Brief Summary: Unmated Adults In Life History

LIFE HISTORY: Unmated adults overwinter in plant debris, crevices of fences and buildings, and other protected sites around woodlands, gardens and agricultural fields. They become active at temperatures above 50 °F and begin to mate in the spring. Eggs hatch in 7-10 days and larvae take about 15 days to complete development to the pupae stage. Pupae live about 7 days before becoming adults. In east central Utah, two summer generations of adults occur.
DAMAGE: Both adults and larvae of the striped cucumber beetle feed on cucurbits with chewing mouthparts. Larvae of the spotted cucumber beetle do not feed on cucurbits but the adults will feed on cucurbit leaves and sometimes soft fruits. This makes the spotted cucumber beetle a less severe
Use monitoring to detect adult beetles and estimate their population numbers. Start monitoring when seedlings emerge or after transplanting, and through the fruiting stage.
• Monitor with field scouting. Scout by checking all of the above-ground parts of plant hosts. Newly emerged or transplanted cucurbits should be checked two or three times per week. Scout the field margins in the early season and if adult beetles are detected, scout random locations in the center of fields.

• Monitor with traps. Use cucumber beetle traps with attractive odors (pheromone traps baited with Eugenol or similar compounds, kairomone traps with cucurbit fruit, floral or root extracts) and colors (yellow sticky traps). Make sure you have traps specifically for either spotted cucumber beetle or striped cucumber beetle depending on the species of interest. Lures will be different for each species. Follow the timing and format for field scouting, with early emphasis on field margins.

• Lure beetles away from cash crop with trap crops and baits. Trap crops and baited traps can help lure cucumber beetles away from main crops and help to monitor their
When using insecticidal sprays, ensure that they penetrate the crop canopy and contact damaging life stages of beetles. This can be done by depositing spray droplets on the top and underside of leaves, stems, flowers, and fruits and also by drenching the soil surface when larvae are active. Timing of insecticide treatments is critical in cucumber beetle control. Treatments should target susceptible life stages as follows:
• Spring: overwintered adults. Treat before feeding injury is significant and before mating and egg-laying.
• Late spring and early summer: larvae. Treat when eggs hatch and before larvae move to plant roots to feed.
• Mid and late summer: adults and larvae. Treat high number of adults and larvae to prevent feeding damage to leaves, stems, flowers, and fruits.
• Isolated fields during spring or summer: overwintered adults. Despite good early-season control in production areas, adults may move to main crops from nearby infested fields during mid and late summer.
Natural enemies of cucumber beetles include ground beetles, soldier beetles, braconid wasps, tachinid flies, and entomopathogenic nematodes. Nematodes can suppress larvae and pupae in the soil while the others listed attack adults, eggs, and larvae on the soil surface or on plants. Commercial purchase and release of natural enemies has not shown to be effective on cucumber