Callosobruchus Maculatus Case Study

Callosobruchus maculatus, a commonly known species of bean beetles, are found in the tropical areas of Africa and Asia. The body of the species is about 3 – 4.5 mm long, reddish-brown colored with black marks on the prothorax and elytra. Typically, the females are larger and darker than the males. The larvae of the species feed on the seeds of legumes such as mung and black-eyed peas. Callosobruchus maculatus exhibits two adult forms; sedentary and dispersal (Beck & Blumer, 2014). The dispersal form is expressed by high larval density and caused by an increase in density-dependent microhabitat temperature. Dispersal forms allow the species to move in a new or high-quality habitat while in the sedentary form, the sexes are easily distinguished. Males and females bean beetles can be identified by their coloration of the plate covering at the abdomen. In males, the plate is smaller and does not contain stripes while the females have a much larger plate and dark colored stripes (Beck & Blumer, 2014). The complete life-cycle of the species takes 4-5 weeks and there are 6-7 overlapping generations can take place annually.