Interaction effects of temperature and food on the development of forensically important fly, Megaselia scalaris (Loew) (Diptera: Phoridae)

Abstract

In forensic entomology, breeding of fly larvae in a controlled laboratory environment using animal tissue is a common technique to obtain insect developmental time for the estimation of postmortem interval. Previous studies on growth media are mostly on the effect of different diets on fly development. However, the interaction effects between temperature and food type used have not been explored. The objective of this study was to compare the use of cow's liver agar and raw liver on the development of a forensically important fly, Megaselia scalaris (Loew). This study also determined the interaction between different temperatures and different food types on the growth of this species. A total of 100 M. scalaris eggs were transferred into each of the two media mentioned above. Liver agar was prepared by adding dried ground liver into nutrient agar, whilst raw liver was naturally prepared from the same animal source. This experiment was conducted at 27, 30 and 33 °C in an incubator in a continuously dark condition. Length and weight of larvae, puparia and adult samples were determined. Total developmental times for larvae feeding on liver agar at each temperature were approximately 7-15 h slower than those feeding on raw liver. Survival rates were almost equal in both diets but were lower at 33 °C. Mean larva length in both diets did not differ significantly at all temperatures, but larvae feeding on liver agar had lower mean weight values than those in raw liver at 30 and 33 °C. The effect of temperature was significant in female puparia weight and male adult weight whereas the effect of diet types was significant in both male and female puparia size and weight. Interaction effects of temperature and food type on M. scalaris puparium size and adult weight were significant, indicating that puparium size and adult weight depended on both food type and temperature. This experiment highlighted the use of cow's liver agar as an alternative diet to breed M. scalaris in the laboratory and the importance of considering the interaction effect between temperatures and food types when deciding the most suitable medium in fly larva rearing.

Growth and development of Chrysomya saffranea (Diptera: Calliphoridae) in response to different food substrates

“…The degree of the effect of the correlation between temperature and food on Megaselia scalaris (Phoridae) was also studied (Zuha et al . 2012).…”

Formulation and evaluation of the efficacy of an artificial diet for two forensically-important flies

“…The findings were likely that the 1 st instar, 2 nd instar and 3 rd instar took 1-2, 1-2 and 3-4 days consecutively and a more 1-2 days were needed before pupation when the flies were exposed at 22-24°C. Different diets have different effects on M. scalaris regarding developmental time and size as well as adult emergence and longevity (Idris et al, 2001;Zuha et al, 2012). This is one of the reasons, we prepared a standard diet on which M. scalaris can easily be reared for research and many more works related to forensic entomology.…”

Rearing the scuttle flyMegaselia scalaris(Diptera: Phoridae) on industrial compounds: implications on size and lifespan

“…Megaselia scalaris diets influence the development of larvae and pupae both in terms of developmental time and size, as well as adult emergence and longevity (Idris, Abdullah & Lin, 2001; Harrison & Cooper, 2003; Zuha et al, 2012). The difference in pupal and adult size we observe is likely due to reduced nutrient content of modeling clay when compared to standard food.…”