Both Japanese beetle (Figure 1) and green June beetle (Figure 2) are active on a number of fruit and vegetable crops across the Commonwealth. Both of these are scarab beetles; however, Japanese beetle is primarily a foliage feeder, while green June beetle is primarily a fruit feeder. Japanese beetle can feed on foliage weeks from harvest, but green June beetle often arrives just as the fruit begins to soften close to harvest.
When these pests become common, control may be warranted.
We have a number of materials to control Japanese beetles and green June beetle that are listed in UK’s Commercial Small Fruit and Grape Spray Guide (ID-94), but some of these materials may have pre-harvest intervals (PHI) that limit their use during the harvest period. Producers controlling these pests during harvest must follow PHI carefully to ensure pesticide residues are minimal and to safeguard food safety. With some fruit crops the options for control of these beetles may be limited during the harvest period. We have had some success using neem oil or azadirachtin products on a 2-day interval to repel these beetles from orchards during the harvest period. These products have a 0-day PHI.
With smaller berry crops like blackberries, raspberries, and blueberries in backyard plantings, fine mesh cloth can be used preventively to keep these scarabs off plants. Many producers have noticed that the first Japanese or green June beetles that colonize the plants with attract additional recruits quickly. So it is helpful to keep the initial colonizers off plants during the first few weeks of adult activity.
By Ric Bessin, Extension Entomologist