Posted by Rui Andrade on 17-11-2022 01:00
#1
Hi,
I post this photo at the request of Michael von Tschirnhaus.
location: Gondomar (Portugal)
date: 30/05/2021
Edited by Rui Andrade on 20-11-2022 23:52
Posted by von Tschirnhaus on 17-11-2022 16:47
#2
Chloropidae, Chloropinae: Cetema elongatum (Meigen, 1830) or C. neglectum Tonnoir, 1921, female. Both sympatrical species with dark arista develop in species of different grass genera (Poaceae). Females are difficult to distinguish as only the males of T. neglectum possess long hairs on fore- and mid-tibiae. By studying long series of both species from different countries I found out two features helpful to distinguish females, too. The postvertical setae of C. elongatum stand behind each ocellus or slightly outside (widely separated), while those of neglectum are close together behind an inside the pair of ocelli. Moreover the hairs on the lateral side of the abdomen are dark in elongatum and light in neglectum. In the nice photograph the two indistinct light points behind the ocelli speak for elongatum. Cetema [Greek] is a neuter noun.