Mague, D.L. 1982 . Biology of the San Jose scale (Quadraspidiotus perniciosus (Comstock)) (Homoptera: Diaspididae) in New York apple orchards; male flight phenology .. Cornell University, Ph.D. Thesis Cornell 87 pp.

Notes: [Ph.D. Thesis.] The San Jose scale, Quadraspidiotus perniciosus (Comstock), ranks among the most important insect pests attacking apple (Malus sylvestris Mill.) in New York. Selected aspects of scale biology and control that are important to improved orchard management of this pest were investigated. The seasonal timing and magnitude of male flight were monitored with pheromone traps. The first male flight began in mid-May at from 94 to 140 degree-days above a base of 10 C. This flight frequently coincided with apple bloom and ended prior to 300 degree-days. A second male flight occurred at 667 degree-days and continued through September. Seasonal totals of males per trap were inversely related to scale density on the bark and the percentage of infested fruit per tree at harvest. The seasonal abundance of scale crawlers on the bark was assessed using direct-count samples and electrical tape traps. Two overlapping generations occurred annually, beginning at 360 and 890 degree-days, respectively. Parturition followed mating by an estimated 230 degree-days. The relationship between the number of crawlers sampled per tree and the percentage of infested fruit at harvest was described by the Mitscherlich function. The seasonal abundance of airborne crawlers within and between trees was estimated with aerial plate traps. Seasonal patterns of aerial dispersal activity were highly correlated with crawler densities on the bark. Aerial plate trap catch within trees was highest in the upper canopies of the northeastern and southeastern tree quadrants. The magnitude of crawler aerial dispersal outward from the tree canopy increased with airborne crawler density within the canopy and decreased with distance from the source population. Prebloom treatments with 2% oils and insecticides significantly reduced overwintering scale. The application of oil and insecticides in combination was no more effective than either of these materials used alone. Summer sprays of each of the four most widely used orchard insecticides effectively reduced crop injury from scale. Single sprays applied during both periods of peak crawler emergence gave control comparable to a series of four sprays timed to first and peak emergence of both crawler broods. Insecticides applied at first emergence of each crawler generation were not effective.