As it turns out, the plastic flies they had were pretty much perfect and I bought a full unit's worth for $5. To bulk them up a little and give someplace to put the brass rod I added some black milliput to the abdominal cavity. The paint job is mostly Nurgling Green drybrushing, with some of a lighter green too (the name of which I can't remember.) Tamiya clear yellow (thank you, Javi!) was used to tint the wings. The eyes are Vallejo air color silver (my single favorite brush on silver of all time) with a coat of Tamiya clear yellow over it, then a green wash on the bottom half of the eyes. The legs are not changed.
A base, a little cork and some Vallejo plastic putty snow later we have a full unit of these pretties.