kurstaki (Btk) is a group of bacteria used as biological control agents against lepidopterans (moths and butterflies).
During sporulation, Btk produces a crystal protein that is lethal to lepidopteran larvae.
[3] Btk is available commercially and is commonly known as "Garden Dust" or "Caterpillar Killer", both of which are produced by Safer Brand.
Other subjects with hay fever reported more significant effects, including throat irritation, upset stomach, and difficulty sleeping.
It further showed that low doses of Btk, regardless of the strain, led to significantly greater longevity in the wasps.