Proximity to parasites reduces host fitness independent of infection in a Drosophila-Macrocheles system

We assayed the longevity and reproductive output of Drosophila nigrospiracula exposed or not exposed to ectoparasitic Macrocheles subbadius accross a mesh barrier. As such we measured the non-consumptive effects (extending the ecology of fear to host-parasite systems) of an ectoparasite on host fecundity and survival. We found that exposure to mites, without infection, caused flies to live shorter lives and produce fewer offspring.

Methods
Experimental female flies were held in vials with either 1) a male fly (mated groups) or 2) a companion female (unmated groups - the companion fly had a wing clipped to distinguish them from the experimental fly.

Flies were moved to new vials every 3 or 4 days, replacing the companion as needed. Flies were checked for survival every 24 hours.

Exp 1: Flies were held on agar vials and only survival was measured.

Exp 2: Flies were held on a drosophila media-potato-cactus blend and the vials were retained after experimental flies died/were moved. Vials were retained for 2 weeks and the number of offspring (adult offspring + pupae) was calculated for each fly.