Thursday, January 30, 2020

Children of a Lesser Dungfly - the ice cream tub bait trap and the lesser dung flies

One family that's doing very well on the 2020 records is the Sphaeroceridae, or lesser dung flies. So far five species have been identified (and two not!). This is a family I have an emotional tie to (yes, really) because it was one of the first monographs (Pitkin, RES) I acquired when I moved out from hoverflies.

Sphaeroceridae
Copromyza nigrina - fish-baited trap
Crumomyia fimetaria - leaf litter
Crumomyia nitida - fish-baited trap
Crumomyia roserii - fish-baited trap
Lotophila atra - leaf litter

Sieving leaf litter is always a good way to pick up a sphaerocerid or two, but a ground-level bait trap seems like a definite winner. The elevated bottle traps don't seem to catch them - I think because these flies mostly don't get very far away from the ground. This is also a good way to pick up Heleomyzidae, of which 3 species have been found in this session using this trap . One of the species was also found in the elevated bottle trap, but all three were in the low-level trap. The trap is jammed up against a ruined wall so it's probably warmer and more sheltered down there too.

Heleomyzidae
Neoleria propinqua
Scoliocentra villosa
Suillia variegata (in leaf litter, not in trap)
Tephrochlamys rufiventris

The trap design
I took an ice cream tub and cut a cross hole in the lid. The cardboard disc "filter" lets out the stink but stops things falling into the gooey mess that once was sea bass. The disc has lobes that stabilise it but I didn't draw them. Drainage holes are also not illustrated. Any sort of tub and cereal packet could be put into service this way and is essentially recycle-able. An occasional fly has flown away but once in the trap the dung flies and heleomyzids seem more-or-less happy to sit around and be potted.

Ice cream tub, fish remnants, cardboard disc

Apart from the flies this trap has yielded about 100 Catops beetles, the only one of which I gen-detted being C.tristis. And boy does it make them crazy - lots of mating pairs. I suspect there may be more than one species of Catops present. Sadly none I've taken have shown signs of fungal infection.

A modified version of this trap (larger entrance) is going to be great for silphids at some point and changing the bait up might make it a winner for dung beetles too.

NB: I always approach this trap wearing rubber gloves!

(12/02 edit: the actual tub, which has now been in place for just over a month)


Tuesday, January 28, 2020

Monday, January 27, 2020

Finding beetles in January - blog link

Worth a read if you haven't already:

http://www.northwestinvertebrates.org.uk/hunting-beetles-in-winter-chester-meadows/?fbclid=IwAR1Xf3y3K8o_Nx5P7LuU51LcQTVh27sxaRHN120OBvWef6yii_EdKnNgcco

Rot hole rat-tails

While wandering across a little-visited area of my new patch (Cullaloe Hills, NT1888) I noticed a rot-hole in a sycamore. Fortunately I was sporting gardening gloves for leaf litter sieving and a cursory dip revealed a nice Myathropa florea larva. A further investigation later revealed two more, but nothing additional.




Monday, January 20, 2020

Lonchaea patens, Cullaloe Hills, NT1888, 12.i.2020

A larva found in a wet pocket of felled Fraxinus trunk on the 12th January, which I initially planned to rear out. However, since I had already examined another lonchaeid larva I decided to compare this one. This one was much easier to determine with the RES Lonchaeidae book, though the other one may also give itself up eventually.

Habitus

Posterior spiracles

Head skeleton and toroidal mouthhooks




Anterior spiracle post KOH application

Various spicules, including anal (bottomlright)

Where it was found


Thursday, January 9, 2020

Crumomyia roserii in the Cullaloe Hills

Caught at a fish-baited trap, this little lesser dung fly has yellow-brown tibiae as an "obvious" feature

infuscated wings

yellow tibia

pleural dusting pattern is helpful in ID

Tuesday, January 7, 2020

Juncus bulbosus (Bulbous Rush) and Lophocolea semiteres in the Cullaloe Hills

The plant from which last post's bug was taken, this was growing in the ditch beside the path under the mossy embankment


The liverwort Lophocolea semiteres was also not far off th epath, growing principally at the base of a large conifer. It appears to be new to the county (edit: confirmed). This is the male plant below, but female plants were also there.


Monday, January 6, 2020

Acalypta parvula from Cullaloe Hills

Spotted under the microscope on a specimen of Bulbous Rush, this very small bug is a moss lover which overwinters as an adult