ooohhh......so nice, There are various literature(s) dealing the DDT selection of laboratory bred sand flies. You can follow the under noted references.
Also, expecting varied content of DDT accumulation in different population of an insect specie is quit an interesting job. You can proceed for the insecticidal exposure in that way following to the separating male and female insects individually.
Hi Leila, I have been trying to select for permethrin and malathion resistance in P. papatasi for a few years now. It has been very difficult to drive resistance into our laboratory populations. For my populations, I don't differentiate between males and females; they all get exposed to the insecticide. Saul is right, though, that there is probably differences between sexes. Saeidi et al. 2012 looked at differences between male and female P. papatasi "Baseline susceptibility of a wild strain of Phlebotomus papatasi (Diptera: Psychodidae) to DDT and pyrethroids in an endemic focus of zoonotic cutaneous leishmaniasis in Iran"
I have done DDT for selection of phlebotomine sand fly in laboratory and got a satisfactory result as dealt in our forthcoming publication, but the things has been observed in case of P. argentipes an Indian VL vector specie. Hope it may help you take significant lead in this way.
@Aarti, I can't wait for your publication on DDT-selection. I'm close too to submitting research on pyrethroid and organophosphate artificial selection in P. papatasi