Tumminelli, R., Conti, F., Saraceno, F., Raciti, E., & Schilirò, E. 1996 Seasonal development of California red scale (Homoptera: Diaspididae) and Aphytis melinus De Bach (Hymenoptera: Aphelinidae) on citrus in eastern Sicily.. Proceedings of the International Society of Citriculture I: 493-503.

Notes: [VIII International Citrus Congress, 12-17 May 1996, Sun City, South Africa.] During the period of 1993-95 in eastern Sicily groves, catches of overwintering, first and third generation males of Aonidiella aurantii, usually showed well-defined peaks. Anomalous peaks were recorded for the second generation captures that sometimes overlapped with first generation catches. This effect was attributed to heat, which could also be the reason why only two Aphytis melinus capture periods were recorded: the first in February-May and the second in September-November. In general the occurrence of A. aurantii peaks could be predicted by degree-day accumulation, using the lower development threshold (t = 12 degrees C) and the thermal constan (K = 600 DD). The average thermal constant of the four main peaks (overwintering, first, second and third generations) was 602.7 DD (+/- 59.2). A. aurantii and A. melinus catches, degree-day accumulation as well as fruit monitoring, best determined the economic threshold and timing for sprays or augmentative releases for the integrated control of A. aurantii.