Bonjour Eugène.
Voici la réponse de Simon HAARDER:
Dear Jean-Michel Garel,
Yes, it is - most likely - Cupressatia siskiyou (Felt, 1917) from overall appearance and the host you collected it on. But to be sure specimens should be examined. I think your specimen is a male (hard to see from the photo) and male
genitalia are best for correct identification.
If you wish, you could collect the cones of Chamaecyparis lawsoniana and place them in a small container with a few (small!) holes in the top. The adult midges will soon appear, and most likely also associated parasitoid wasps! Two species are known to parasitize C. siskiyou:
Torymus janetiellae:
https://www.naturbasen.dk/observation/1 ... anetiellae
Aprostocetus craneiobiae:
https://www.naturbasen.dk/observation/1 ... raneiobiae
None of these species are recorded from France, so this would be interesting! I have reared these species from material collected in Denmark, Sweden and Poland, so most likely they will occur in France, too. Cupressatia siskiyou has been recorded from three localities in France (two in the south, one in the north) according to the paper "Gall Midges of France" (Skuhrava et al. 2005), but maybe more records have been submitted to online databases since then.
