Cranberry Toad bugs: What are they?

Abstract: In recent years, there has been an increased concern among New Jersey cranberry growers for the potential increase in secondary pests, such as the cranberry toad bug Phylloscelis atra (Hemiptera: Dictyopharidae), because of changes in pest management strategies (e.g., adoption of new reduced-risk products and decreased applications of broad-spectrum insecticides). In 2013, we observed damage in cranberry bogs caused by the cranberry toad bug in New Jersey. Here we report results from studies being conducted to: 1) determine the life cycle of cranberry toad bugs in New Jersey cranberries; 2) determine the impact of toad bug feeding damage on cranberries, and 3) assess the efficacy of various insecticides against toad bugs. Our results from 2016 show that 1st instar nymphs start to appear by the end of June, and develop throughout July and August until early September. Adults are active from the end of July through October (harvest), and eggs are laid from end of August through October. To determine the impact of toad bugs on cranberry vine health and fruit quality, we conducted studies to characterize their feeding damage to cranberries at various densities. Treatments consisted of 0 (control), 10, 25, or 50 toad bug nymphs, replicated 5 times. Nymphs were used as they are the main target of insecticide applications and the cause of most of the early damage to the vines. Toad bug damage to uprights differed among treatments. Although there were no differences in number of damaged uprights between the control and 10 toad bugs, damage to uprights was three times higher at densities equal or greater than 25 toad bugs. No differences were found on number of damaged fruit or fruit weight. In 2016, we evaluated the efficacy of a late season application of nine insecticides (plus an untreated control) against toad bugs. A cranberry bog (var. ‘Early Black’) located at the Rutgers P.E. Marucci Center was divided into 40 (4.5 m x 6 m) plots for a total of 10 treatments replicated four times. Plots were sprayed on 5 August using a customized 2.4 m boom sprayer, and insecticide treatments were applied in 20 gal water per ha. Vacuumed samples were taken on 3 August (pre-treatment) and on 12 August (post-treatment) from 1 m2 sections in each plot with a 2‐cycle backpack aspirator. Lorsban, Sevin, Diazinon, Brigade, Agri-Mek, and Assail were effective at controlling toad bugs, whereas Beleaf, Exirel, and Closer were not effective. These studies are being repeated in 2017