Caterpillar Control on a Passion Flower Vine

During the fall, many species of butterflies make their way through the South searching for food on their migratory path. Certain species, of course, are attracted to certain plant species. The Gulf Frittilary butterfly depends on many species of passionflower for their survival. While gardeners may wish to discourage heavy infestations, light infestations of the Gulf Frittilary caterpillar should be encouraged.

The Gulf Fritillary caterpillar is orange with black spines along the length of its body. The adult female caterpillar lays its eggs singly on the leaves of the passionflower vine. The eggs are small and yellow. The Gulf Frittilary prefers to lay its eggs on several different species of passionflower, including maypops (Passiflora incarnata), running pop (Passiflora foetida), blue passionflower (Passiflora caerulea) and corky-stemmed passionflower (Passiflora suberosa).

In large numbers, the butterfly larvae are capable of defoliating a passionflower vine. While such devastation is by no means desirable, encouraging the larvae is recommended, as the butterflies rely on passionflower vines for their survival. According to Cathy Nordstrom of eNature.com, a healthy passionflower vine should bounce back from defoliation. Just remember that the two species have been evolving together for millions of years -- the plant will know what to do.

If you find that you can't stand to watch your passionflower vines be destroyed every year, you might consider either controlling the caterpillar population, increasing the passionflower population, or both. Growing more passionflower vines will disperse the amount of caterpillars among many plants, thus preserving the vines. If that isn't an option, inspect the vines for caterpillar eggs and remove some of them before they can hatch. Do not remove all the eggs.

The polka dot wasp moth's larvae look similar to that of the Gulf Fritillary. These caterpillars are very destructive and the adults are no more desirable than the larvae. You can identify their eggs because there are multiple eggs per leaf, as opposed to the single egg of the Gulf Fritillary. The larvae are about an inch long and feed on the underside of oleander bushes. They shouldn't appear on your passionflower vine so don't remove Gulf Frittilary eggs out of fear that they are polka dot wasp moth eggs.