My zucchini plants die just as they start to blossom. Later in the season they are covered with a gray beetle. What can be done without using pesticides?
Hardiness Zone: 6a
By James from Wayland, MI
Destroy crop residues after harvest and reduce overwintering sites by tilling.
Control of Curcurbit Insects
Cucumber beetles or squash beetles can be controlled effectively using carbaryl (Sevin), but wait one day after spraying before harvest. For aphids or spider mites use an insecticidal soap such as Concern Insect Killing Soap or Safer Brand Soap. Control heavy populations of aphids or spider mites with neem oil extract (such as Green Light Neem Concentrate or Bonide Bon-Neem).
For vine borers and pickleworms control after mid-June, apply carbaryl (Sevin) or neem oil extract weekly, and spray or dust in the evening to not kill pollinating insects. Wait one day after spraying carbaryl before harvest. Rotenone (such as Hi-Yield Rotenone Dust) is effective against younger squash bugs, but not against the adults. Esfenvalerate (such as Ortho Bug-B-Gon MAX Garden & Landscape Insect Killer RTU) or permethrin (such as Bonide Eight Insect Control Vegetable, Fruit & Flower Concentrate) or bifenthrin (such as Ortho Bug-B-Gon MAX Lawn & Garden Insect Killer Concentrate) will control cucumber beetles, squash bugs, squash vine borers and pickleworms, call your county agent for more info,good luck.