The effect of substerilizing doses of gamma radiation on the competitiveness of callosobruchus analis fabricious (Colbruchidae)

Competitiveness of Callosobruchus analis F. was studied from the adult emergence resulting when males irradiated with substerilizing doses of 1.5, 3 and 5 Kr. of gamma radiation and were confined in various ratios with unirradiated pairs of weevils. Egg production and longevity of a female decreased with the increase of irradiated males in the combination in each dose level. 1.5 Kr. population at a ratio of 9:3:3 (Irradiated male: unirradiated male: unirradiated female) produced 47.60% sterility. Increasing the irradiated males in the ratio to 15:3:3 and 24:3:3 caused 57.61 and 61.24% sterility respectively. Sterility increased with the increase of radiation dose in all combinations. Weevils irradiated with all these doses were fully competitive. (author)