus badhamii | an agaric | 6 | 2020 |
| fungus | Leucoagaricus brunneocingulatus | an agaric | 1 | 1995 |
| fungus | Leucoagaricus crystallifer | a fungus | 2 | 2013 |
| fungus | Leucoagaricus leucothites | an agaric | 29 | 2006 |
| fungus | Leucoagaricus nympharum | an agaric | 2 | 1996 |
| fungus | Leucoagaricus pilatianus | an agaric | 2 | 2005 |
| fungus | Leucoagaricus serenus | an agaric | 10 | 2020 |
| fungus | Leucoagaricus sericifer | an agaric | 2 | 2014 |
| fungus | Leucocoprinus brebissonii | an agaric | 16 | 2020 |
| fungus | Leucocoprinus cepistipes | an agaric | 1 | 1999 |
| fungus | Leucopaxillus giganteus | Giant Funnel-cap | 2 | 2000 |
| fungus | Leveillula verbasci | a conidial powdery mildew | 4 | 2008 |
| fungus | Lichenoconium xanthoriae | a fungus | 1 | 2020 |
| fungus | Lichenomphalia velutina | a basidiomycete fungus | 1 | 1995 |
| fungus | Lichina confinis | an ascomycete fungus | 1 | 1991 |
| fungus | Limacella delicata | a fungus | 1 | 2006 |
| fungus | Limacella delicata var. delicata | a basidiomycete fungus | 3 | 2006 |
| fungus | Limacella delicata var. glioderma | a basidiomycete fungus | 4 | 1999 |
| fungus | Limacella delicata var. vinosorubescens | a fungus | 13 | 2008 |
| fungus | Limacella ochraceolutea | a basidiomycete fungus | 16 | 2004 |
| fungus | Litschauerella clematidis | a basidiomycete fungus | 3 | 2010 |
| fungus | Lopadostoma turgidum | an ascomycete fungus | 1 | 2005 |
| fungus | Lycoperdon dermoxanthum | Dwarf Bovist | 5 | 1985 |
| fungus | Lycoperdon echinatum | Hedgehog Puffball | 23 | 2013 |
| fungus | Lycoperdon excipuliforme | Pestle-Shaped Puffball | 90 | 2019 |
| fungus | Lycoperdon lividum | Grassland Puffball | 34 | 2017 |
| fungus | Lycoperdon mammiforme | Flaky Puffball | 12 | 2013 |
| fungus | Lycoperdon molle | Soft-Spined Puffball | 7 | 2018 |
| fungus | Lycoperdon nigrescens | Blackish Puffball | 40 | 2013 |
| fungus | Lycoperdon (non Pers.) | a lycoperdon puffball or earth star (unidentified) | 8 | 2019 |
| fungus | Lycoperdon perlatum | Puffball | 217 | 2019 |
| fungus | Lycoperdon pratense | Meadow Puffball | 185 | 2016 |
| fungus | Lycoperdon pyriforme | Stump Puffball | 200 | 2021 |
| fungus | Lycoperdon umbrinum | Umber-brown Puffball | 4 | 2003 |
| fungus | Lycoperdon utriforme | Mosaic Puffball | 9 | 2020 |
| fungus | Lyophyllum | a Lyophyllum species (unidentified) | 1 | 2000 |
| fungus | Lyophyllum connatum | a basidiomycete fungus | 3 | 2013 |
| fungus | Lyophyllum crassifolium | a fungus | 12 | 2001 |
| fungus | Lyophyllum decastes | a basidiomycete fungus | 29 | 2020 |
| fungus | Lyophyllum eustygium | a fungus | 8 | 2013 |
| fungus | Lyophyllum immundum | a basidiomycete fungus | 4 | 1996 |
| fungus | Lyophyllum loricatum | a basidiomycete fungus | 6 | 2004 |
| grasshopper, cricket or true cricket | Leptophyes | a Leptophyes species (unidentified) | 1 | 2009 |
| grasshopper, cricket or true cricket | Leptophyes punctatissima | Speckled Bush Cricket | 630 | 2022 |
| harvestman | Leiobunum | a Leiobunum species (unidentified) | 1 | 2014 |
| harvestman | Leiobunum blackwalli | a harvestman | 19 | 2020 |
| harvestman | Leiobunum rotundum | a harvestman | 52 | 2019 |
| harvestman | Lophopilio palpinalis | a harvestman | 10 | 2010 |
| insect - true fly (Diptera) | Leptosciarella cerifera | an insect - true fly (Diptera) | 1 | 2003 |
| insect - true fly (Diptera) | Leptosciarella fuscipalpa | an insect - true fly (Diptera) | 2 | 2021 |
| leech, flatworm or ribbon worm | Lineus ruber | a ribbon worm (Nemertinea) | 6 | 1976 |
| lichen | Lecanactis abietina | a lichen | 10 | 2016 |
| lichen | Lecania atrynoides | a lichen | 1 | 1991 |
| lichen | Lecania cuprea | a lichen | 2 | 2018 |
| lichen | Lecania cyrtella | a lichen | 7 | 2014 |
| lichen | Lecania erysibe s. lat. | a lichen | 12 | 2008 |
| lichen | Lecania inundata | a lichen | 1 | 2014 |
| lichen | Lecania naegelii | a lichen | 4 | 2016 |
| lichen | Lecania rabenhorstii | a lichen | 2 | 2010 |
| lichen | Lecania turicensis | a lichen | 1 | 2010 |
| lichen | Lecanographa lyncea | a lichen | 1 | 1996 |
| lichen | Lecanora albella | a lichen | 7 | 2010 |
| lichen | Lecanora albellula | a lichen | 1 | 2017 |
| lichen | Lecanora argentata | a lichen | 1 | 2014 |
| lichen | Lecanora campestris | a lichen | 3 | 2020 |
| lichen | Lecanora campestris subsp. campestris | a lichen | 23 | 2014 |
| lichen | Lecanora carpinea | a lichen | 7 | 2020 |
| lichen | Lecanora chlarotera | a lichen | 68 | 2020 |
| lichen | Lecanora compallens | a lichen | 4 | 2010 |
| lichen | Lecanora conferta | a lichen | 2 | 2011 |
| lichen | Lecanora confusa | a lichen | 8 | 2016 |
| lichen | Lecanora conizaeoides | a lichen | 4 | 2020 |
| lichen | Lecanora conizaeoides f. conizaeoides | a lichen | 9 | 2010 |
| lichen | Lecanora expallens | a lichen | 28 | 2014 |
