Comparison of the effectiveness of the common bean fly (Ophiomya spp.) control methods: Implications for resistance breeding: A meta-analysis

The bean fly ( Ophiomya spp.) is one of the most destructive field pests of the common bean ( Phaseolus vulgaris L.), notably in Eastern and Southern Africa. Several studies have recommended a range of methods for bean fly control. Nevertheless, the effectiveness of management practices and their impact on grain yield is not fully understood to help prioritize and guide integrated management of the pest spearheaded by host plant resistance. A meta-analysis was conducted involving 18 studies on bean fly control methods. The highest achieved grain yield was 3761.00 kg/ha from the chemical control, and the lowest was 14.10 kg/ha from the genetic control, indicating a low level of bean fly-resistant lines in the current breeding stocks. The control methods had effect sizes ranging from small (0.19) to large (1.38). The chemical and integrated control methods had the highest ES values of 1.21 and 1.38, respectively, but had wide 95% confidence intervals. The metadata suggests variable efficacy of the control methods, and breeding for host resistance is yet to be up-scaled to control the bean fly and bolster grain yield effectively. No studies have reported the effectiveness of biological control against bean fly based on the grain yield of candidate common bean genotypes. Overall, the genetic control method with an ES (0.19) contributed to a relatively small effect, with CIs of -0.8 and 0.56 overlapping the null effect. This suggests that the level of bean fly resistance in the available genetic pool is still low, resulting in low yield potential, which requires concerted breeding.