Parsley Worm

Papilio polyxenes

The Parsley Worm is the larvae of the black swallowtail butterfly and is one of the prettiest caterpillars you will find. It is green with yellow and black bands and can projects orange horns (along with a distinctive smell) when threatened. It can be found over most of North America and feeds on the leaves of most members of the carrot family (Apiaceae) including parsley, carrot, dill, celery, fennel and parsnip.

Parsley Worms are quite voracious and can strip a plant of leaves very quickly, however some gardeners don’t even try to control them as they turn into such a beautiful butterfly. If you want to control them and they aren’t too numerous the best control is to hand pick, though they are often well camouflaged and hard to spot (the damaged leaves and droppings help to give away their location). You might try moving them to a suitable wild member of the Apiaceae. If there are too many to hand pick you might try a spray of B.T. They are preyed upon by birds, ground beetles, spiders, small wasps and a host of other predators and this is the best way to control them. If they are really bad you could use row covers to prevent the moths laying eggs on them.

Photo: Jerry A. Payne, USDA Agricultural Research Service, Bugwood.org