| lichen | Lecanora gangaleoides | a lichen | 2 | 1998 |
| lichen | Lecanora helicopis | a lichen | 1 | 1991 |
| lichen | Lecanora horiza | a lichen | 1 | 2017 |
| lichen | Lecanora intricata | a lichen | 5 | 2004 |
| lichen | Lecanora muralis (sensu auct.) | a lichen | 21 | 2020 |
| lichen | Lecanora orosthea | a lichen | 3 | 2011 |
| lichen | Lecanora polytropa | a lichen | 7 | 2020 |
| lichen | Lecanora pulicaris | a lichen | 2 | 2011 |
| lichen | Lecanora rugosella | a lichen | 1 | 1996 |
| lichen | Lecanora rupicola var. rupicola | a lichen | 2 | 2011 |
| lichen | Lecanora saligna | a lichen | 1 | 1991 |
| lichen | Lecanora soralifera | a lichen | 1 | 1985 |
| lichen | Lecanora sulphurea | a lichen | 2 | 2008 |
| lichen | Lecanora symmicta | a lichen | 10 | 2011 |
| lichen | Lecanora varia | a lichen | 3 | 2020 |
| lichen | Lecidea fuscoatra s. lat. | a lichen | 2 | 2011 |
| lichen | Lecidea lithophila | a lichen | 1 | 2009 |
| lichen | Lecidella | a Lecidella species (unidentified) | 1 | 2013 |
| lichen | Lecidella asema | a lichen | 2 | 2004 |
| lichen | Lecidella carpathica | a lichen | 1 | 2012 |
| lichen | Lecidella elaeochroma | a lichen | 24 | 2020 |
| lichen | Lecidella elaeochroma f. elaeochroma | a lichen | 45 | 2016 |
| lichen | Lecidella scabra | a lichen | 19 | 2020 |
| lichen | Lecidella stigmatea | a lichen | 23 | 2020 |
| lichen | Lepraria | a Lepraria lichen (unidentified) | 5 | 2014 |
| lichen | Lepraria chrysodeta | a lichen | 1 | 1985 |
| lichen | Lepraria finkii | a lichen | 13 | 2020 |
| lichen | Lepraria incana s. lat. | a lichen | 31 | 2017 |
| lichen | Lepraria membranacea | a lichen | 1 | 1985 |
| lichen | Lepraria nivalis | a lichen | 4 | 2018 |
| lichen | Lepraria vouauxii | a lichen | 1 | 2002 |
| lichen | Leptogium | a Leptogium species (unidentified) | 2 | 2018 |
| lichen | Leptogium cochleatum | a lichen | 1 | 1975 |
| lichen | Leptogium diffractum | a lichen | 1 | 1988 |
| lichen | Leptogium gelatinosum | a lichen | 10 | 2020 |
| lichen | Leptogium massiliense | a lichen | 2 | 2016 |
| lichen | Leptogium plicatile | a lichen | 4 | 2016 |
| lichen | Leptogium schraderi | a lichen | 6 | 2018 |
| lichen | Leptogium teretiusculum | a lichen | 1 | 1988 |
| lichen | Leptogium turgidum | a lichen | 4 | 2018 |
| lichen | Lichen (unidentified) | a Lichen species (unidentified) | 9 | 2018 |
| lichen | Lobaria pulmonaria | a lichen | 1 | 2013 |
| liverwort | Leiocolea badensis | Scarce Notchwort | 2 | 1990 |
| liverwort | Leiocolea turbinata | Top Notchwort | 10 | 2020 |
| liverwort | Lejeunea cavifolia | Micheli's Least Pouncewort | 10 | 2021 |
| liverwort | Lejeunea lamacerina | Western Pouncewort | 3 | 1998 |
| liverwort | Lepidozia reptans | Creeping Fingerwort | 13 | 2021 |
| liverwort | Lophocolea bidentata | Bifid Crestwort | 86 | 2021 |
| liverwort | Lophocolea heterophylla | Variable-leaved Crestwort | 48 | 2021 |
| liverwort | Lophozia ventricosa | Tumid Notchwort | 1 | 1991 |
| liverwort | Lunularia | a Lunularia species (unidentified) | 1 | 1940 |
| liverwort | Lunularia cruciata | Crescent-cup Liverwort | 39 | 2021 |
| mammal | Lepus europaeus | Brown Hare | 1174 | 2023 |
| mammal | Lutra lutra | Otter | 3706 | 2022 |
| mammal - marine | Lagenorhynchus albirostris | White-beaked Dolphin | 1 | 1936 |
| mayfly | Leptophlebiidae | a Leptophlebiidae mayfly (unidentified) | 4 | 2000 |
| mollusc | Lacuna pallidula | Pallid Chink Shell | 2 | 1986 |
| mollusc | Lasaea adansoni | a non-marine mollusc | 1 | 1912 |
| mollusc | Lauria (Lauria) cylindracea | Chrysalis Snail | 29 | 2016 |
| mollusc | Lehmannia marginata | Tree Slug | 27 | 2019 |
| mollusc | Lepidochitona (Lepidochitona) cinerea | Grey Chiton | 6 | 1976 |
| mollusc | Limacus flavus | Yellow Slug | 9 | 2021 |
| mollusc | Limacus maculatus | Irish Yellow Slug | 15 | 2021 |
| mollusc | Limapontia depressa | a mollusc | 1 | 1971 |
| mollusc | Limax | a Limax keelback slug (unidentified) | 2 | 2008 |
| mollusc | Limax cinereoniger | Ash-grey Slug | 5 | 1998 |
| mollusc | Limax flavus agg. | a mollusc | 1 | 2007 |
| mollusc | Limax maximus | Great Grey Slug | 49 | 2022 |
| mollusc | Limecola balthica | Baltic Tellin | 27 | 2019 |
| mollusc | Limnaeidae | a Limnaeidae species (unidentified) | 1 | 1988 |
| mollusc | Littorina fabalis | a mollusc | 1 | 1995 |
| mollusc | Littorina littorea | Common Periwinkle | 14 | 2019 |
| mollusc | Littorina obtusata | Flat Periwinkle | 25 | 1976 |
| mollusc | Littorina saxatilis/arcana | Rough Periwinkle | 17 | 2015 |
| mollusc | Loligo forbesii | Common Squid | 1 | 1938 |
| mollusc | Lutraria lutraria | Common Otter Shell | 1 | 1937 |
| mollusc | Lymnaea | a Lymnaea species (unidentified) | 7 | 2019 |
| mollusc | Lymnaea stagnalis | Great Pond Snail | 304 | 2021 |
| mollusc | Lymnaea (Stagnicola) | a mollusc | 1 | 2017 |
