Species complex, feeding behavior, and control of flea beetles in southern highbush blueberries in Florida

Flea beetles are the most damaging summer pest of southern highbush (SHB) and rabbiteye (RE) blueberries in the southeastern US. Beetles feed on the leaves and reduce the next season’s crop yield. The damage by flea beetles result from a complex of species that occur in the field after berry harvest. The objectives of our study were to identify the most common species of flea beetles that feed on SHB and RE blueberries in Florida. In addition, we wanted to assess their feeding behavior, and blueberry varietal susceptibility to beetles. Finally, we wanted to explore insecticidal tactics for management of flea beetle populations. Field surveys were conducted on two 5-acre blocks of SHB where in situ counts and laboratory identifications were done to establish beetle species complex within the field. In a choice and no choice tests, beetles were exposed young leaves (summer growth) or old leaves (spring growth). Colaspis pseudofavosa Riley was the most abundant species accounting for 65% followed by Systena frontalis Fabricius with 30%. Both beetles preferred to feed on young leaves. However, C. pseudofavosa made shot-holes while S. fronatalis caused bronzing effects on the leaves. Additionally, in the summer of 2008 and 2009, we conducted laboratory and field and studies to evaluate varietal susceptibility of both RE and SHB to flea beetles. There were no significant differences between the blueberry species or among the varieties. Finally, among the six insecticides evaluated for management of flea beetles, Mustang^® was the most effective in suppressing their populations.