Posted by Stephen on 28-01-2021 15:47
#1
Terrible small photos, but maybe someone will recognize the behavior.
These flies were numerous around some gregarious sand wasps (Crabronidae: Bembicinae), and entered their holes when the wasps were not present. The wasps were, I believe, Stictia signata.
Any thoughts about the family of fly?
U.S. Virgin Islands (St. Croix), sandy beach about 15 meters from the ocean beach. Sand with patchy grass.
I believe (by memory) the flies were about 3-4 mm long.
Edited by Stephen on 28-01-2021 15:50
Posted by Stephen on 28-01-2021 15:48
#2
Another photo, showing the entrance to the wasp burrow.
Posted by Xylosoma on 28-01-2021 16:00
#3
Hi, my first thought was Chloropidae. And indeed, it seems that your picture fits well to Liohippelates known as cleptoparasitic on Stictia signata.
Regards
Xylo
Edited by Xylosoma on 28-01-2021 16:03
Posted by Stephen on 29-01-2021 18:31
#4
Thanks, Xylo. Looking further into my files, I found a better photo and notes that the length was 2.2 mm to the wing apex.
Edited by Stephen on 29-01-2021 18:31