| mollusc | Lymnaeidae | a Lymnaeidae pond snail (unidentified) | 46 | 2021 |
| moss | Leptobryum pyriforme | Golden Thread-moss | 3 | 2020 |
| moss | Leptodictyum riparium | Kneiff's Feather-moss | 14 | 2021 |
| moss | Leptodontium flexifolium | Bent-leaved Beard-moss | 1 | 1990 |
| moss | Leskea polycarpa | Many-fruited Leskea | 1 | 2016 |
| moss | Leucobryum glaucum | Large White-moss | 1 | 2000 |
| moss | Leucobryum juniperoideum | Smaller White-moss | 3 | 2019 |
| moss | Loeskeobryum brevirostre | Short-beaked Wood-moss | 6 | 2017 |
| moth or butterfly - butterfly | Lasiommata megera | Wall | 1238 | 2021 |
| moth or butterfly - butterfly | Limenitis camilla | White Admiral | 297 | 2021 |
| moth or butterfly - butterfly | Lycaena phlaeas | Small Copper | 4426 | 2022 |
| moth or butterfly - butterfly | Lycaena phlaeas eleus | a small copper | 398 | 2007 |
| moth or butterfly - butterfly | Lycaenidae | a blue or a copper or a hairstreak butterfly (unidentified) | 11 | 2013 |
| moth or butterfly - butterfly | Lycaenidae sp. (a blue butterfly unidentified) | a blue butterfly (unidentified) | 74 | 2022 |
| moth or butterfly - macro moth | Lacanobia contigua | Beautiful Brocade | 2 | 1993 |
| moth or butterfly - macro moth | Lacanobia oleracea | Bright-line Brown-eye | 3702 | 2022 |
| moth or butterfly - macro moth | Lacanobia suasa | Dog's Tooth | 54 | 2021 |
| moth or butterfly - macro moth | Lacanobia thalassina | Pale-shouldered Brocade | 60 | 2018 |
| moth or butterfly - macro moth | Lacanobia w-latinum | Light Brocade | 136 | 2022 |
| moth or butterfly - macro moth | Lampropteryx otregiata | Devon Carpet | 3 | 2019 |
| moth or butterfly - macro moth | Lampropteryx suffumata | Water Carpet | 143 | 2022 |
| moth or butterfly - macro moth | Laothoe populi | Poplar Hawk-moth | 1128 | 2022 |
| moth or butterfly - macro moth | Larentia clavaria | Mallow | 31 | 2022 |
| moth or butterfly - macro moth | Lasiocampa quercus | Oak Eggar | 224 | 2022 |
| moth or butterfly - macro moth | Lasiocampa trifolii | Grass Eggar | 1 | 1949 |
| moth or butterfly - macro moth | Laspeyria flexula | Beautiful Hook-tip | 578 | 2022 |
| moth or butterfly - macro moth | Lateroligia ophiogramma | Double Lobed | 64 | 2021 |
| moth or butterfly - macro moth | Lenisa geminipuncta | Twin-spotted Wainscot | 18 | 2022 |
| moth or butterfly - macro moth | Lepidoptera | a butterfly or moth (unidentified) | 178 | 2019 |
| moth or butterfly - macro moth | Leucania comma | Shoulder-striped Wainscot | 501 | 2022 |
| moth or butterfly - macro moth | Leucania loreyi | Cosmopolitan | 2 | 2006 |
| moth or butterfly - macro moth | Leucania obsoleta | Obscure Wainscot | 70 | 2021 |
| moth or butterfly - macro moth | Leucania putrescens | Devonshire Wainscot | 2 | 1960 |
| moth or butterfly - macro moth | Leucoma salicis | White Satin Moth | 26 | 2020 |
| moth or butterfly - macro moth | Ligdia adustata | Scorched Carpet | 674 | 2022 |
| moth or butterfly - macro moth | Lithophane leautieri | a moth | 65 | 2022 |
| moth or butterfly - macro moth | Lithophane leautieri hesperica | Blair's Shoulder-knot | 787 | 2022 |
| moth or butterfly - macro moth | Lithophane ornitopus | Grey Shoulder-knot | 175 | 2022 |
| moth or butterfly - macro moth | Lithophane ornitopus lactipennis | a moth | 5 | 2004 |
| moth or butterfly - macro moth | Lithophane semibrunnea | Tawny Pinion | 52 | 2022 |
| moth or butterfly - macro moth | Lithophane socia | Pale Pinion | 159 | 2022 |
| moth or butterfly - macro moth | Lithosia quadra | Four-spotted Footman | 44 | 2022 |
| moth or butterfly - macro moth | Litoligia literosa | Rosy Minor | 164 | 2022 |
| moth or butterfly - macro moth | Lobophora halterata | Seraphim | 87 | 2022 |
| moth or butterfly - macro moth | Lomaspilis marginata | Clouded Border | 749 | 2022 |
| moth or butterfly - macro moth | Lomographa bimaculata | White-pinion Spotted | 235 | 2019 |
| moth or butterfly - macro moth | Lomographa temerata | Clouded Silver | 1198 | 2022 |
| moth or butterfly - macro moth | Luperina testacea | Flounced Rustic | 2049 | 2022 |
| moth or butterfly - macro moth | Lycia hirtaria | Brindled Beauty | 654 | 2022 |
| moth or butterfly - macro moth | Lycophotia porphyrea | True Lover's Knot | 96 | 2022 |
| moth or butterfly - macro moth | Lygephila pastinum | Blackneck | 119 | 2021 |
| moth or butterfly - macro moth | Lymantria monacha | Black Arches | 339 | 2022 |
| moth or butterfly - micro moth | Lampronia capitella | Currant Shoot Borer | 2 | 2008 |
| moth or butterfly - micro moth | Lampronia corticella | Raspberry Moth | 4 | 2014 |
| moth or butterfly - micro moth | Lampronia fuscatella | a longhorn moth | 2 | 2021 |
| moth or butterfly - micro moth | Lampronia luzella | a longhorn moth | 2 | 1908 |
