Adult carrion fly (Diptera: Calliphoridae) visitation patterns by time of day at sunlit versus shaded pig carrion in southwestern West Virginia, USA.

Abstract

A study to determine adult visitation patterns of two forensically important carrion flies (Diptera: Calliphoridae), Phormia regina (Meigen) and Lucilia (= Phaenecia) coeruleiviridis Macquart, was conducted at a wildlife management area in southwestern West Virginia. Pig carcasses (Sus scrofa L.) were used as surrogates for human bodies in sunlit vs. shaded field plots in four separate experimental periods; May of 2006, 2007 and 2008, and June of 2008. Aerial collection samples revealed that the proportion of P. regina was greater at sunlit carcasses than shaded ones, whereas the reverse was true for L. coeruleiviridis. Phormia regina adults, either alone or co-occurring with L. coeruleiviridis, were the first to arrive at sunlit carcasses, but L. coeruleiviridis consistently made up the “first arrivals” at shaded carcasses. Both species were most frequently collected at 2:00 p.m. and least likely to be collected at 8:00 a.m. on sunlit carcasses for all experimental periods. At shaded carcasses both species were least likely collected at 8:00 a.m., but P. regina and L. coeruleiviridis were most commonly collected at 2:00p.m. and 8:00 p.m., respectively. Sex ratios for both carrion fly species were decidedly female-biased in sunlit and shaded conditions.