Distinctive invertebrates in light traps*

Very many insects and other invertebrates turn up in light traps. Often this is not the result of attraction to

the light itself. The invertebrate could be hunting, seeking refuge, looking for a mate or merely the trap was

in it’s path. Most non-Lepidopteran insects will need examination under a microscope for definitive

identification. This guide aims to highlight some species than can be safely identified from adequate images of

the whole insect. This brief guide includes just a few species and is by no means comprehensive, even in

terms of easy-to-identify insects. Suggestions for additions are welcomed to

gary.hedges@liverpoolmuseums.org.uk.

*Excluding moths!

(Apocrita, Hymenoptera)

(Parasitica, Hymenoptera

Grasshoppers and (Orthoptera)

Shortcuts to taxon groups

Last update: August 2017

Craneflies Craneflies

Craneflies

Craneflies

Carrion Beetles

Craneflies

Lacewings Social Wasps

Diving Beetles Caddisflies Craneflies

Nocturnal Ichneumonids

Crickets

Sheildbugs Leafhoppers

We recommend using iRecord to submit all sightings of species appearing in this guide.

Pedicia rivulosa

Notes

• Widespread in Britain

• Flight period: April to September

• Prefers wet and marshy areas

• Very large: wing length 20 – 24 mm

Safe identification

• Wing pattern quite unlike any

other British cranefly, with

brown markings that create a

large cell in the centre of each

wing.

Dark edged pale ‘half moon’ at outer edge of

forewings. Edging often much darker than this.

Craneflies (Tipulidae, Diptera)

Tipula maxima

Safe identification

• Wings heavily patterned unlike any

other British cranefly including

three dark blotches along the costa

• Very large size (100 mm leg span)

Notes

• Common and widespread in Britain

• Prefers wet habitats such as marshes

and bogs

• Flight period: April to August

Three large dark blotches along

the front margins of the wings

Gail Hampshire -CC BY-2.0

Morten Staerkeby CC BY-NC 2.0

Brown pattern creates ‘cell’ in

centre of wings

Limnephilus lunatus

Notes

• Common and widespread in Britain

• Almost ubiquitous

• Flight period: May to November

• 14-16 mm forewing length

Safe identification

• All you need to see is a clear dark

edged pale ‘half moon’ as shown.

Forewing can be various shades of

brown.

• WARNING – Two similar, rare species

occur in highland Scotland; L. borealis

and L. subcentralis. Be sure to submit

images on iRecord and if a very

unlikely rarity turns up, it will be

spotted by Ian Wallace. Sanja565658 - CC BY-SA 3.0,

Dark edged pale ‘half moon’ at outer edge of forewings.

Edging often much darker than this image shows..

Caddisflies (Trichoptera)

Donald Hobern

https://creativecommons.org/licenses/by/2.0

Glyphotaelius pellucidus

Safe identification

• The only English caddis with a clear

notch in the forewings.

• WARNING – rare species with

notch, Nemotaulius punatolineatus,

occurs in Scotland (Caithness and

Sutherland) but is much larger:

forewing length 22 – 26 mm.

Notes

• Common and widespread in

Britain

• Larvae live in still water habitats

• Flight period: May to October

• 12 – 17 mm forewing length

Forewings with notch in

outer margin

Caddisflies (Trichoptera)

Donald Hobern CC-BY-2.0

Mystacides longicornis

Safe identification

Must have a combination of:

• Very long antennae – about twice that

of the forewing length

• Sandy coloured forewings with

diagonal black bars.

N.B. An uncommon, less distinctive, all

yellow form of this species also occurs

Notes

• Very common and widespread in

Britain

• lake species

• Flight period: June to August

• 8-9 mm forewing length

Antennae about twice

as forewings

Black bars on sandy

coloured forewing

Grasshoppers and Crickets (Orthoptera)

Speckled Bush-cricket

Leptophyes punctatissima

Safe identification

• Only British cricket with

body covered in tiny

black speckles / dots,

seen on both adults and

nymphs.

Legs and body covered

in tiny black spots.

Females with sword-like ovipositor

and pale stripe on back. Male has

brown stripe and no ovipositor.

Notes

• Common in Southern Britain

but local (increasing) in the

North West

• Inhabit gardens

Very long antennae

means it’s a cricket

Copyright Phil Smith

Ilybius fuliginosus

Notes

• Common and widespread

• Peaks in June but adults

recorded throughout year

• Medium sized diving beetle

• Regular in light traps

Safe identification

Must have a combination of the

following:

• 10-11.5 mm in length

• Strong yellow streaks running

along side of elytra

• Narrow ‘torpedo’ body shape

Variable but strong yellow streak running along each side

of elytra. More obvious in living specimens.

