Biology, seasonal distribution of stable flies, Stomoxys spp. (Diptera: Muscidae) and Fly-repelling behaviors of beef cattle

Abstract

The study on life cycle of stable fly, Stomoxys calcitrans (L.) was conducted at 25+1oC, 76-84% R.H. The entire life-cycle from egg to adult was 30.79+4.38 days. An incubation period of egg was 2.60+0.71 days. Larval period, pupal period, and longevity of female and male were 8.70+1.18 days, 5.80+0.70 days, 11.43+4.35 days and 15.95+4.26 days, respectively. Population of stable flies was monitored by counting the fly on front legs of beef calf and from sweep net. To count the fly during feeding on front legs of beef calf, a 12 x 2 factorial experiment in completely randomized design (CRD) was applied with 4 replications of one-year-old beef calves (native hybrid x Brahman) in individual pen. Fly counts were made weekly, twice per day per week at 11:00 a.m. and 03:00 p.m. for one year. The results showed the peak of 8.63 stable flies per day in May, fly populations during May-October, except in August, showed significantly different to those population during November-April (P<0.01). The number of flies at 03:00 p.m. was significantly higher than those at 11:00 a.m. (P<0.01). The peak of stable flies catched from sweep net was 19 individuals in April, 2008. The observation of stable fly-repelling behaviors of beef calf for 5 months from June to October, 2006 showed that tail flicks and skin twitches were dominant behavior followed by front leg stamps and head throws. Tail flicks and skin twitches were not significantly different. The frequencies of dominant behaviors in June was significantly higher (30.49%) than those of other months.