Ovipositional behaviour, development period, and density effect on adult survival of C. maculatus strains 
from  Indonesia, Nigeria, and Yemen, and C. chinensis strains  from  Indonesia and Kenya on cowpea and 
green gram were studied at 20°C and 70% relative humidity. 
Variations on ovipositional behaviour were found among C. maculatus as well as among C. chinensis 
strains. Variations on developmental period were found only among C. maculatus strains. The developmental 
period of Callosobruchus spp. was shorter on green gram than that on cowpea. Density effect was remarkably 
found only on  adult survival of C. maculatus Yemen strain. These  results make  useful  contribution  to  the 
species  biology,  and  have  important  implication  if  strains  of  these  species  are  accidentally  imported  to 
countries, or when new legume crops are introduced.