Worms on Passion Plants

Pest Varieties

• Most worm pests do not attack adult passion vines. However, passion vine seedlings and young plants may be attacked by cutworms. These pests cut the main stem of freshly-germinated or still-young passion vines and eat the top portions. The roots are seldom healthy and developed enough at this time to produce new vines and foliage, so the plant will die entirely.

Symbiotic Partners

• Passion vine has compounds that are toxic to many caterpillar worms. However, there is only one type of butterfly whose larval stage can withstand these toxic compounds: the heliconids. These butterflies repay the passion flower vine for the service of its nutritious leaves by pollinating the flowers once they reach the adult butterfly stage. While the loss of foliage to feeding heliconid caterpillars slows the plant's growth, they do not destroy the host plant.

Considerations

• Cutworms are the larval stage of several types of nocturnal moths. They lay eggs near the passion vine; then the larvae cut the vine. Individual plants can be protected by placing an aluminum sleeve around new transplants or seedlings so that the bottom of the sleeve extends 2 inches into the ground and the top of the sleeve extends several inches above the soil. If cutworms are a frequent problem in the garden, the sleeve should remain for more than one season to allow the plant to mature before removing it.

Caution

• There are ecological worm killers called BT, or Bacillus thuringensis. These are not

  effective on cutworms but will kill heliconid caterpillars. When using an aluminum sleeve, ensure that it is a sheet wound up to make a sleeve and not a solid cylindrical sleeve that will be impossible to remove from a mature passion vine.