Bionomics of the Crapemyrtle Aphid (Homoptera: Aphididae)2

Abstract

Populations of the crapemyrtle aphid, Tinocallis kahawaluokalani (Kirkaldy), in South Carolina develop from overwintering eggs which are distributed near new emerging leaves. Seasonal abundance is typically bimodal and locally concurrent within a season, but without consistency in timing or intensity of occurrence between seasons or host plant cultivars. On leaves of Lagerstoemia indica L. (‘Carolina Beauty’ [CB]) in the laboratory, time of development was temperature-dependent, requiring 14 d for development through four instars to the adult at 18° C, 6 d at 26° C, and 5 d at 32° C. Longevity of adult virginoparae was ca. 17 d, 13 d, and 8 d, at these temperatures, respectively, and was at least as long on leaves of the apparently less susceptible ‘Natchez’ (N) cultivar. Fecundity was greatest at 18° and 26° C, averaging 56 and 61 offspring/female, respectively, on CB leaves and 54 and 71 offspring/female on N leaves. Fecundity declined sharply to 27 and 18 offspring/female on CB and N, respectively, at 32° C. Maximum daily fecundity rates were attained within 5 d of adult reproductive age on both host cultivars, then declined at temperature-dependent rates. Male and female sexuales were produced in early fall as mixed progeny with sexuparae at a ratio of 12.2: 9.7: 3.5 sexuparae: oviparae: males. Longevity of males was 7 d; oviparae lived 8 d and produced 1 to 6 eggs each. Syrphids and coccinellids were principle components of the predator complex associated with dynamics in the crapemyrtle aphid populations. Population dynamics in the absence of predators was characterized by a maximum density of ca. 200 aphids/leaf on CB attainable within 5 wk of inoculation with a single aphid followed by a sharp decline. Population development potential decreased as the season progressed. A braconid, Lysiphlebus testaceipes (Cresson) (Hymenoptera: Braconidae), reared from mummies of the crapemyrtle aphid in a greenhouse, constitutes the first reported parasitoid.