The effect of temperature, rainfall and relative humidity on the seasonal fluctuation of Dermatobia hominis was investigated by counting the parasitized skins of slaughtered cattle at the abattoir of Pirai county, in the state of Rio de Janeiro, Brazil, from November 1995 to October 1997. The higher incidence of parasitized skins was observed in November 1995 and December 1996. Secondary peaks were observed in March and May 1996 and March 1997. High percentage of parasitism in skins through the summer seasons was associated with mean temperatures of 25°C and rainfall of 200 mm. The larval populations declined in both years from June to October, probably due to low temperatures at an average between 21ºC and 22.5ºC, and to low rainfall (under 50 mm). In a total of 5,142 skins checked in the 2-year study, 2,710 skins (52.7%) were parasitized with D. hominis larvae.
Dermatobia hominis; seazonal fluctuation; bovine skin
