Dr. Papp Jenő szerk.: Folia Entomologica Hungarica 25/1-7. (Budapest, 1972)

New etiological observations on Quadraspidiotus perniciosus Comst. (Horn., Coccoidea) By F. Kozár Plant Protection Station of Veszprém County, Csopak The first European record on San Jose scale was published in 1935 in Hungary. This pest is perhaps the one which caused the most consternation in the past decades for the practical experts dealing with entomology. Our etiological studies began in 1967 and lasted for some four years in Veszprém County /Western Hungary/. In the course of our investigations we carefully studied the swarming of males, the number of offsprings, the effect of the different geographical places on swarming, the degree of destruction during winter and the development of the ratio of male and female feeding on the various parts of the plant. We have established that the mortality of the overwintering form of San Jose scale is 6-61%. The male swarming of the first generation requires some 11-14 days. The beginning of the swarming of males shows a tolerance of 7 days but the same for males living on the different parts of the plant may even display a tolerance of 9-15 days. The first generation of swarming larvae may show a tolerance of 19 days, while that of the second 15 days.Between the beginning of the swarming of males and that of the first generation larvae a difference of 31-34 days occurs, while in the case of the second generation we observed a difference of 22-36 days. The swarming of males of the third generation begins in the middle of October. The swarming of the first generation males proceeds by 1-2 weeks the full blooming of apple-trees.