Behaviour control of Callosobruchus maculatus (F.) using flour and bran of wheat grain

Nariman, M. El-Tawelah

Abstract

Cowpea seeds is a significant crop for farmers in the world. The cowpea beetle, Callosobruchus maculatus is a major pest of economically important leguminous grains, such as cowpeas, lentils, green gram and black gram. The weight losses of pulses seeds may reach 800 g/kg in a few months. The excessive reliance on the chemical pesticides only is now under increasing restrictions because of the toxicity hazards to non-target organisms including users, the development of genetically resistant strains of insects, the high cost of application and the environmental impacts. Alternative strategies for the control of insect pests are needed to avoid the hazard associated with the chemical control of pests. As a potential solution to use chemical insecticides, the present study was conducted to evaluate bran and flour of wheat grain as natural agent which affect the behavior of C. maculatus beetle. Three bioassay methods were used, viz before insect infestation (protective method), after insect infestation (curative method) as well as repellent activity. The results indicated that the protective method of wheat flour was the best where it reduced the eggs laying and increased the reduction of progeny between 17.22 to 52.32% with the protective method compared to 0.67-19.07% with the curative one. Also, the two methods had the same trend with the wheat bran where the % reduction of F1 progeny ranged from 15.23% - 47.02% with protective method compared to 3.97-22.51% with curative one at the all tested concentrations. In addition that wheat flour had the highest repellent effect in multichoice bioassay (multirepellent) and oppositely the wheat bran had repellent activity more than that of wheat flour in binary choice bioassay (binary repellent). The present study can be recommended to utilize both bran and flour of wheat grain involving integrated pest management of leguminous seed insects since they have many advantages such as more safe, unhazardous for users and environment, cheap, easy available and easy washing.

Key words

cowpea seeds, C. maculatus, wheat flour, bran flour, repellency