Striped cucumber beetle adults have arrived in our garden plots. If you are growing squash, cucumber, zucchini or other cucurbit you should be looking for eggs under the leaves closest to the soil.
The eggs are oval and yellow to amber-colored. If you find eggs, remove and destroy them.
The beetles – which are yellow with black stripes – are currently feeding on leaves. Soon, if not already, female beetles will lay eggs. Once the eggs hatch the larvae will feed on the roots and pupate in the soil. Come August, the cycle will be complete and what are now eggs will be adults.
What Damage Do They Do?
They eat leaves and roots. Mature cucurbits can handle some damage. If beetle numbers are high the damage can mean reduced yields. A secondary problem with cucumber beetles is that they are vectors to a disease known as bacterial wilt. If you notice leaves turning a dark green, wilting and then dying, this is a symptom of bacterial wilt. Some plants – such as pumpkins – are more susceptible than others to this disease.
How Do I Know if My Plants have Bacterial Wilt?
Cut a section on the stem. Hold the stem together and then slowly pull it apart. If bacterial wilt is present the sap will appear string-like between the cut ends.
How to Control and When
Striped cucumber beetles are most active evenings and through the night. Since it is most effective to spray the beetle directly this would be the ideal time to apply a spray of Neem Oil. If you find beetles on your squash apply neem oil in the next two weeks. In addition to aiming at the beetle, be certain to spray under the leaves at the base of the plant where eggs and larvae are likely to be located.
A labelled spray bottle of Neem Oil will be placed in the shed in the next few days for everyone to use.
Never, Never, Never spray in the heat of the day. This can kill a plant. Wait until evening and aim for contact with the beetle.
If you have questions, leave a comment below.