Two new species and additional collection records for the genus Protodiaspis (Homoptera: Coccoidea: Diaspididae)

Abstract does not appear. First page follows.

Introduction

The genus Protodiaspis is probably native to the Western Hemisphere, where it occurs almost exclusively on oaks. The genus includes a somewhat larger number of species than the average diaspidid genus of North America. (Ferris (1937))4 questioned the homogeneity of Protodiaspis but did not attempt to subdivide it. The genus is of special interest because the females are incompletely pupillarial; the molt of the second instar does not quite cover the adult female, which may also possess a rudimentary or woolly scale. The morphological diversity within the genus seems, however, to be simply due to increasing adaptation to the pupillarial type of existence (Brown and McKenzie, 1962), the second paper in this issue).

In addition to the evolutionary trends within the genus itself, forms similar to it may have been ancestral either to completely pupillarial types, or to forms with little or no covering; these possibilities have been further considered in relation to the chromosomal systems of the Diaspididae by Brown and McKenzie in the paper just cited. Many of the species of Protodiaspis are native to Mexico, where the oak forests are being destroyed to open land for cultivation. In view of the central position which Protodiaspis holds in current concepts of the evolution of the armored scales, it is to be hoped that entomologists will continue to collect it whenever possible.

Descriptions of Two New Species

One new species of Protodiaspis is described from Guatemala and the other from Arizona. Both show close relationship to other components of the genus, and thus provide further examples of evolutionary change in the group. Determination of the chromosome system and numbers in the first-described species not only aids in its proper identification, but also contributes to our understanding of the evolutionary sequence of these Coccoidea.