|Caterpillar feeding on developing blueberry buds. Photo: Bill Cline|
Worms or caterpillars, whatever you prefer to call them, there is an bumper crop of larvae in North Carolina this spring. My colleague, Steve Frank, ornamental and urban horticulture entomologist, spoke to the Raleigh News & Observer this week about about the large number of cankerworms present in state, and this afternoon, I received calls about caterpillar damage in two crops, blueberries and strawberries. The abundant caterpillar populations are likely due to warm spring weather; many insects have been able to begin an early generation. In blueberries, this has resulted in isolated pockets of large numbers of what appear to mixed populations of spanworms, cankerworms, and other generalist caterpillars.
|A diverse assortment of caterpillars from southeastern North Carolina blueberries. Photo: Bill Cline.|
The second question was from a research station in Virginia, where they had noticed green caterpillars present in their ripening strawberries. My suggestion for strawberries would be the same--select a narrow spectrum, bee safe material. These would include microbial (such as Bt) or insect growth regulators (such as Intrepid). See a note on pesticide recommendations. Following any treatment, plants should be carefully scouted for re infestation, since high insect pressure situations may result in more movement into crops. Just because caterpillars are present in a crop again following treatment does not necessarily mean that the treatment did not work. Insects can also move back into plantings following a treatment.