Phytomyza flavicornis

Popped the water trap out again today and caught a rather attractive agromyzid fly, keying to Phytomyza flavicornis.  The Agromyzidae spend their larval life as miners or borers of plant tissue, pupating in the plant or in the ground nearby.  The flavicornis refers to the yellow (flavus) antennae (corne).  This species combines yellow coloration on the legs, top of head, sides of thorax and antennae along with darkened top of thorax and scutellum.  The larvae feed on the stems of stinging nettles and the adults emerge quite early in the year.  There didn't seem to be a definitive image of the species on the net so I thought I would put one here.  The specimen is a male. It is taken in water (thus a few spots due to the lighting) and made into a composite image of 15 photographs using Zerene Stacker software.

Psychoda albipennis

Cleared the Psychoda female from Saturday 8th March in potassium hydroxide for 24 hours and then washed in water.  Transferred to a microscope slide and abdomen removed using mounted needles.  Checked that it was lower surface upwards and then cover slip on top.  Traced it through the key to Psychodidae and keyed easily to Psychoda albipennis.  The shape of the subgenital plate is different from our other species so it should be possible to identify this species again with confidence at reasonably low power using the binocular microscope.  The photos show the whole insect as it would be seen in a water trap sample, the abdomen cleared,  viewed from below and the detail of the subgenital plate under high power.  As an aside saw probably my last redwings of the winter today, a flock of 8 heading northwards.

Spring, reports time and a plethora of insects

Last weekend was the first really spring-like weather.  Walking to church on Sunday was great hearing folk chatting in their gardens, catching up on the jobs and generally happy.  The year's first blackcap was singing away happily.  Back home five species of butterfly were on the wing - small white, peacock, small tortoiseshell, comma and brimstone and there was plenty to look at in the water trap.  There had obviously been a mass emergence of the ephydid fly Hydrellia griseola and there were other species there as well.  It being busy time with report writing at work, time has been squeezed, so the trap has been bought inside for another time. 

I had a key to the whirligig beetles of Britain on the go so that is now published on the website at https://sites.google.com/site/mikesinsectkeys/Home/keys-to-coleoptera/gyrinidae.  Do have a look.  The photographs from the Polish collection are as usual really nice.

So back to reports...

More Chrysomelid keys (leaf beetles)

Rather than put out the water trap for the last few days I've been concentrating on getting some more of the beetle keys into a publishable state.  You will now find there are keys to genera of all the subfamilies of Chrysomelidae (leaf beetles) at https://sites.google.com/site/mikesinsectkeys/Home/keys-to-coleoptera/chrysomelidae.  The key to subfamilies has been updated to take account of genus Phratora which would have keyed into the wrong subfamily.  I have also completed keys to the British species of subfamilies Bruchinae, Cassidinae and Donaciinae.  The keys to species of subfamilies Chrysomelinae and Galerucinae are still very much works in progress.  In the Chrysomelinae, the sticky genus is Chrysolina which is unsatisfactory in Joy's Handbook but the translation from the German key is leading to some problems in interpretation that I really need to examine museum material to unravel.  The Galerucinae is such a large subfamily that it will be some time before I complete it.  Tribe Galerucini is done and is now on the website along with the large genus Longitarsus from tribe Alticini.  You will have to wait for the rest I'm afraid.

If you use the keys please send me feedback as I'm keen to improve them so they are a useful tool for British entomologists.

Here's a picture of a female of genus Psychoda caught today.  In order to get it to species I need to examine the subgenital plate at high power so it is popped into the potassium hydroxide for 24 hours and then I'll update the ID.

Longitarsus luridus

After working on translating the key to genus Longitarsus to identify all the British species, it turns out that the species I had collected earlier in the week was the commonest one in the country.  Still the world now has a reasonable illustrated key to the British species of the genus at https://sites.google.com/site/mikesinsectkeys/Home/keys-to-coleoptera/chrysomelidae.  It does seem that host plant is going to be very important in the identification and I hope to do some targeted collection to increase my familiarity with the genus.

  

Philosepidon humeralis

After a couple of days of catching nothing but springtails, caught a male psychodid fly, a very small beetle of genus Longitarsus (Chrysomelidae) and Empoasca vitis (Cicidellidae, Hemiptera).

The psychodid fly keyed to Psilosepidon humeralis,  This was a very simple identification and you might be able to pick out the defining features on the image below.  It was photographed again in water so the stacking software tried to stack tiny bits suspended in the water.  There are two forked veins on the wings with two veins in between.  The lower processes at the end of the abdomen run horizontally and then vertically, each of them bearing two very thin projections which have the appearance of matchsticks with a darkened slightly swollen head.  Eaton (1904) mentions the palps are very long - these are the segmented mouthparts extending from below the head.  You can see that they are longer than the height of the head.  I last saw this species on 30th June 1990 in Bishopstoke so it was nice to see it again.  The antennae have 16 segments with the last three tiny and rounded (one has fallen off one of the antennae) and the 13th segment has no neck.

Colydiidae key and Tephrochlamys rufiventris

The illustrated key to the twelve species of wood-boring beetles of family Colydiidae, translated from the German can now be found at https://sites.google.com/site/mikesinsectkeys/Home/keys-to-coleoptera/colydiidae.  I was awaiting permission from the copyright holder of one of the images before publishing it.  If you have any specimens of the family please give the key a go.  I'm sorry about the first couplet as this involves viewing the underside of the beetle which might be difficult depending on how the specimen is mounted.  Please send me any comments on how it can be improved.

Some slightly larger species are now turning up in the water trap with a male Tephrochlamys rufiventris illustrated today.  This has been the commonest member of family Heleomyzidae in my garden.  The family is characterised by the bristles along the leading edge of the wing; some are stronger and then there are weaker ones in between.  There are several other families with this arrangement.  The Heleomyzidae are identified by the combination of a strong pair of bristles at the front of the mouth opening (called vibrissae), and a bristle on the top surface of the tibia of the back leg (you can just about see that on the photograph).  To identify this species combine the colour pattern with the presence of two backwardly curved bristles on top of the head above the eyes, a distinct bristle on the head below the lower back edge of the eye and the long bristles on the top of the thorax starting behind the suture that crosses the thorax.