Effects of larval crowding on some biological characteristics of the blowfly, Calliphora vicina (Robineau-Desvoidy, 1830) (Diptera: Calliphoridae)

Abstract

Blowflies are well known necrophagous insects and usually the first insects to discover and colonize a body after death. Thus, postmortem interval (PMI) can be estimated from the length or stage of development of blowfly larvae collected from a corpse. Abiotic and biotic factors influence multiple traits of a population, including body size, fecundity, survival and development rate. Larval crowding is one of the factors affecting blowfly population dynamics. The purpose of this study was to analyze the effect of larval mass on some life history parameters of Calliphora vicina (Robineau-Desvoidy, 1830) (Diptera: Calliphoridae). Experiments were conducted at the Animal Physiology Research Laboratory, Ondokuz Mayis University during 2017. Five, 25, 50, 100, 500 or 1000 newly hatched C. vicina larvae were introduced into a plastic cup containing fresh chicken liver and kept at 22 degrees C and 70% RH under a 12:12 h L:D photoperiod. They were checked at 12-h intervals and development period, survival rate, adult eclosion time, sex ratio, adult size and pupal and adult weights were recorded. The development periods for larval and pupal stages were positively affected by larval crowding. However, larval and pupal survival rate and the percentage of individuals reaching adulthood were very low in the crowded groups. The results also indicated that pupal and adult weight and adult size negatively affected by increasing larval density. It is concluded that larval crowding has an important effect on life history parameters of C. vicina and this need to be considered more reliable estimation of PMI.