Effects of various snap bean cultivars on insect pests and beneficials

Snap bean is an important crop in the United States. Insecticides are commonly used in snap beans, but many pests have developed resistance to the chemicals, and beneficial insects are threatened. However, host plant resistance is a sustainable alternative. The population dynamics of insect pests, pollinators, and natural enemies were assessed on 24 snap bean cultivars weekly from 25 to 60 days after plant emergence. The least number of sweetpotato whitefly (Bemisia tabaci; Middle East-Asia Minor 1) eggs was observed on the cultivar ‘Jade’, and the least nymphs were found on cultivars ‘Gold Mine’, ‘Golden Rod’, ‘Long Tendergreen’, and ‘Royal Burgundy’. The numbers of potato leafhopper (Empoasca fabae) and tarnished plant bug (Lygus lineolaris) adults were the lowest on cultivars ‘Greencrop’ and ‘PV-857’. The highest numbers of adults were found on Week 1 for B. tabaci and Mexican bean beetle (Epilachna varivestis); Week 3 for cucumber beetle species, kudzu bug, and E. fabae; Weeks 3 and 4 for thrips; Week 4 for L. lineolaris; and Weeks 5 and 6 for bees. Temperature and relative humidity were correlated with B. tabaci, bee, E. varivestis, and predator ladybird beetle populations. These results provided valuable information on pest management on snap beans.