BeneficialSquash vine borerNot recommended
Bt for squash vine borer
Bacillus thuringiensis kurstaki · microbial insecticide
Against squash vine borer
Injecting Bt into squash stems is widely recommended online. One South Carolina study found Bt comparable to the insecticide standard, but a 2018 review found sprays beat injections and University of Minnesota says Bt is not effective because larvae inside stems are protected.
RateNo label rate for squash vine borer — Bt was not on the EPA-labelled list for this pest (eOrganic 2012)
TimingOnly a spray at the stem base while eggs hatch could reach larvae; once inside the stem they are out of reach
macro · bt (kurstaki) on squash vine borer
The pestSquash vine borerMelittia cucurbitaeVines wilt suddenly; wet, sawdust-like frass at the stem baseFull pest profile →Before you order
A bacterium sprayed on leaves. Caterpillars that eat it stop feeding and die within a few days. It works only on the larvae of moths and butterflies, and has little or no effect on bees, lady beetles, lacewings or parasitic wasps. How it works, how to tell it has established and the supplier list are on the full Bacillus thuringiensis kurstaki profile.
Other controls for squash vine borer
- Steinernema carpocapsaeNematode · Per package directions — no extension source gives a per-stem dose