| moth or butterfly - micro moth | Lampronia morosa | a longhorn moth | 4 | 2017 |
| moth or butterfly - micro moth | Lathronympha strigana | Red Piercer | 73 | 2020 |
| moth or butterfly - micro moth | Leucoptera laburnella | Laburnum Leaf Miner | 19 | 2020 |
| moth or butterfly - micro moth | Leucoptera laburnella form wailesella | a micro-moth | 2 | 2001 |
| moth or butterfly - micro moth | Leucoptera malifoliella | Pear Leaf Blister Moth | 5 | 2022 |
| moth or butterfly - micro moth | Leucoptera spartifoliella | a micro-moth | 3 | 2016 |
| moth or butterfly - micro moth | Leucospilapteryx omissella | a micro-moth | 1 | 2001 |
| moth or butterfly - micro moth | Limnaecia phragmitella | a micro-moth | 104 | 2022 |
| moth or butterfly - micro moth | Lobesia abscisana | Smoky-barred Marble | 245 | 2022 |
| moth or butterfly - micro moth | Lobesia littoralis | a tortrix moth | 41 | 2021 |
| moth or butterfly - micro moth | Lobesia reliquana | a tortrix moth | 9 | 2011 |
| moth or butterfly - micro moth | Lozotaenia forsterana | a tortrix moth | 118 | 2021 |
| moth or butterfly - micro moth | Lozotaeniodes formosana | a tortrix moth | 114 | 2022 |
| moth or butterfly - micro moth | Luffia ferchaultella | a bagworm moth | 14 | 2021 |
| moth or butterfly - micro moth | Lyonetia clerkella | Apple Leaf Miner | 465 | 2022 |
| plant | Laburnum | a laburnum (unidentified) | 8 | 2017 |
| plant | Laburnum anagyroides | Laburnum | 157 | 2020 |
| plant | Lactuca saligna | Least Lettuce | 2 | 1928 |
| plant | Lactuca serriola | Prickly Lettuce | 1048 | 2021 |
| plant | Lactuca serriola subsp. integrifolia | a flowering plant | 10 | 2011 |
| plant | Lactuca serriola subsp. serriola | a flowering plant | 8 | 2016 |
| plant | Lactuca tatarica | Blue Lettuce | 4 | 2013 |
| plant | Lactuca virosa | Great Lettuce | 94 | 2020 |
| plant | Lagarosiphon major | Curly Waterweed | 24 | 2018 |
| plant | Lagurus ovatus | Hare's-tail | 9 | 2019 |
| plant | Lamiastrum galeobdolon | Yellow Archangel | 528 | 2021 |
| plant | Lamiastrum galeobdolon montanum montanum | a flowering plant | 1 | 1998 |
| plant | Lamiastrum galeobdolon subsp. argentatum | Variegated Yellow Archangel | 149 | 2020 |
| plant | Lamiastrum galeobdolon subsp. galeobdolon | a yellow archangel | 8 | 2020 |
| plant | Lamiastrum galeobdolon subsp. montanum | a yellow archangel | 1020 | 2016 |
| plant | Lamium | a dead-nettle (unidentified) | 13 | 2021 |
| plant | Lamium album | White Dead-nettle | 4076 | 2022 |
| plant | Lamium amplexicaule | Hen-bit Dead-nettle | 123 | 2015 |
| plant | Lamium confertum | Northern Dead-nettle | 2 | 1922 |
| plant | Lamium hybridum | Cut-leaved Dead-nettle | 30 | 2020 |
| plant | Lamium maculatum | Spotted Dead-nettle | 33 | 2019 |
| plant | Lamium orvala | a flowering plant | 1 | 2019 |
| plant | Lamium purpureum | Red Dead-nettle | 2855 | 2022 |
| plant | Lamprocapnos | a Lamprocapnos species (unidentified) | 1 | 2013 |
| plant | Lappula squarrosa | Bur Forget-me-not | 7 | 2003 |
| plant | Lapsana communis | Nipplewort | 3501 | 2021 |
| plant | Lapsana communis subsp. communis | a nipplewort | 5 | 2004 |
| plant | Larix | a larch (unidentified) | 40 | 2018 |
| plant | Larix decidua | Larch | 375 | 2021 |
| plant | Larix decidua pendula | Weeping European Larch | 1 | 2011 |
| plant | Larix decidua x kaempferi = L. x marschlinsii | Hybrid Larch | 33 | 2019 |
| plant | Larix kaempferi | Japanese Larch | 16 | 2016 |
| plant | Larix laricina | American Larch | 2 | 1984 |
| plant | Lathraea clandestina | Purple Toothwort | 20 | 2022 |
| plant | Lathraea squamaria | Toothwort | 271 | 2019 |
| plant | Lathyrus | a Lathyrus pea (unidentified) | 10 | 2013 |
| plant | Lathyrus annuus | Fodder Pea | 4 | 1959 |
| plant | Lathyrus aphaca | Yellow Vetchling | 16 | 2017 |
| plant | Lathyrus cicera | a flowering plant | 2 | 2014 |
| plant | Lathyrus clymenum | a flowering plant | 2 | 1930 |
| plant | Lathyrus grandiflorus | Two-flowered Everlasting-pea | 5 | 1987 |
| plant | Lathyrus hierosolymitanus | a flowering plant | 1 | 1937 |
| plant | Lathyrus inconspicuus | a flowering plant | 2 | 1940 |
| plant | Lathyrus latifolius | Broad-leaved Everlasting-pea | 164 | 2021 |
| plant | Lathyrus linifolius | Bitter-vetch | 151 | 2022 |
| plant | Lathyrus linifolius var. tenuifolius | a flowering plant | 1 | 2006 |
| plant | Lathyrus nissolia | Grass Vetchling | 420 | 2022 |
| plant | Lathyrus odoratus | Sweet Pea | 4 | 2019 |
| plant | Lathyrus pratensis | Meadow Vetchling | 4620 | 2022 |
| plant | Lathyrus sativus | Indian Pea | 2 | 2017 |
| plant | Lathyrus sylvestris | Narrow-leaved Everlasting-pea | 167 | 2020 |
| plant | Lathyrus tuberosus | Tuberous Pea | 7 | 1999 |
| plant | Lauraceae | a Lauraceae species (unidentified) | 1 | 2022 |
| plant | Laurus nobilis | Bay | 136 | 2019 |
