Forecasting Flight Activity of Native Parasitoids of Oak Lecanium (Homoptera: Coccidae)

Flight activity of the major parasitoids of oak lecanium scale, Parthenolecanium quercifex (Fitch) was monitored for 6 years on willow oak, Quercus phellos L. to establish base development temperatures and to forecast peak parasite activity. Base development temperatures of 8.3°C (47°F), 10.6°C (51°F), and 3.3°C (38°F) were established for Encyrtus fuscus L., Eunotus lividus Ashmead, and Blastothrix sp., repectively. Average degree day accumulations indicated that flight periods for all species occurred during early June, a time when pesticides are usually directed against the first instar scales. An early flight period of E. lividus also coincided with pesticide applications against two oak defoliators, Lyrnantria dispar (L.) and Malacosoma disstria Hübner.