An array of spatulate sensilla on the ventral flagellar surface of each antenna of male Brachymeria lasus occurs only on segments IV-VII and is absent on female antennae. Most such sensilla are on segment VI. Each spatulate sensillum was 15 p, by 16.7 p with a stalk extending 17 p, from the antennal base. Pores were not apparent, but the sensillum surface was imbricated. The sensilla are speculated to have a role in the courtship sequence of this chalcid by functioning both as chemoreceptors of the female-produced sex pheromone and as mechanoreceptors to indicate female receptivity, as female B. lasus typically raise the abdomen to expose the genital pocket.
Simser, D. H. and Coppel, H. C.
"An Array of Spatulate Sensilla on Antennae of Male Brachymeria Lasus (Hymenoptera: Chalcididae),"
The Great Lakes Entomologist, vol 24
Available at: https://scholar.valpo.edu/tgle/vol24/iss2/7