Some aspects of biosystematics of Bruchidae (Coleoptera)

Abstract

Bruchidae forms a small compact group of phytophagous Coleoptera with well defined ecological limits. Its members are by and large seed eaters, mostly attacking the seeds of Leguminosae including edible legumes. Several genera show definite host plant relationships and many species present strict host specificity. The bruchids of economic importance fall into two categories viz (i) store bruchids and (ii) field bruchids, with separate voltinism and distinct pattern of development. The bruchids of no recognized economic importance also have characteristic host plant relationship, pattern of distribution and avoidance of interspecific competition. Apart from the known taxonomic discrimination on the basis of external morphology, the genera and species can also be characterized from variations in the internal anatomy, the number and structure of chromosomes and the quality and quantity of their macromolecules. Behavioural peculiarities are also useful for the discrimination of species and genera. The time, manner and duration of copulation, site of oviposition and time and methods of emergence provide useful variations. Compatibility and incompatibility of various host seeds dependent on the amount of non protein aminoacids, antiprotease compounds, hemagglutinin fractions and other toxic substances for different bruchid species and the capability of the latter for combating the same also provide valuable demarcative information.