Diving Beetles (Dytiscidae, Coleoptera)

Donald Hobern

https://creativecommons.org/licenses/by/2.0

Great Diving Beetle

Dytiscus marginalis

Safe identification

• Must be >26 mm in length

• All margins of pronotum must

have a yellow band

• Metacoxal processes must be

blunt – all other very large

British diving beetles with

fully yellow pronotum

margins have sharp metacoxal

processes

Notes

• Common and widespread

• Peaks in May and Sept but

adults recorded all year

• Very large: 26-32 mm

Relatively blunt

metacoxal processes

Very sharp metacoxal

processes

Yellow bands

all the way

around margin

of pronotum

Male: smooth elytra and

sucker pads on front legs

Female: ridged elytra

and no sucker pads

Udo Schmidt CC BY-SA 2.0 Udo Schmidt CC BY-SA 2.0

Udo Schmidt CC BY-SA 2.0

S. Rae CC BY-SA 2.0

Necrodes littoralis

Notes

• Common and regularly attends light traps

• Large: variable in size up to 25 mm

Safe identification

One of only two large black burying beetles

(>15mm) with orange on antennae, both of

which come to light (the other, Nicrophorus

humator is above). Identified at a glance with

practise.

See above for differences between N. littoralis and

N. humator.

Dark edged pale ‘half moon’ at outer edge of

forewings. Edging often much darker than this.

Carrion Beetles (Silphidae, Coleoptera)

Nicrophorus humator

Safe identification

One of only two large black burying beetles

(>15mm) with orange on antennae, both of which

come to light (the other, Necrodes littoralis, is

below). Identified at a glance with practise.

Differences: between N. humator and N. littoralis

• N. humator has more clubbed antennae

• N. humator has shiny elytra – dull in N. littoralis

• N. humator has a smoother appearance to elytra

(not very obviously ridged)

• N. humator has obviously ‘hairy shoulders’

Notes

• Common and widespread in Britain

• Adults: April to September

• Large: 20-30 mm in length

Janet Graham CC-BY-2.0

Relatively

shiny and

smooth elytra Rounded

clubs

Long hairs

on shoulders

– may rub off

on worn

specimens

Janet Graham CC-BY-2.0

Dull / matt

elytra. Not

shiny.

Elongate tips to

antennae. In

some images,

looks clubbed.

Hairs on

shoulders

on visible

under a

microscope

Nicrophorus interruptus

Notes

• Scarce and no recorded in Lancashire and

Cheshire but occurs North and South of the

region

• Large: variable in size up to 20 mm

Safe identification

Your beetle must have all of the following

features:

• Partly orange antennae

• No yellow hairs on the thorax

• Two broad orange bands on elytra

Then see differences above with the very

similar N. investigator. If you find N.

interruptus, a voucher specimen should be

collected for verification.

Usually a gap

in front band

on elytra

Carrion Beetles (Silphidae, Coleoptera)

Nicrophorus investigator

Safe identification

Your beetle must have all of the following features:

• Partly orange antennae

• No yellow hairs on the thorax

• Two broad orange bands on elytra

Then differences with the very similar N. interruptus:

Notes

• Common and regularly attends light traps

• Adults Spring and Summer

• Large but variable: up to 22mm in length

Martin Harvey CC-BY-SA -2.0

Usually no gap

in front orange

band on elytra.

Narrow if

present

Partly orange

antennae

No yellow hairs on

front of thorax

Janet Graham CC-BY-2.0

No yellow

hairs on front

of thorax

Tergites mainly fringed

with black / dark brown

hairs – not easily seen

All tergites

fringed with

golden hairs –

more obvious

with hand lens

• N. investigator tergites mostly fringed with black

or dark brown hairs. Only last tergite with golden

hairs. N. interruptus has all abdominal tergites

fringed with golden hairs.

• N. investigator usually with no gap in front

orange band. N. interruptus usually has one.

Partly

orange

antennae

Nothochrysa capitata

Notes

• Widespread but local in Britain

• Generally associated with pine and

sometimes found on oak

• Flight period: Summer and early Autumn

Safe identification

• One of only two orange lacewings in

Britain.

• This is the only species with an

entirely reddish-brown thorax and

pronotum. The only similar

(extremely rare) species

(Nothochrysa fulviceps) has a broad

pale longitudinal stripe running

through the thorax and pronotum.

