Cucumber beetles are found throughout all parts of Northern America. There are two common species; the spotted cucumber beetle and the striped cucumber beetle. Both are around 1/4 to 1/2 inch long. The adult striped cucumber beetle has a yellow body and generally three black stripes down the back and it's wing covers as seen here:
The adult spotted cucumber beetle is approximately the same size as the striped, however it has a yellowish body with 10-15 black spots on its wing covers. Here is a close up of the spotted cucumber beetle (photo courtesy of Susan Ellis).
Cucumber Beetles in Gardens
Cucumber beetles will appear in gardens once the weather warms. Adults don't die but overwinter so as soon as it starts to warm, they come out and can be seen. Adult cucumber beetles will need to feed so anything growing will be fed upon immediately. If you plan on starting a vegetable garden, it's a good idea to treat early cucumber beetle activity which in turn will minimize or even eliminate those that might forage on your crops later in the year.
Though cucumber beetles prefer vine plants like cucumbers, squash and pumpkins, they'll eat what they can find early in the growing season. Feeding adults will chew holes through the leaves of new plant growth and they don't discriminate. Active adults will feed on most any garden variety plant they find and their damage can become substantial. More importantly, they are largely responsible for the spread of bacterial wilt. This fungus can be devastating to any garden so don't let cucumber beetle populations have free roam of your plants.
Once they feed, males will seek females and mate. Female cucumber beetles will then lay eggs 8-25 days after mating. Females will deposit 225-800 in small egg clusters or singly into soil cracks at the base of cucurbit plants. Eggs hatch 5-8 days later and larvae emerge. These worm like grubs will spend the next 15 days feeding on roots and stems of fruit or anything else close by that is in contact with the soil. The pupal period is 6-7 days for them to molt. The time from egg to adult for the first generation of beetles requires about a month. Over the course of the summer, there could be 2-4 generations and most will take a month or longer to completely grow.
After cucurbit plants mature and fall weather approaches, beetles will migrate to wooded landscapes, bushy areas, barns, sheds and houses to find adequate locations to hibernate. Some may overwinter a mile from their original hatching site. Next spring these hibernating adults will emerge as the weather warms and seek new plant growth to feed.
Cucumber Beetles in Homes
Since cucumber beetles overwinter (hibernate), they frequently find their way into the house. Homes which have gardens in close proximity to their siding will commonly have hibernating beetles move into wall voids and attic spaces. From there these beetles will find their way into living areas and become a pest. Though they don't bite or cause damage, they can be annoying. They'll commonly fly around lights and windows and activity will be high on any warm day. It's best to vacuum up active adults to help keep this activity minimal. Since cucumber beetle infestations can get quite severe, treatments inside the home is sometimes needed.
Cucumber Beetle Control in Homes
If you're seeing them inside the home, treat infested rooms with ECO EXEMPT KO AEROSOL. It's organic formula is both safe for people and pets yet highly effective at killing this pest.
If you suspect they are living in a wall void or attic space, treat these spaces with ECO EXEMPT DUST. This organic dust is long lasting, effective on many pests and uses essential plant oils for an active. It too won't be toxic to people or pets so it can be used inside the home without concern. Apply it to wall voids with a good HAND DUSTER. For attic or crawl space treatments, use a DUSTIN MIZER which will enable you to get good coverage.
Organic Cucumber Beetle Control in the Garden
Organic growers have long know about INSECTICIDAL SOAP to treat their gardens for cucumber beetles. It has been one of the most common organic remedy sprays for cucumber beetles used over the years. Organic insect soap will work Ok on cucumber beetles but due to their tough outer skin, soap isn't your best option. Fortunately there has been an introduction of several more actives which seem to work better. MULTI PURPOSE INSECT KILLER is one of these new products. It's like Soap but with an added synergist which helps to provide some much needed extra strength when dealing with insects like cucumber beetles. THREE in ONE CONCENTRATE in another product worth considering. It combines an insecticide, miticide and fungicide all in one spray so you're able to spray once and get protection from all the common problems organic gardeners experience. Keep in mind these organics won't last as long as the Vegetables Plus but they will kill what's present when you treat. You may even have to treat more frequently the first 1-2 weeks if the infestation is bad but once you knock down the base population, you should be able to keep them under control. Organics can be applied right up to the day of harvest and is safe for the plant so you are able to use them as needed. And all the recommended products listed above are certified compliant for organic gardening and bear the organic gardening logo.
If you prefer to use something a little stronger than the organic cucumber beetle control products listed above, apply VEGETABLES PLUS with SPREADER STICKER. Vegetables Plus is highly active on cucumber beetles and should be applied with a good PUMP SPRAYER. The Spreader Sticker will help get the treatment to cover the leaves of the plant better. This is important since cucumber beetles like to hide out of sight and can avoid treated surfaces easily. Vegetables Plus is odorless (unlike Sevin or Malathion) and can be applied weekly if needed but treatments usually last 2-4 weeks.
Cucumber Beetle Prevention
As explained above, cucumber beetles like to overwinter and hibernate where there is good plant growth for them to hide. If you allow this growth to get onto your home or garage, they will naturally end up foraging into the structure. Try not to allow plants to grow on the house or building and keep gardens away from the house. If you experience a cucumber beetle problem close to the house, you might want to spray the siding of the house to make sure they don't invade. The VEGETABLES PLUS is a good odorless product that will keep them out; INSECTICIDAL SOAP can be used too though it won't provide any residual. Cucumber beetles can be a destructive garden pest so treat problems early when first discovered. Remove dead plants and keep leaf litter minimized in help keep them away and cucumber beetle management will be easy to handle.