Look out for Barkflies!

[Jason Green]

Hi all,

Just a quick note on Barkflies, I thought this may make an interesting thread.

Barkflies are in the Psocoptera order, which comprises of two distinct areas - Indoor booklice which you will often find in kitchen cupboards UK-wide, and Outdoor Barkflies. They are likely to occur in every tree in the UK, and a range of other situations, as below.

Generally speaking, they are very attractive, albeit tiny, flies with often patterened wings. They are found around trees, such as on the bark and some on the leaves. Occasionally you may find them in leaf-litter, on house walls, garden plants, etc. They are often between 1.5mm and 7mm long. Once you've found one, they'll start to stick out more. As the area is fairly under-recorded, even a casual observer has a good chance of finding a rarity! Some are fully winged, others have reduced wings and others are flightless.

Some are active all year, and others start to die out around October. I have found several, at least two species, dead on an old bin under an Ash tree, and consequently you can examine the wings better - the main way of ID'ing most, though sometimes the head may carry markings that may differenciate them from similar Psocids. The highest numbers occur earlier in the summer, but I'm still finding plenty! Finding them may best be done with a magnifying glass, and a macro lens will be advantageous when photographing for ID purposes.

When recording these, take a note of the Grid Ref of where you found it, the habitat such as under an Ash-tree leaf, a house wall, etc., then how you found it - malaise trap, in a moth-trap, brushing a tree down, etc.

Here's a sample Barkfly:

This individual is Blaste quadrimaculata, a rarly-recorded Barkfly that is about 4mm long. I found about three of these in the same area. I rescued this individual from drowning, and found others on a fence.

Feel free to use this thread to post unidentified barkfly photographs, and I'll do my best to help ID them, as will other WAB'ers. Not sure if it is one or not? Post it here anyway! Alternatively send images to the UK Recording Scheme organiser, detailed in the link below. The site also has a key which is wing-based, so good magnification is a huge advantage. My B. quadrimaculata was ID that way.

To submit records, go to National Barkfly (Outdoor Psocoptera) Recording Scheme

Happy hunting!

Take care,

Jason

[Gerel]

Couple of common species to add to your collection Jason,

I keyed this little one, <2mm, out to Ectopsocus petersi



and this one (which I've already posted elsewhere) to Stenopsocus stigmaticus (probably ),



Steve

[Jason Green]

A great shot it is too, Steve. I haven't heard of your second one, so thanks for adding it. I'll try and put in my other ones tomorrow.

[JRsbugs]

I think I had a nymph like your first one Steve, it was in a cup I use for taking insects outside, only around 1mm long!

Janet

[Gerel]

I think nymphs are a bit tricky Janet, at least beyond genus, the key mainly uses wing venation.

I'm not so sure about my ID of the green one now .

I took this close up of the wing and, while the pterostigma definitely seems to widen significantly in the middle (A), a feature of S. stigmaticus, it also has setae along vein Cu2 (B) which is indicative of S. immaculatus.



I think I'm more inclined towards S. immaculatus though.

Steve

[Jason Green]

I've just keyed it out myself and agree - Stenopsocus immaculatus. The setae (I take it that's the word for the tiny hairs?) seem to confirm it. It's nice when you key it all through and get a positive ID at the end of it.

[ChrisR]

Originally Posted by Jason Green

The setae (I take it that's the word for the tiny hairs?)

Setae are actually bristles (e.g. the Setaceous Hebrew Character moth is supposed to be bristly ... but not sure which part is bristly!) and you have to be quite careful in the study of Diptera about what constitutes a bristle or a hair

In my field (Tachinidae) bristles are obviously thicker than hairs and often have a socket at their base. Hairs are much thinner and won't have a socket or leave any noticeable mark on the body when removed.

[JRsbugs]

Good description Chris, I wonder if men's whiskers would be classed as setae! ouch!

I've uploaded my nymph pics, 3 the same but showing all as one might show something the others don't. The wings are half way or more developed, you can make out some detail. This was at the bottom of one of those deep plastic soup cartons, ideal!

Also two others similar, taken a day apart with an adult and a young nymph. These are not the usual ones I have, although I have found a few different I think.

There is one which I have had quite a few nymphs of, the first pair of adults I found in the kitchen and a few times after outside look to be the parents but there could have been more than one lot of parents. I'll address those another time!

You'll find only one pic in the unidentified insects section, I forgot to select then only did one!

[JRsbugs]

Hey Jason!!! Hey hey hey, lol! I've been searching for one of my Barkflies, found yours on the Psocoptera site of Blaste quadrimaculata and I thought mine was very close if not the same.

Then on a google I came across this link, so took a look at your pic here again and I can see more of the back and face than the other pics. I'm sure I have it too!!!!!! My pic is a little distant as it was running up the wall, not what you usually see them doing but they do live on walls and it's an old lime mortar wall!!! 2nd July which is the right time too!!

Will post the pics tomorrow/today.