Analysis of mycobiota and oviposition of Callosobruchus maculatus in beans variety Vigna angularis and Vigna unguiculata

Abstract: Beans are an important source of protein in the diet of several societies. In inadequate storage conditions may occur insect infestations and fungal contamination. This study analysed different samples of Vigna angularis and Vigna unguiculata, purchased in retail. There were determined oviposition and viability of Callosobruchus maculatus eggs in adzuki bean (V. angularis, n = 10), cowpea (V. unguiculata, n = 16) and black-eyed (V. unguiculata, n = 13). Twenty adult insects with 1-5 days of emergency were confined in 50 grains and assessed the number of eggs in 8 days and emerged insects to 40 days, with 5 replicates per variety. C. maculatus oviposited on average 19.4 eggs in adzuki beans, but without viability. In black-eyed and cowpea egg viability was 31.40 and 13.71%, respectively. Regarding mycobiota, the direct plating method of grains on Sabouraud agar showed the predominance of Eurotium chevalieri fungus isolated in 100% of the samples adzuki. The cowpea presented the frequency of 81.2% of yeast and 12.5% of Aspergillus niger. The black-eyed presented the frequency of 100% of yeast and 61.5% of Aspergillus flavus. It was concluded that the storage conditions should be monitored in the retail market in the prevention of insect attack and fungal both varieties.