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Dear all

I was wondering if this fly is most commonly found singly or if it is encountered in large groups? The reason I ask is that I found a nest of the sphecid, Crossocerus megacephalus, where the female had provisioned the brood cells with this fly. There was only one active brood cell in the nest as the other larvae had completed their development, but this cell alone contained 15 C. asiliformis. The nest contained three brood cells in total suggesting the female wasp had collected around 40-50 individuals of this fly.

I am not sure if this wasp is a specialist on this fly or if the female sphecid in question just happened to locate a local abundance of this species.

Any insights appreciated.

Ross


http://scrubmunch...press.com/

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AFAIK they do not aggregate but occasionally you can find many specimens scattered in a smaller area. Knowing how good sphecid wasp are in visual oreintation I wiould not be surpirsed if the are also very good at singling out one particular species as victims when the occasion arrises.

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Thanks, Paul.