By-catch Records

Running a moth-trap provides a window into many other insect groups because the attraction to light is not limited solely to moths.  Although it is impossible to do justice to everything, if time permits I do try my best to identify things which appear to me to be noteworthy, especially if I haven’t seen them before.   While this often means the larger or more spectacular-looking moth-trap visitors, it is by no means limited entirely to them.  Beetles probably offer the best chance of successful identification and regulars such as Cockchafer Melolontha melolontha, Summer Chafer Amphimallon solstitiale , Black Snail Beetle Silpha atrata and the very smelly Sexton Beetles are easy enough to identify by anyone.  A few of the water beetles, of which Colymbetes fuscus and the very large Dytiscus marginalis seem to me to be the most regular moth-trap visitors in Bucks, can be identified with care.  Most Ladybirds can be identified safely to species and our three largest Carabus ground beetles, which sometimes creep up to the light looking for an easy meal, can also be separated quite easily.

Common Cockchafer Melolontha melolontha

Eyed Ladybird Anatis ocellata, Stoke Common 15th May

Bronze Ground Beetle Carabus nemoralis consuming a
Small Brindled Beauty, Bernwood Forest 20th March

Other groups which will be familiar to all light-trappers include the trichoptera (caddis flies), of which there are some 200 species in the UK and Ireland and about half that number are known from Bucks.  In the right habitat at the right time of year they can sometimes outnumber the moths.  Few are recognisable solely by their shape or markings but one which can be recorded safely on sight is Glyphotaelius pellucidus with its distinct tornal notch.  The largest British caddis species is Phryganea grandis and a combination of sheer size and wing markings led me to that ID for the female illustrated below, which came to light on Coombe Hill on 5th July 2017, although one has to be careful  to eliminate the rather similar Phryganea unipuncta (sometimes only possible through inspection of the genitalia).

Caddis Glyphotaelius pellucidus, Westcott 16th April

Caddis Phryganea grandis, Coombe Hill 5th July

 

Amongst the hymenoptera, many moth-trappers will no doubt be familiar enough with the Hornet Vespa crabro although other members of this group are nowhere near as easy to identify.  The mostly orange nocturnal ichneumonid wasps are regular visitors to light traps but unfortunately very few of them can be identified to species level without using a microscope.  Ophion obscuratus is the obvious exception, with its creamy-white stripes on the thorax, but there are other nondescript species (such as the early spring example below, Ophion scutellaris with its very long antennae) which can be identified with care and there are keys as well as the services of various experts which can be called upon if one is prepared to make the effort to pursue them further - and your records will always be very well received. 

Ichneumonid Wasp Ophion scutellaris, Westcott 11th March

 

A small selection of the many other light-trap visitors which I managed to identify during 2017 is illustrated below:

False Blister Beetle Oedemera femoralis, Coombe Hill 9th April

Long-horn Beetle Stenocorus meridianus, Bernwood 10th June

Emperor Dragonfly Anax imperator, Westcott 23rd June

Downland Bee-fly Villa cingulata, Hog Wood 26th June



Tanner Beetle Prionus coriarius, Hog Wood 17th July

Eared Leafhopper Ledra aurita, Westcott 7th September

Beetle Chrysolina banksii, Finemere Wood 22nd December

Other groups such as lacewings, harvestmen and spiders appear frequently at light traps and identifications can be pursued either through on-line keys, via iSpot or the iRecord app or else through their various recording schemes, although in many cases a specimen will be required as it is not always possible to confirm the species from a photograph.

Of course, being able to name these insects is not the end of the matter and, once the correct identification has been verified, it is equally as important to ensure that the information does at the very least find its way to your local environmental records centre!