Development of Callosobruchus maculatus (F.) on some pulses in Botswana

Abstract

Some aspects of the biology of Callosobruchus maculatus (F.) were studied on seven pulses viz., Cowpea (5 varieties), Bambara groundnut, Mung bean, Pigeonpea, Lablab, Soya bean and Kidney bean, under ambient laboratory conditions (temperature range: 24 - 28 °C and 61 – 77% R.H.) Oviposition by C. maculatus on the above pulses ranged from a mean of 41.10 ± 1.98 to 66.50 ± 4.85 eggs per female. The differences in the number of eggs laid per female were significant (F = 4.2, P < 0.001). With the exception of Lablab, the number of eggs hatched from oviposition by C. maculatus on the pulses was more than 90%. Emergence of C. maculatus from the pulses ranged from 18.83% on Lablab to 76.44% on Black eye cowpea. The differences in emergence numbers were found to be significant (F = 8.7, P < 0.001). The mean developmental period of C. maculatus on the pulses ranged from 30.17 ± 0.01 to 36.86 ± 0.18 days, while the longevity of the adults ranged from 1.0 – 14.0 days. Sex ratios of emerged C. maculatus were observed to be approximately 1□ : 1□ on all pulses.