Plant Doctor Archive

Loopy caterpillars

WHAT do "loopy" caterpillars start from? They are bright green with legs front and back and loop in the centre when moving. They play havoc with my geranium leaves, leaving them full of holes.

"LOOPY" caterpillars, or "loopers" as they are also known, are the larvae of a group of moths and feed on a wide range of plants. They hatch from eggs laid by the adult female moth, which in some cases can lay up to 1000 eggs in her short life. Loopers can range in colour from green to brown depending on species and are generally around 30-40mm long at maturity.

You can squash them with your fingers when still small or spray them. There's a wide range of products you could use, such as derris dust, garlic and pyrethrum and Mavrik, although if damage isn't severe or particularly disfiguring you could simply do nothing as most plants can tolerate losing a few leaves to loopers.

Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.