| plant | Lavandula | a Lavandula species (unidentified) | 12 | 2021 |
| plant | Lavandula angustifolia | Garden Lavender | 17 | 2015 |
| plant | Lavatera maritima | a flowering plant | 1 | 1979 |
| plant | Legousia hybrida | Venus's-looking-glass | 52 | 2010 |
| plant | Lemna | a duckweed (unidentified) | 120 | 2020 |
| plant | Lemnaceae | a Lemnaceae species (unidentified) | 30 | 2018 |
| plant | Lemna gibba | Fat Duckweed | 261 | 2019 |
| plant | Lemna minor | Common Duckweed | 1813 | 2020 |
| plant | Lemna minuta | Least Duckweed | 209 | 2019 |
| plant | Lemna trisulca | Ivy-leaved Duckweed | 531 | 2019 |
| plant | Leontodon | a hawkbit (unidentified) | 148 | 2019 |
| plant | Leontodon hispidus | Rough Hawkbit | 1994 | 2021 |
| plant | Leontodon hispidus x saxatilis | a hawkbit | 2 | 2016 |
| plant | Leontodon saxatilis | Lesser Hawkbit | 793 | 2021 |
| plant | Leonurus cardiaca | Motherwort | 2 | 2019 |
| plant | Lepidium bonariense | Argentine Pepperwort | 2 | 1922 |
| plant | Lepidium campestre | Field Pepperwort | 130 | 2019 |
| plant | Lepidium coronopus | Swine-cress | 924 | 2020 |
| plant | Lepidium didymum | Lesser Swine-cress | 942 | 2020 |
| plant | Lepidium draba | Hoary Cress | 376 | 2021 |
| plant | Lepidium draba subsp. chalepense | a hoary cress | 1 | 1991 |
| plant | Lepidium draba subsp. draba | a hoary cress | 3 | 2005 |
| plant | Lepidium graminifolium | Tall Pepperwort | 3 | 1925 |
| plant | Lepidium heterophyllum | Smith's Pepperwort | 11 | 2004 |
| plant | Lepidium latifolium | Dittander | 14 | 2011 |
| plant | Lepidium perfoliatum | Perfoliate Pepperwort | 4 | 1939 |
| plant | Lepidium ruderale | Narrow-leaved Pepperwort | 24 | 2017 |
| plant | Lepidium sativum | Garden Cress | 6 | 2016 |
| plant | Lepidium virginicum | Least Pepperwort | 13 | 2019 |
| plant | Leptochloa | a Leptochloa species (unidentified) | 1 | 2021 |
| plant | Leptospermum | a myrtle (unidentified) | 1 | 2002 |
| plant | Leucanthemum | a Leucanthemum species (unidentified) | 3 | 2014 |
| plant | Leucanthemum lacustre x maximum = L. x superbum | Shasta Daisy | 34 | 2017 |
| plant | Leucanthemum vulgare | Oxeye Daisy | 4546 | 2022 |
| plant | Leucojum | a Leucojum species (unidentified) | 1 | 2012 |
| plant | Leucojum aestivum | Summer Snowflake | 10 | 2019 |
| plant | Leucojum aestivum subsp. pulchellum | a summer snowflake | 13 | 2011 |
| plant | Leucojum vernum | Spring Snowflake | 2 | 2009 |
| plant | Leycesteria | a Leycesteria species (unidentified) | 12 | 2015 |
| plant | Leycesteria formosa | Himalayan Honeysuckle | 111 | 2020 |
| plant | Leymus arenarius | Lyme-grass (plant) | 30 | 2017 |
| plant | Ligustrum | a privet (unidentified) | 625 | 2022 |
| plant | Ligustrum lucidum | Tree Privet | 7 | 2015 |
| plant | Ligustrum ovalifolium | Garden Privet | 379 | 2019 |
| plant | Ligustrum vulgare | Wild Privet | 3769 | 2021 |
| plant | Liliaceae | a Liliaceae species (unidentified) | 2 | 2020 |
| plant | Lilium martagon | Martagon Lily | 2 | 1998 |
| plant | Limnanthes douglasii | Meadow-foam | 3 | 2015 |
| plant | Limonium binervosum | Rock Sea-Lavender | 4 | 1999 |
| plant | Limonium binervosum agg. | Rock Sea-Lavender [agg.] | 20 | 2003 |
| plant | Limonium platyphyllum | Sea-lavender | 1 | 2018 |
| plant | Limonium procerum | a Rock Sea-lavender | 3 | 2014 |
| plant | Limonium procerum subsp. procerum | a Rock Sea-lavender | 21 | 2012 |
| plant | Limonium vulgare | Common Sea-lavender | 60 | 2019 |
| plant | Limosella aquatica | Mudwort | 4 | 2003 |
| plant | Linaria | a Linaria species (unidentified) | 9 | 2020 |
| plant | Linaria alpina | a flowering plant | 1 | 2002 |
| plant | Linaria dalmatica | Balkan Toadflax | 1 | 1933 |
| plant | Linaria maroccana | Annual Toadflax | 4 | 2016 |
| plant | Linaria purpurea | Purple Toadflax | 584 | 2021 |
| plant | Linaria purpurea x repens = L. x dominii | a toadflax | 4 | 2009 |
| plant | Linaria repens | Pale Toadflax | 86 | 2012 |
| plant | Linaria supina | Prostrate Toadflax | 7 | 1999 |
| plant | Linaria vulgaris | Common Toadflax | 733 | 2021 |
| plant | Linaria vulgaris x repens = L. x sepium | a flowering plant | 5 | 2008 |
| plant | Linum bienne | Pale Flax | 86 | 2021 |
| plant | Linum catharticum | Fairy Flax | 1143 | 2020 |
| plant | Linum perenne | Perennial Flax | 2 | 2013 |
| plant | Linum usitatissimum | Flax | 38 | 2020 |
| plant | Liquidambar | a Liquidambar species (unidentified) | 1 | 2015 |
| plant | Liquidambar styraciflua | Sweet Gum | 23 | 2019 |
| plant | Liriodendron tulipifera | Tulip Tree | 46 | 2019 |
| plant | Listera | a twayblade (unidentified) | 5 | 2016 |
| plant | Lithocarpus edulis | Japanese Stone-oak | 1 | 2005 |
| plant | Lithodora diffusa | a flowering plant | 1 | 2012 |
| plant | Lithospermum | a Lithospermum species (unidentified) | 1 | 1993 |
| plant | Lithospermum arvense | Field Gromwell | 22 | 2002 |
