Taxonomy of the Bruchidae*(Coleoptera) of Northwest India. Part I. Adults

Abstract

Forty-eight species of bruchids have been collected from different localities in Northwest India during 1964-1969. Out of these, 23 species belong to Bruchidius, 8 to Caryedon, 5 to Callosobruchus, 4 to Spermophagus, 2 each to Bruchus, Conicobruchus and to Specularius and 1 each to Zabrotes and Sulcobruchus. As many as 13 species are associated with edible seeds whereas the remaining 35 species attack the seeds and the pods of the wild forest, medicinal or ornamental plants of the families Compositae, Malvaceae, Convolvulaceae, Anacardiaceae, Palmae, Rosaceae, Umbelliferae and Papaveraceac.The different species show a variable degree of host specificity ranging from the species which attack only a single host plant to the ones which are capable of breeding on several host plants. Then there are some which remain confined to the hilly areas whereas there are others met with only in the plains over wide areas having different climatic conditions.The genera Bruchus, Bruchidius, Sulcobruchus, Conicobruchus and Specularius are univoltine and attack the green pods of wild plants; Spermophagus is univoltine associated with both edible and non-edible host plants whereas Callosobruchus and Zabrotes are multivoltine and restrict their attack to stored edible pulses. Caryedon, however, is exclusive in starting the attack in the field but continuing to breed on the dry seeds of the its host plants.Some species belonging particularly to Bruchidius and Spermophagus have been collected from flowers, rolled leaves and empty and semi-dehisced pods of plants, presumably their transitional host plants because they do not breed in them; their primary host plants are not known.Sexual dimorphism is common in Bruchids. Sexual differences usually relate to the structure and the length of the antennae, the armature of the femur and the tibia, the colour pattern on the elytra and pygidia, and the shape of the last visible abdominal sternite.The processes of copulation and oviposition are more or less similar in the different species but the duration of copulation shows a marked variation and ranges from less than a minute to about thirty minutes, depending on the form and the length of the male genitalia.The normal and the abnormal (sterile) males of Callosobruchus maculatus can be separated easily on the basis of the colour patterns of their elytra and pygidia, and the structure of the male genitalia. The details of these structures have already been published.A trichogrammatid parasite, Uscana sp., parasitizing the eggs of Callosobruchus maculatus and C. analis has already been noticed.Of the 48 species so far collected, 25 appear to be new. The species have been described in detail and the descriptions include the structure of the genitialia. In the preparation of keys to the subfamilies, genera and species, particular emphasis has been laid on the structure of male genitalia in addition to other important morphological characters.