Recently the cranberry toad bug, Phylloscelis atra (Figure 1), has become a problematic pest of cranberries in New Jersey. Toad bugs are hemipteran insects, similar to blunt-nosed leafhoppers, but belong to the Family Dictyopharidae (planthoppers) as opposed to leafhoppers, which belong to the family Cicadellidae.
Toad bugs feed only on cranberries. This insect has a single generation per year (Figure 2). It overwinters as eggs. The nymphs appear by the end of June through August, and the adults from August through October. Eggs are laid from September through October.
Feeding damage can be noticed in two stages. First stage feeding damage on vines causes closing in (towards the branch) of the leaves on the new growth. Second stage feeding causes changed in color (reddish to brown) of new growth. The damage can be seen from July until harvest. This damage will cause dying of the branch and the berries to shrivel up (Figure 3). Heavy infestation will result in dwarfed berries.
To determine infestation, lightly sweep problematic beds (bugs should be easy to catch in sweep nets as they are very active).
Because this is a new pest there is no threshold established yet. Research is currently underway to determine the impact of toad bug density on cranberry yield. Thus, insecticide applications should be based on the relative number of bugs per sweep compared with other sites and previous history of infestation.
Currently, the best option for growers is to use Sevin (for Ocean Spray growers, Sevin should be applied before August 1st). Other options include: Diazinon (chemigation only- no aerial sprays) and Lorsban (not a post-bloom option for Ocean Spray growers). If infestation is high, treatments should be applied within the next 2 weeks.
For more information, please see “The Cranberry Toad-Bug” by F.A. Sirrine and B.B. Fulton. 1914. New York Agricultural Experiment Station. Bulletin No. 377. Department of Agriculture, Geneva, NY.