Mungbeans (Vigna radiata (L.) Wilczek) is a legume that belongs to the family, Fabaceae. The crop is commonly utilized in Asian continent and it has spread across the globe just like other important crops. This legume is prone to infestation by the genus Callosobruchus. This study investigated the inter- and intra-species similarity or variation in emergence potential of Callosobruchus species from mungbean. Three species of Callosobruchus (C. maculatus, C. chinensis and C. rhodesianus) and four strains of C. maculatus (Cameroon, Brazil, Yemen and Uganda strains) were used for the study. The test insects were allowed to oviposit separately on mungbeans and for each species/ strain, ten (10) seeds having hatched eggs were monitored individually. Total adult emergence per seed, day of commencement of emergence and cessation were monitored. Emergence Time of 50% of the total emerged population (ET50) and the time for 50% seed loss (SLT50) were also estimated. Generally, emergence cessation was on the 30th day; however, this was delayed in Yemen and Brazil strains of C. maculatus. The shortest SLT50 (3 Days) was observed in C. chinensis and the longest (7 days) in C. maculatus (Brazil and Yemen strains). C. maculatus (Uganda) had the shortest ET50 (2.81 days) and C. maculatus (Yemen) had the longest (6.35 days). C. chinensis had the highest adult emergence (26 adults) and C. maculatus (Uganda) had the lowest (9 adults). Based on SLT50 and ET50, African populations of Callosobruchus species show potentials for early emergence from mungbeans. Therefore, the preservation of mungbean seeds from Callosobruchus species should be handled properly on the African continent.
Key words: Mungbean; Callosobruchus; species; strain; adult emergence; seed loss