Mixed risk-spreading strategies and the population dynamics of a Brazilian pasture pest, Deois flavopicta (Homoptera: Cercopidae).
1995
Fontes E.G. | Pires C.S.S. | Sujii E.R.
Deois flavopicta (Stal) is a predominant species of grass-feeding spittlebug in Central Brazil. The climate in this region is a humid/dry cycle with year-long mild temperatures. We investigated the population dynamics, diapause, and voltinism of this insect. D. flavopicta has 3 population peaks during the rainy season, and it diapauses in the egg stage during the dry season. The proportion of offspring entering diapause varies, with few or no diapausing eggs in the beginning of the rainy season and up to 100% eggs in diapause by the season end. Diapausing eggs hatched in 61-360 d. Fifty-two percent of the eggs, however end diapause in September and October, the most probable period for the 1st heavy rains of the season. High local populations of D. flavopicta may severely damage a host plant, making it unsuitable for the development of future generations of the insect. Apparently, this species migrates to other feeding sites when faced with low nutritional quality food.
显示更多 [+] 显示较少 [-]