| plant | Lithospermum officinale | Common Gromwell | 220 | 2020 |
| plant | Lithospermum purpureocaeruleum | Purple Gromwell | 59 | 2020 |
| plant | Littorella uniflora | Shoreweed | 3 | 2016 |
| plant | Lobelia | a lobelia (unidentified) | 5 | 2019 |
| plant | Lobelia erinus | Garden Lobelia | 35 | 2020 |
| plant | Lobularia maritima | Sweet Alison | 162 | 2019 |
| plant | Lolium | a Lolium species (unidentified) | 16 | 2021 |
| plant | Lolium multiflorum | Italian Rye-grass | 483 | 2020 |
| plant | Lolium multiflorum x temulentum | a rye-grass | 1 | 1930 |
| plant | Lolium perenne | Perennial Rye-grass | 6309 | 2022 |
| plant | Lolium perenne x multiflorum = L. x boucheanum | Hybrid Rye-grass | 12 | 2002 |
| plant | Lolium persicum | a flowering plant | 2 | 1955 |
| plant | Lolium rigidum | Mediterranean Rye-grass | 3 | 1954 |
| plant | Lolium temulentum | Darnel | 11 | 1985 |
| plant | Lonicera | a honeysuckle (unidentified) | 110 | 2020 |
| plant | Lonicera caprifolium | Perfoliate Honeysuckle | 4 | 1992 |
| plant | Lonicera caprifolium x etrusca = L. x italica | Garden Honeysuckle | 1 | 1999 |
| plant | Lonicera fragrantissima x standishii = L. x purpusii | Winter Flowering Honeysuckle | 3 | 2018 |
| plant | Lonicera japonica | Japanese Honeysuckle | 31 | 2020 |
| plant | Lonicera nitida | Wilson's Honeysuckle | 306 | 2021 |
| plant | Lonicera periclymenum | Honeysuckle | 2777 | 2022 |
| plant | Lonicera pileata | Box-leaved Honeysuckle | 16 | 2019 |
| plant | Lonicera xylosteum | Fly Honeysuckle | 9 | 2011 |
| plant | Lotus | a bird's-foot-trefoil (unidentified) | 79 | 2020 |
| plant | Lotus angustissimus | Slender Bird's-foot-trefoil | 3 | 2005 |
| plant | Lotus corniculatus | Common Bird's-foot-trefoil | 5360 | 2022 |
| plant | Lotus corniculatus var. sativus | a bird's-foot-trefoil | 2 | 2017 |
| plant | Lotus pedunculatus | Greater Bird's-foot-trefoil | 1139 | 2020 |
| plant | Lotus tenuis | Narrow-leaved Bird's-foot-trefoil | 63 | 2019 |
| plant | Luma apiculata | Chilean Myrtle | 5 | 2000 |
| plant | Lunaria annua | Honesty | 436 | 2020 |
| plant | Lunaria rediviva | a honesty | 1 | 2005 |
| plant | Lupinus | a Lupin (unidentified) | 2 | 2012 |
| plant | Lupinus angustifolius | Narrow-leaved Lupin | 5 | 1985 |
| plant | Lupinus arboreus | Tree Lupin | 3 | 1999 |
| plant | Lupinus arboreus x polyphyllus = L. x regalis | Russell Lupin | 3 | 2000 |
| plant | Luzula | A wood-rush (unidentified) | 7 | 2014 |
| plant | Luzula campestris | Field Wood-rush | 1690 | 2020 |
| plant | Luzula multiflora | Heath Wood-rush | 81 | 2019 |
| plant | Luzula multiflora subsp. congesta | a heath wood-rush | 7 | 2015 |
| plant | Luzula multiflora subsp. multiflora | a heath wood-rush | 1 | 2015 |
| plant | Luzula pilosa | Hairy Wood-rush | 181 | 2019 |
| plant | Luzula sylvatica | Great Wood-rush | 131 | 2020 |
| plant | Lychnis | a lychnis plant (unidentified) | 10 | 2021 |
| plant | Lycium | a teaplant (unidentified) | 6 | 2000 |
| plant | Lycium barbarum | Duke of Argyll's Teaplant | 62 | 2016 |
| plant | Lycium chinense | Chinese Teaplant | 20 | 2010 |
| plant | Lycopersicon esculentum | Tomato | 48 | 2020 |
| plant | Lycopus europaeus | Gipsywort | 665 | 2019 |
| plant | Lysimachia | a Lysimachia species (unidentified) | 2 | 2015 |
| plant | Lysimachia nemorum | Yellow Pimpernel | 274 | 2019 |
| plant | Lysimachia nummularia | Creeping-Jenny | 749 | 2021 |
| plant | Lysimachia punctata | Dotted Loosestrife | 48 | 2019 |
| plant | Lysimachia vulgaris | Yellow Loosestrife | 59 | 2018 |
| plant | Lythrum hyssopifolia | Grass-poly | 2 | 1930 |
| plant | Lythrum junceum | False Grass-poly | 3 | 2005 |
| plant | Lythrum portula | Water Purslane | 5 | 2016 |
| plant | Lythrum salicaria | Purple-loosestrife | 731 | 2021 |
| reptile | Lacerta | a Lacerta species (unidentified) | 1 | 2010 |
| sea-fan, sea anemone or jellyfish | Laomedea flexuosa | a Sea-fan/Sea Anemone/Jellyfish | 2 | 1974 |
| slime mould | Lamproderma columbinum | a slime mould | 3 | 2008 |
| slime mould | Leocarpus fragilis | a slime mould | 1 | 2013 |
| slime mould | Licea belmontiana | a slime mould | 1 | 2008 |
| slime mould | Licea biforis | a slime mould | 1 | 2008 |
| slime mould | Licea bryophila | a slime mould | 3 | 2008 |
| slime mould | Licea eleanorae | a slime mould | 1 | 2008 |
| slime mould | Licea kleistobolus | a slime mould | 1 | 2008 |
| slime mould | Licea marginata | a slime mould | 1 | 2008 |
| slime mould | Licea microscopica | a slime mould | 4 | 2008 |
| slime mould | Licea operculata | a slime mould | 1 | 2008 |
| slime mould | Licea parasitica | a slime mould | 6 | 2008 |
| slime mould | Licea pygmaea | a slime mould | 1 | 2008 |
| slime mould | Licea sambucina | a slime mould | 2 | 2008 |
| slime mould | Licea variabilis | a slime mould | 1 | 2008 |
