Screening of different legumes for the developmental preference of Callosobruchus maculatus (Bruchidae: Coleoptera)

Pulse beetle, Callosobruchus maculatus (Bruchidae: Coleoptera), commonly known as Cowpea weevil or Cowpea seed beetle is a pest of stored grain that attacks legumes in the field and stored conditions. An investigation was conducted for screening the developmental preference of Callosobruchus maculatus in different legumes. Five different legumes were used with three replications in Completely Randomized Design (CRD). The grains of legumes were obtained from the local market of Dera Ghazi Khan. Two pairs of adult (C. maculatus) were inoculated in 20 g seeds of different legumes. Statistics on egg count, egg-laying preference percentage, hatching percentage, incubation period, larval + pupal period, total developmental period (from egg to adult), male and female population, total adult emergence, No. of holes in seeds and seeds weight loss percentage was recorded. The outcomes of this study represented that red kidney bean grains (22.54%) contained more egg-laying preference for C. maculatus as compared to other tested legumes while desi chickpea grains (14.53%) had a lesser ovipositional preference. Minimum growth period was recorded on mung bean (22.66 days), followed by cowpea (24.33 days), kabuli chickpea (27 days) and desi chickpea (30.33 days). But there was (0.0 days) no growth of C. maculatus on red kidney bean grains. In short, smooth seed coat and well-filled seeds were most preferred by C. maculatus for egg-laying, short developmental time, maximum adult emergence and increased holed seeds.