Dry-season embryonic dormancy in Deois flavopicta (Homoptera : Cercopidae): Roles of temperature and moisture in nature

A field-based experimental study examined the roles of temperature and mois ture in the dry-season embryonic dormancy and postdormancy hatching of tile spittlebug Devis flavopicta Stal from Brazil's dry interior region. The re sults show that dormancy consists of two discrete parts: an initial period of diapause that persists from April to the beginning of July, followed by a period of postdiapause quiescence that prevails until the rainy season be gins (usually October). Low temperatures during the early part of the diapa use period accelerates diapause development, whereas contact with liquid wa ter determines the timing of postdiapause hatching. Soil temperatures durin g June and July and the relative humidity of the soil during August and Sep tember strongly affect overwintering survival and thus are important in det ermining the size of the nymphal population after dormancy. The findings in dicate that, like hibernation and aestivation in temperate-zone insects, dr y-season dormancy in tropical insects is a dynamic state that is influenced by seasonal changes in key environmental factors.