| slime mould | Lindbladia tubulina | a slime mould | 1 | 2008 |
| slime mould | Lycogala | a Lycogala species (unidentified) | 5 | 2017 |
| slime mould | Lycogala epidendrum | a slime mould | 49 | 2020 |
| slime mould | Lycogala terrestre | a slime mould | 46 | 2017 |
| spider | Labulla thoracica | a money spider | 11 | 2017 |
| spider | Larinioides cornutus | Furrow Orbweaver | 64 | 2019 |
| spider | Larinioides sclopetarius | an orb-weaver spider | 3 | 2018 |
| spider | Lathys humilis | a mesh webbed spider | 5 | 1999 |
| spider | Latrodectus sp. | a widow spider (unidentified) | 1 | 1992 |
| spider | Lepthyphantes | a Lepthyphantes money spider (unidentified) | 4 | 2020 |
| spider | Lepthyphantes leprosus | a money spider | 5 | 2014 |
| spider | Lepthyphantes minutus | a money spider | 5 | 1997 |
| spider | Linyphia hortensis | a money spider | 13 | 2012 |
| spider | Linyphia triangularis | a money spider | 39 | 2020 |
| spider | Linyphiidae | a money spider (unidentified) | 14 | 2018 |
| spider | Liocranum rupicola | a running foliage spider | 2 | 2013 |
| spider | Lophomma punctatum | a money spider | 1 | 2012 |
| spider | Lycosidae | a wolf spider (unidentified) | 18 | 2016 |
| springtail | Lepidocyrtus cyaneus | a springtail (Collembola) | 2 | 2021 |
| stonefly | Leuctra | a leuctra stonefly (unidentified) | 11 | 2012 |
| stonefly | Leuctra nigra | a stonefly | 2 | 2000 |
| tapeworm (cestoda) | Ligula intestinalis | a tapeworm (Cestoda) | 2 | 1939 |
| tick or mite (acarine) | Lebertia | a Lebertia species (unidentified) | 2 | 1991 |
| tick or mite (acarine) | Limnesia | a Limnesia species (unidentified) | 3 | 1991 |
| true fly - | Lasiambia brevibucca | a fly | 2 | 2020 |
| true fly - | Lasiomma seminitidum | a fly | 2 | 2002 |
| true fly - | Lauxaniidae | a Lauxaniidae species (unidentified) | 2 | 2010 |
| true fly - | Leiomyza laevigata | a fly | 1 | 1996 |
| true fly - | Leiomyza scatophagina | a fly | 1 | 2000 |
| true fly - | Leptocera fontinalis | a lesser dung fly | 2 | 2002 |
| true fly - | Leptocera nigra | a lesser dung fly | 3 | 2002 |
| true fly - | Leptogaster | a Leptogaster species (unidentified) | 1 | 2014 |
| true fly - | Leptopa filiformis | a dung fly | 1 | 1999 |
| true fly - | Leptosciarella pilosa | a fly | 1 | 1997 |
| true fly - | Leptosciarella trochanterata | a fly | 2 | 2020 |
| true fly - | Leucophenga maculata | a fruit fly | 3 | 2003 |
| true fly - | Leucophora personata | a fly | 2 | 2006 |
| true fly - | Limnellia quadrata | a shore fly | 3 | 2001 |
| true fly - | Limnellia stenhammari | a shore fly | 1 | 1994 |
| true fly - | Limnia | a snail-killing fly (unidentified) | 1 | 2011 |
| true fly - | Limnia unguicornis | a snail-killing fly | 29 | 2013 |
| true fly - | Limnophora maculosa | a muscid fly | 1 | 2000 |
| true fly - | Limnophora tigrina | a muscid fly | 4 | 2002 |
| true fly - | Limnospila albifrons | a muscid fly | 1 | 2000 |
| true fly - | Limonia | a Limonia species (unidentified) | 1 | 1997 |
| true fly - | Limoniidae | a Limoniidae species (unidentified) | 1 | 2017 |
| true fly - | Limosina silvatica | a lesser dung fly | 1 | 2002 |
| true fly - | Lipara lucens | a fly | 8 | 2015 |
| true fly - | Lipara rufitarsis | a fly | 1 | 2001 |
| true fly - | Lipoptena cervi | Deer Ked | 9 | 2021 |
| true fly - | Liriomyza | a Liriomyza species (unidentified) | 1 | 2015 |
| true fly - | Liriomyza amoena | a leaf-mining fly | 6 | 2015 |
| true fly - | Liriomyza centaureae | a leaf-mining fly | 1 | 2021 |
| true fly - | Liriomyza congesta | a leaf-mining fly | 2 | 2020 |
| true fly - | Liriomyza erucifolii | a leaf-mining fly | 1 | 2001 |
| true fly - | Liriomyza eupatorii | a leaf-mining fly | 6 | 2019 |
| true fly - | Liriomyza flaveola | a leaf-mining fly | 5 | 2003 |
| true fly - | Liriomyza flavopicta | a leaf-mining fly | 2 | 2006 |
| true fly - | Liriomyza hieracii | a leaf-mining fly | 1 | 2006 |
| true fly - | Liriomyza orbona | a leaf-mining fly | 1 | 2001 |
| true fly - | Liriomyza pascuum | a leaf-mining fly | 1 | 2020 |
| true fly - | Liriomyza phryne | a leaf-mining fly | 1 | 2001 |
| true fly - | Liriomyza strigata | a leaf-mining fly | 3 | 2020 |
| true fly - | Liriomyza tragopogonis | a leaf-mining fly | 2 | 2004 |
| true fly - | Liriomyza valerianae | a leaf-mining fly | 1 | 2020 |
| true fly - | Lispe litorea | a muscid fly | 2 | 2009 |
| true fly - | Lispe pygmaea | a muscid fly | 2 | 2004 |
| true fly - | Lispe tentaculata | a muscid fly | 2 | 2000 |
| true fly - | Lispocephala brachialis | a muscid fly | 1 | 1964 |
| true fly - | Lispocephala erythrocera | a muscid fly | 7 | 2009 |
| true fly - | Lispocephala spuria | a muscid fly | 1 | 1964 |
| true fly - | Lonchaea chorea | a fly | 3 | 2000 |
| true fly - | Lonchaea fraxina | a fly | 1 | 1977 |
