Morphological and biological studies on two species of Chionaspis (Homoptera: Coccoidea: Diaspididae)

Abstract

Morphological studies in the past have been almost exclusively confined to the description and illustration of adult females. Morphological studies of Diaspididae were further restricted to the pygidial area. This study is an attempt to provide complete descriptions, illustrations, and measurements for morphological characters for all life stages of C. americana Johnson and C. kosztarabi Takagi and Kawai.

The majority of the specimens were obtained from weekly collections of local infestations on the Virginia Polytechnic Institute and State University campus. Freshly collected scale insect samples were mounted in both Hoyer's medium and Canada balsam for microscopic study.

The biologies of the two species in Blacksburg, Virginia were studied using weekly collections. Both species were bivoltine. C. americana overwintered mainly in the egg stage; the first brood hatched about April 20, and the second brood about July 25, in 1972. C. kosztarabi overwintered as fertilized females. Eggs were laid in early spring hatching about May 28 in 1973, and the eggs of the second generation began hatching about August 10, in 1972. Dimorphic males of both species were collected. C. americana males exhibited apterous and brachypterous conditions. C. kosztarabi males were either apterous or pterous. Several species of hymenopterous parasites were reared from each species.