Dark edged pale ‘half moon’ at outer edge of

forewings. Edging often much darker than this.

Lacewings (Neuroptera)

Giant Lacewing

Osmylus fulvicephalus

Safe identification

Tick off all of the following: • Good general match to this image • Body not green • Very large (c.25 mm incl. wing length) • Black spots on the wings. • There are a couple of other lacewings

almost as large but green and without black markings

Notes

• Widespread and common in Southern England, becoming local further North.

• Stony streams • Flight period: May and June

Many black spots on wings

c.25 mm Pierre Bornand CC BY 2.0

Donald Hobern, CC BY 2.0

Pronotum = entirely reddish brown

Thorax = entirely orange-brown

Udo Schmidt CC BY-SA 2.0

Nocturnal Ichneumonids (Parasitica, Hymenoptera)

Enicospilus ramidulus

End of abdomen

black-tipped

Safe identification

Your wasp must clearly have

both features as highlighted in

the image (right). No other

orange ichneumonid has the

combination of these features.

Not reliable if wasp was found

dead as abdomens can blacken.

Two small marks (sclerites)

in the centre of the forewing

Copyright: Nigel Gilligan

Notes

• Common and widespread in

Britain

• Parasitoid of noctuid moth

larvae

• Flight period: July to

September

Recording related species

Most need detailed study.

Keys available from the

Recording Scheme website

Gavin Broad

Safe identification

• Thorax should be reddish-

brown and black with no

yellow markings

• Reddish brown colours on

legs and abdomen.

• Most similar species

Dolichovespula media has

yellow markings on thorax.

Notes

• Widespread in Southern Britain.

Scarce but increasing in

Lancashire and Cheshire

• Flight period: May to November

• Length: 25–35 mm

European Hornet

Vespa crabro

Social Wasps (Vespidae, Hymenoptera)

Reddish-brown colours on

legs and abdomen

Thorax reddish-brown and

black with no yellow

markings

Jurgen Mangelsdorf CC BY-NC-ND 2.0

Related species: Most need detailed study. Keys available from the Recording Scheme website

Netelia melanura

Notes

• Flies July to October

• Parasitoid of noctuid moth

larvae in low vegetation

Safe identification

• Your wasp must have a wholly

orange body apart from the

sharply black-tipped abdomen

and no small marks in the

wings as in the previous

species.

• Your wasp must also have an

orange triangle 2/3 along the

leading edge of the forewing.

Related species: Most need detailed study. Keys available from the Recording Scheme website

Ophion ventricosus

Safe identification

Combination of black markings (as

shown) and shiny yellow wing

membrane will leave you with

Eremotylus marginatus as the only

other possibility but that species has

a curved vein exiting the

pterostigma and is only known from

South England where it is rare.

Black tip to abdomen

Triangular areolet

No dark dots in

forewing. All

orange body

apart from

black abdomen

tip

Females

with

ovipositor

Notes

• Local in Britain

• but can be abundant in

ancient, deciduous woodland

parasitoid of Pale Brindled

Beauty

• Flies mid-April to late June

Black markings on

head and underside

of thorax.

Shiny yellow wing

membrane will be more

obvious than this.

Vein exiting pterostigma

almost straight Pterostigma

Nocturnal Ichneumonids (Parasitica, Hymenoptera)

Related species: Most need detailed study. Keys available from the Recording Scheme website

Copyright: Gordon Woolcock

Copyright: Ab H. Bass

Sheildbugs (Pentatomoidea)

Phil Smith

Red-legged Sheildbug

Pentatoma rufipes

Safe identification of adults

• The only British sheildbug,

which had a combination of

red legs and a pale (orange

to cream) tip to the

scutellum.

Notes

• Common and widespread in Britain

• Occurs in various habitats

• Adults: July to November

• Length 11-14 mm

The adult stage had

fully formed wings

which cover all but

the edge of

abdomen

Pale tip to

scutellum,

varying from

cream to orange

Red legs

Copyright: Phil Smith

Eared Leafhopper

Ledra aurita

Notes

• Mainly Southern and not yet recorded

from Cheshire and Lancashire but has

been found in South Cumbria so possibly

awaiting discovery.

• Very large: 13-18mm in length

• Usually found on lichen-covered trees

Safe identification of adults

The only British leafhopper with ear-like

projections on the pronotum.

Ear-like projections on

pronotum

Vlad Proklov, CC BY 2.0

Leafhoppers (Cicadellidae)

Related species: Other adult shieldbugs can usually be identified from images. See British Bugs website.

Related species: some other adult leafhoppers can be identified from images. See British Bugs website.