Screening of 25 cowpea genotypes for resistance to Megalurothrips sjostedti Trybom in southern Ghana

Abstract

In sub-Saharan Africa, Megalurothrips sjostedti Trybom are the most destructive insect pest of cowpea. It causes approximately 100% reduction in cowpea yield. Synthetic insecticides are widely used in controlling this pest, however, health and environmental hazards are another challenge. This study sought to evaluate 25 cowpea genotypes from Ghana, Mali, Nigeria, Niger, Burkina Faso, Togo and South-Sudan for resistance to this pest under field screening using a 5 by 5 alpha lattice design with 2 checks at University of Ghana farms. The results revealed Laduni 1B as resistant, 20 moderately resistant and 4 susceptible genotypes were also identified in this study. In the determination of correlated and non-correlated variables, ten traits were reported important to the resistance of cowpea genotypes to flower bud thrips. The genotypes with resistance could be used to introgress the resistant trait into other preferred but susceptible cowpea varieties.

A Maximum Dose Bioassay to Assess Efficacy of Spinetoram against Cowpea Thrip Megalurothrips usitatus in China

“…Although the hot and humid environment in Hainan provides favorable conditions for yardlong beans, it also contribute to the proliferation of diverse pests infesting yardlong beans [8]. Among the handful of pest species, thrips are particularly the dominant pest, resulting in a 20-30% reduction in cowpea yield, and in severe cases, the reduction can reach up to 80% or even complete crop failure [9][10][11][12]. Four thrip species, Megalurothrips usitatus (Bagnall), Frankliniella intonsa (Trybom), Thrips palmi (Karny), and Thrips hawaiiensis (Morgan), were found on cowpeas [13], among which M. usitatus is the dominant species in most cowpea-producing areas in China [14].…”