MIXED RISK-SPREADING STRATEGIES AND THE POPULATION-DYNAMICS OF A BRAZILIAN PASTURE PEST, DEOIS-FLAVOPICTA (HOMOPTERA, CERCOPIDAE)

Deois flavopicta (Stal) is a predominant species of grass-feeding spit tlebug in Central Brazil. The climate in this region is a humid/dry cy cle with year-long mild temperatures. We investigated the population d ynamics, diapause, and voltinism of this insect. D. flavopicta has 3 p opulation peaks during the rainy season, and it diapauses in the egg s tage during the dry season. The proportion of offspring entering diapa use varies, with few or no diapausing eggs in the beginning of the rai ny season and up to 100% eggs in diapause by the season end. Diapausin g eggs hatched in 61-360 d. Fifty-two percent of the eggs, however, en d diapause in September and October, the most probable period for the Ist heavy rains of the season. High local populations of D. flavopicta may severely damage a host plant, making it unsuitable for the develo pment of future generations of the insect. Apparently, this species mi grates to other feeding sites when faced with low nutritional quality food.