Studies on the morphology and systematics of scale insects. No. 16, Biosystematics of the family Dactylopiidae (Homoptera Coccinea) with emphasis on the life cycle of Dactylopius coccus Costa

The cochineal insects include nine species assigned to the genus Dactylopius, the only genus in the family Dactylopiidae. This is a review of all the species in the family Dactylopiidae, with special emphasis on the life cycle of the type species Dactylopius coccus Costa. The adult females of the nine species have been redescribed and illustrated, with a discussion on their morphological affinities and relationships. Their hosts, natural enemies, distribution, etymology, and role as biological control agents are discussed. For several species many new distribution and host records are given. Also, new types have been designated for the following species: one neotype and three paratypes for Dactylopius coccus Costa; one neotype for D. tomentosus (Lamarck); and designation of eight new topotypes for D. opuntiae (Cockerell).

Methods are given on collecting, preservation, slide mounting, measuring, and preparing illustrations. Cuticular ultrastructure is shown in scanning electron micrographs. All developmental stages of the type species, D. coccus, are described. The life cycles under two temperatures and two relative humidities, for both males and females, are discussed. Aspects of reproduction in D. coccus, its dispersal methods, factors affecting development, and its economic importance are also included.

A separate chapter deals with the host-plants of Dactylopiidae. This chapter includes data on host plant suitability and host plant resistance. Three identification keys are presented: one to the suborders of Homoptera, the other to the superfamilies and families of Coccinea, and another one for the determination of the species of Dactylopius. The phylogenetic relationships of the family Dactylopiidae with respect to all the Coccinea families are discussed, and a phylogenetic tree for the Dactylopius species is proposed.