Wednesday 26 February 2014

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.


Tuesday 25 February 2014

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.

Sunday 23 February 2014

Ectopsocus briggsi and female chironomid

Today's catch in the yellow water trap was a bit disappointing as most of the diptera were females which are more tricky to identify. 

Ectopsocus briggsi however was straightforward and is illustrated below meaning two members of Psocoptera have turned up in the past week or so. 



A female chironomid keyed to subfamily Orthocladiinae with the front tibia longer than the first segment of the front tarsus.  The wings, squama and eyes were all bare.  It is probably Smittia pratorum which I've found as the male before in the garden. 



Saturday 22 February 2014

Trioza urticae

In yesterday's catch in the water trap was a female of Trioza urticae, which means that two of the four common members of family Triozidae have turned up in my garden in February.  There are 19 species on the British list in this family in four genera.  Of these six are rare or based on very few records and six are uncommon.  Of the remaining seven, four are locally common and three are common to very common.  One of the remaining common species is associated with oaks and the other with willows, so the latter could turn up with the ornamental willows in the garden.  There are no oaks particularly nearby. 

Today's image shows Lauritrioza alacris and Trioza urticae next to one another.  They differ in particular in the length of the front vein which goes past the Y-fork in the second vein in Trioza and ends well short of the fork in Lauritrioza.  Below the eyes there are two triangular projections known as the genal cones.  These are pale in Lauritrioza and black in Trioza.  Seen side by side a number of other differences are apparent.  Lauritrioza alacris is associated with bay trees (scientific name Laurus nobilis - hence the insect's name).  Trioza urticae is found on nettles (Urtica dioica -again giving the insect its name)

Omitted to mention that the frogs were in the pond well over a week earlier this year although they have not begun spawning yet.  This year it there were sixteen in the pond on the 19th February; last year it was the first week of March before any turned up.

  

Trichopsocus brincki and Lauritrioza alacris

Put out a yellow pan trap (yellow plate containing water and a couple of drops of washing up liquid) to catch insects in the garden at the beginning of February and this has turned up some insects I had not seen before.

These included Trichopsocus brincki, a member of family Psocoptera (the bark lice).  Working from the old key this was identified to family Trichopsocidae due to the hairs on the back wing being alternately long and short (required about x100 magnification to see).  It was clear that the patterning on the wings didn't fit the species there so went to Keith Alexander's site and identified the species easily using the illustrations there of wing patterning (https://www.brc.ac.uk/schemes/barkfly/key/A1-B-C2.htm).  This was recorded on February 9th, 16th-18th and 21st.

A second one new to me was Lauritrioza alacris (Psyllidae, Hemiptera).  I had previously constructed a key to the 24 species listed as common in the Royal Entomological Society's Handbook to Psylloidea and got in a real mess trying to see the microscopic surface spicules on the wing.  This species didn't appear to have them so I went back to the full key and found it tracked to this species which is listed as locally common.  That is now added to my key and posted at https://sites.google.com/site/mikesinsectkeys/Home/hemiptera/psylloidea