Parasitism of stink bug eggs (Hemiptera : Pentatomidae) of soybean fields in the Triangulo Mineiro, Minas Gerais, Brazil

A survey of the seasonal occurrence of stink bug egg parasitoids was carrie d out in soybean fields in the Triangulo Mineiro region, Minas Gerais state , Brazil. Collections of egg masses of stink bugs and monitoring of populat ion levels of mobile stages were done weekly during the 1993/94 and 1994/95 soybean seasons. Piezodorus guildinii and Euschistus heros were the most a bundant stink bugs throughout the survey. Rates of parasitism in P. guildin ii eggs ranged from 50.2 to 77% in 1993/94 and from 31.3 to 44.1% in the 19 94/95 soybean season. Parasitism in E. heros eggs ranged from 50.6 to 64.7% in 1993/94 but no parasitized eggs were found in 1994/95. Telenomus podisi was the main parasitoid collected and the only species found to parasitize E. heros eggs. Trissolcus brochymenae and Ooencyrtus sp. were found attack ing P. guildinii eggs, but at low levels. We discuss the contribution of eg g parasitoids to natural control of stink bugs.