Western spotted cucumber beetle (Diabrotica undecimpunctata)
Western striped cucumber beetle (Acalymma trivittatum)
Pest description, crop damage and life history
Pest monitoring Specific treatment thresholds have not been established for this pest on spinach. Adults arefoliage feeders, and grubs chew on and tunnel through roots; scout accordingly. Late year infestations are insignificant. If damaging numbers are encountered during mid year, excessive foliage loss may reduce crop production. In Virginia, the following recommendations are made: to prevent cucumber beetle damage to seedlings, treat when one beetle per 10 row feet is found.
Commercial row crop covers provide good protection from cucumber beetles, provide late-frost protection, and help retain moisture. Sometimes, a crop planting can be delayed until after beetles disperse and deposit most of their eggs. Delaying planting until warmer weather also gives crops a greater chance of outgrowing beetle injury. Trap crops sometimes can be used to draw beetles away from the main crop. Trap-cropping is an unproven control method in Oregon.
Management-chemical control: HOME USE
- azadirachtin (neem oil)-Some formulations are OMRI-listed for organic use.
- kaolin-Applied as a spray to foliage, it acts as a repellent to some insect pests. Some formulations are OMRI-listed for organic use.
- pyrethrins-Some formulations are OMRI-listed for organic use.
Management-chemical control: COMMERCIAL USE
- alpha-cypermethrin (Fastac EC) at 0.014 to 0.025 lb ai/a. PHI 1 day. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.075 lb ai/a per season.
- bifenthrin/avermectin (Athena) at 0.05 to 0.12 lb ai/a. PHI 40 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.056 lb ai/a avermectin or 0.4 lb ai/a bifenthrin per year. Limit 2 treatments.
- bifenthrin (Brigade WSB) at 0.033 to 0.1 lb ai/a. PHI 40 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.4 lb ai/a per season.
- bifenthrin/imidacloprid (Brigadier) at 0.08 to 0.096 lb ai/a. PHI 40 days. REI 12 hr. Do not exceed 0.24 lb ai/a imidacloprid and 0.24 lb ai/a bifenthrin per season. Retreatment interval 7 days.
- dinotefuran (Scorpion 35SL) at 0.05 to 0.13 lb ai/a foliar and 0.23 to 0.27 lb ai/a soil. PHI 7 day foliar; 21 days soil. REI 12 hr. Do not exceed 0.266 lb ai/a foliar or 0.532 lb ai/a soil per season.
- zeta-cypermethrin (Mustang) at 0.028 to 0.05 lb ai/a. PHI 1 day. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.3 lb ai/a per season.
Note: Carbaryl, diazinon, methomyl (Lannate), or permethrin applied to control other pests usually controls cucumber beetles.