Red-humped caterpillar

Asked August 17, 2020, 12:02 PM EDT

For the first time I have this caterpillar eating the 2nd year cane of the black raspberries. What do you recommend? And how can I prevent them from coming again. Thank You, A Reid

Baltimore County Maryland

3 Responses

Moth caterpillar pests respond well to treatment with the organic insecticides B.t. or spinosad, though depending on their size these larvae may already be too old for the former to work. Always verify the specific product you intend to use lists brambles (or edible plants at least) on the label and follow instructions on how to apply (at what intervals, as it will need more than one application) and how long to stop spraying prior to harvest. Physically removing them and dropping them into soapy water (or feeding them to birds, which relish caterpillars) will dispose of them the fastest, especially since this larva feeds gregariously and would be easier to find. If spinosad doesn't work, other organic insecticides safe for use on edible crops may be attempted. This late in the season, however, and given how vigorous brambles are, their damage is not likely to measurably impact the plant's overall health. Birds or predatory insects may yet still discover them and reduce their numbers.


Thank you so much. Very interesting about the birds eating them. Will take your advice