Food metabolic efficiencies of the black blister beetle Meloe proscarabaeus (Coleoptera: Meloidae) as changed by feeding on different host plants

Abstract

The black blister beetle Meloe proscarabaeus is firstly recorded in Egypt during the 1970s and then recorded as an agricultural pest on some crops and vegetables few years ago. The present study aimed to investigate the effects of some host plants, viz. faba bean Vicia faba, Egyptian clover Trifolium alexandrinum, pea Pisum sativum, and lettuce Lactuca sativa, on the food utilization efficiencies in the adults. The appropriate digestibility (AD) through the longevity of adult females and males were determined after feeding on the present host plants. Adult females exhibited the highest AD by feeding on T. alexandrinum but the lowest AD by feeding on P. sativum. The male congeners achieved the highest AD by feeding on V. faba but the lowest AD by feeding on P. sativum. The efficiency of conversion of ingested food into the biomass (ECI) was the highest in both sexes by feeding on T. alexandrinum but the lowest by feeding on P. sativum. The efficiency of conversion of digested food into the biomass (ECD) run in a parallel trend, regardless of the sex. An interrelationship between AD and ECI was appreciated for both sexes. Also, an interrelationship between AD and ECD of females or males was detected since ECD was higher than AD by feeding on V. faba, T. alexandrinum and L. sativa but the reverse was clearly found by feeding on P. sativum. Correlation between assimilation rate (AR), relative metabolic rate (RMR) and relative body weight (RBW) was estimated.