Potential Reproductive Activity of Callosobruchus subinnotatus Pic. (Coleoptera: Bruchinae), Bambara Groundnut (Vigna subterranea Verd.) Depredator

Abstract

Callosobruchus subinnotatus Pic. (Coleoptera: Bruchinae) is the most important depredator of Bambara groundnut seeds (Vigna subterranea Verd.) in West Africa. In view of an efficient control of its populations, some of the biological parameters of C. subinnotatus were determined under laboratory conditions (30 ± 2 °C; 72 ± 2% HR; 12h: 12h LD). The results have shown that the mean lifespan of females (11.36 ± 1.85 days) is shorter than that of males (15.14 ± 2.4 days). The female lays 80.83% eggs within the first 6 days after her emergence with a mean fecundity of 121.34 ± 27.62 eggs. The means egg fertility, survival and adult emergence rates are respectively 96.19 ± 1.45%, 97.72 ± 1.08% and 94.01 ± 2.14%. The sex ratio is in favor of males with a mean of 0.845 ± 0.08. The monitoring of adult emergence in connection with their reproductive status showed that the offspring of C. subinnotatus consists of two physiotypes, a reproductive type that appears during the first 8 days of emergence with a short development time (28.35 ± 3.36 days) and a non reproductive type that appears from the 9th day of emergence with a longer development time (37.92 ± 3.92 days).

Cassia tora (L.) Seeds, An Alternative Host to Callosobruchus subinnotatus (Pic.) Infestation: A Preliminary Research Note

“…Callosobruchus subinnotatus is an insect that was widely known to attack grain legumes [Nyamador et al 2016]. Maina and Lale [2004] stated that C. subinnotatus is one of the field-to-store bruchid pests that attack grain legumes in tropical Africa and Asia.…”