Life History and Natural Enemies of Parthenolecanium spp. in Four Southeastern States

Soft scales (Hemiptera: Coccidae) are some of the most prevalent and difficult to control arthropod pests in urban landscapes of the southern United States. European fruit lecanium, Parthenolecanium corni (Bouche), and oak lecanium, Parthenolecanium quercifex (Fitch), are commonly found in mixed populations as pests of oak trees (Quercus spp.) in the region. The phenology and natural enemies of the two species are poorly understood, which in turn hinders pest managers\u27 ability to develop an integrated management program against these species. This research project aims to fill the information gaps concerning the life history and natural enemies of P. corni and P. quercifex. The first study sought to better understand the life history of P. corni and P. quercifex in South Carolina, and to develop predictive models (based on degree-day and plant phenological indicators) for crawler emergence in Georgia, North Carolina, South Carolina and Virginia. The scale insects were found to be univoltine. Eggs hatched between mid-April and early June, second instars began to occur in October, and third instars and adults in mid-March to early April. Each parthenogenetic female produced 177 to 2,398 eggs. Fecundity was found to be proportional to weight of females (including eggs) and body length, width and height