Roles of fresh and decomposed liver on aspects of reproduction of blowfly Chrysomya chloropyga (wied.) (Diptera: Calliphoridae)

Abstract

This study compared the effects of fresh and decomposed liver on aspects of reproduction of the blowfly, Chrysomya chloropyga to determine the possibility of multiple generations of the blowfly on a single cadaver. The total development time from egg to adult were 8.75 and 8.50 days in the flies fed on fresh and decomposed liver respectively and were not significantly different (p=0.58) from each other. The sex ratio (male: female) was 1:1 on both diets. There was a significant difference in the survival of adults fed fresh and decomposed liver (p=0.001, 0.001). There was no significant difference (p=0.362, 0.029) in the longevity of flies fed fresh and decomposed liver. Age at first egg laying on fresh and decomposed liver were 15.00 and 7.25 days respectively on fresh and decomposed liver. Fecundity of 175.6 eggs recorded in the flies fed on fresh liver was not significantly different (p=0.804) from that (200.8 eggs) of flies on decomposed liver. Mean weights of male and female flies maintained on both diet increased from the first day to tenth day only. However, it was not significantly different (p=0.130, 0.576) from each other throughout the period of exposure. Protein concentration was significantly higher in females fed fresh liver than those maintained on decomposed liver at ages 0 to 25 days. In conclusion, decomposed liver was as effective as fresh liver in supporting reproduction of the C. chloropyga with a better performance on decomposed liver. The study also demonstrated a strong indication for more than one generation of flies on a sizeable cadaver.

Key Words: Blowfly, Chrysomya, Decomposition, Forensic entomology, Reproduction