ABSTRACT
The influence of larval diet and population density on pre-adult developmental rate, adult population sizes, pre-pupal survival and sex ratio was investigated. Mean developmental period varied significantly with low larval densities. Similarly there were significant variations of developmental periods with different diets. A comparison of the survival rate of larvae fed with the three types of diets showed significant variations (P<0.05). Sex ratio varied significantly from the 1:1 ratio in adult raised from larva density of 30L/300ml, 60L/300ml, 150L/300ml and 300L/300ml larva density. Mean pre-adult developmental period of larvae fed with kidney, kidney/liver and liver powder were 13.50±1.62, 8.88±0.52 and 10.25±1.170 days respectively and those for densities of 30L/300ml, 60L/300ml, 150L/300ml, 300L/300ml were 8.83±0.73, 8.83±1.33, 13.17±2.13 and 12.67±1.96 days respectively. The mean pre-pupal survival for larva fed with kidney, kidney/liver and liver powder respectively were 15.75±18.34, 52.00±18.59, and 46.50±15.21 days respectively and those for densities of 30L/300ml, 60L/300ml, 150L/300ml, 300L/300ml were 16.00±3.21, 42.00±7.94, 96.67±6.84 and 48.33±5.17 respectively. The mean pre-adult survival for larvae fed with kidney, kidney/liver and liver powder were 10.00±1.68, 9.50±1.37 and 8.75±0.48 respectively and those for densities of 30L/300ml, 60L/300ml, 150L/300ml, 300L/300ml were 8.50±0.50, 7.67±0.17, 8.83±0.17, and 12.67±1.64 respectively. Analysis of the results shows that intra-specific competition was high for diet and effect of density was greater at extreme densities.