| true fly - | Lonchaea fugax | a fly | 1 | 2006 |
| true fly - | Lonchaea postica | a fly | 1 | 2020 |
| true fly - | Lonchoptera | a Lonchoptera species (unidentified) | 2 | 2015 |
| true fly - | Lonchoptera bifurcata | a pointed-wing fly | 43 | 2013 |
| true fly - | Lonchoptera lutea | a pointed-wing fly | 41 | 2021 |
| true fly - | Lonchoptera tristis | a pointed-wing fly | 4 | 2003 |
| true fly - | Lonchopteridae | a Lonchopteridae species (unidentified) | 1 | 1997 |
| true fly - | Lophosia fasciata | a parasitic fly | 2 | 1999 |
| true fly - | Lordiphosa fenestrarum | a fruit fly | 5 | 2009 |
| true fly - | Lotophila atra | a lesser dung fly | 7 | 2013 |
| true fly - | Lucilia | a Lucilia true fly (unidentified) | 28 | 2020 |
| true fly - | Lucilia ampullacea | a blue bottle or green bottle | 2 | 2020 |
| true fly - | Lucilia caesar | a blue bottle or green bottle | 39 | 2021 |
| true fly - | Lucilia illustris | a blue bottle or green bottle | 3 | 2009 |
| true fly - | Lucilia richardsi | a blue bottle or green bottle | 1 | 2002 |
| true fly - | Lucilia sericata | a blue bottle or green bottle | 17 | 2017 |
| true fly - | Lucilia silvarum | a blue bottle or green bottle | 2 | 2010 |
| true fly - | Lunatipula | a Lunatipula species (unidentified) | 2 | 2010 |
| true fly - | Lycoriella ingenua | a fly | 1 | 2020 |
| true fly - | Lycoriella sativae | a fly | 2 | 1998 |
| true fly - | Lydella grisescens | a parasitic fly | 4 | 2006 |
| true fly - | Lydella stabulans | a parasitic fly | 4 | 2012 |
| true fly - cranefly | Limonia flavipes | a cranefly | 7 | 2019 |
| true fly - cranefly | Limonia macrostigma | a cranefly | 1 | 2003 |
| true fly - cranefly | Limonia nubeculosa | a cranefly | 63 | 2021 |
| true fly - cranefly | Limonia phragmitidis | a cranefly | 8 | 2021 |
| true fly - cranefly | Limonia trivittata | a cranefly | 3 | 2021 |
| true fly - cranefly | Lipsothrix remota | a cranefly | 3 | 2000 |
| true fly - (diptera) | Lasiambia palposa agg. | an insect - true fly (Diptera) | 2 | 2009 |
| true fly - (diptera) | Lasiosina intermedia | an insect - true fly (Diptera) | 2 | 2013 |
| true fly - (diptera) | Liriomyza pisivora | an insect - true fly (Diptera) | 1 | 2020 |
| true fly - hoverfly | Lejogaster metallina | a hoverfly | 13 | 2021 |
| true fly - hoverfly | Lejogaster tarsata | a hoverfly | 1 | 2020 |
| true fly - hoverfly | Leucozona glaucia | a hoverfly | 49 | 2016 |
| true fly - hoverfly | Leucozona laternaria | a hoverfly | 19 | 2018 |
| true fly - hoverfly | Leucozona lucorum | a hoverfly | 126 | 2021 |
| true fly - midge, gnat or mosquito | Lasioptera rubi | a gall midge | 1 | 2004 |
| true fly - midge, gnat or mosquito | Leia bilineata | a fungus gnat | 1 | 1998 |
| true fly - midge, gnat or mosquito | Leia bimaculata | a fungus gnat | 2 | 2020 |
| true fly - midge, gnat or mosquito | Leia cylindrica | a fungus gnat | 2 | 2020 |
| true fly - midge, gnat or mosquito | Leia fascipennis | a fungus gnat | 2 | 2000 |
| true fly - midge, gnat or mosquito | Leia winthemii | a fungus gnat | 1 | 2001 |
| true fly - midge, gnat or mosquito | Limnophyes minimus | a non-biting midge | 2 | 1983 |
| true fly - picture-winged, conopid or stilt-legged fly | Leopoldius signatus | a fly | 4 | 2020 |
| true fly - robber, empid or dolichopid fly | Lasiopogon cinctus | Spring Heath Robberfly | 1 | 2006 |
| true fly - robber, empid or dolichopid fly | Leptarthrus brevirostris | Slender-footed Robberfly | 2 | 1992 |
| true fly - robber, empid or dolichopid fly | Leptogaster cylindrica | Striped Slender Robberfly | 65 | 2021 |
| true fly - robber, empid or dolichopid fly | Leptogaster guttiventris | Dashed Slender Robberfly | 4 | 2020 |
| true fly - robber, empid or dolichopid fly | Leptopeza flavipes | a dance fly | 4 | 2008 |
| true fly - robber, empid or dolichopid fly | Liancalus virens | a dolichopodid fly | 7 | 2016 |
| woodlouse | Lekanesphaera hookeri | a woodlouse or sea slater | 1 | 1906 |
| woodlouse | Lekanesphaera monodi | a woodlouse or sea slater | 1 | 2019 |
| woodlouse | Lekanesphaera rugicauda | a woodlouse or sea slater | 3 | 1939 |
| woodlouse | Ligia oceanica | Sea Slater | 23 | 2020 |
| woodlouse | Ligidium hypnorum | a woodlouse | 31 | 2015 |
| woodlouse | Limnoria lignorum | Gribble | 3 | 1939 |
| worm | Lanice conchilega | Sand Mason Worm | 1 | 1972 |
| worm | Lepidonotus squamatus | an annelid | 3 | 1937 |
| worm | Lumbricidae | an earthworm (unidentified) | 11 | 2017 |
| worm | Lumbriculus variegatus | an oligochaete | 5 | 2020 |
| worm | Lumbricus | a Lumbricus Earthworm (unidentified) | 5 | 2016 |
| worm | Lumbricus castaneus | Chestnut Worm | 55 | 2020 |
| worm | Lumbricus festivus | Ruddy Worm | 4 | 2017 |
| worm | Lumbricus rubellus | Red Worm | 42 | 2020 |
| worm | Lumbricus terrestris | Common Earthworm | 51 | 2020 |