From our perspective as passion flower vines, we are vibrant and complex organisms, often celebrated for our stunning blooms and delicious fruit. However, our lush foliage and vigorous growth can unfortunately attract a variety of pests that see us not as a wonder of nature, but as a meal. Understanding these invaders from our point of view is key to maintaining our health and beauty.
We often first notice aphids as a slight puckering or yellowing on our newest, most tender leaves and stems. A sticky residue, known as honeydew, soon covers our foliage, which can lead to the growth of sooty mold, blocking our sunlight absorption. This honeydew also attracts ants, who will fiercely protect the aphids from their natural predators. A strong spray of water can dislodge these soft-bodied pests. For more persistent infestations, insecticidal soaps or neem oil applications are effective and gentle on our delicate systems, helping to restore our vital sap flow.
Spider mites are a particularly pernicious problem, especially during hot, dry conditions which stress us out. You might notice a subtle stippling of tiny yellow dots on our leaves—each one a spot where a mite has pierced and drained our cells. As their numbers grow, fine, silken webbing appears on our undersides, and our leaves may turn bronze, then brown, and eventually drop off, severely weakening us. Increasing humidity around us and routinely spraying our leaves with water can discourage them. Miticides or horticultural oils are necessary to penetrate their protective webbing and stop their damaging feast.
Scale insects are masters of disguise. They attach themselves to our stems and the veins on our leaves, appearing as small, bumpy growths rather than insects. They remain motionless, inserting their piercing mouthparts to siphon our nutrients. This causes yellowing, leaf drop, and a general decline in our vigor. Their hard, waxy coating makes them resistant to many treatments. They can be physically scraped off or smothered with a dormant oil application during our winter dormancy. During the growing season, carefully timed applications of horticultural oil can suffocate the immature crawler stage before they form their protective armor.
While we have a famous relationship with Gulf Fritillary and Zebra Longwing butterflies, whose caterpillars rely on us for food, an overabundance can be devastating. We don't mind supporting a few future pollinators, but large groups can skeletonize our leaves, stripping us of our ability to photosynthesize. The tell-tale signs are irregular holes in our leaves and dark droppings (frass) on the foliage below. For non-butterfly species, they can be hand-picked. Bacillus thuringiensis (Bt) is a natural, soil-borne bacterium that is an effective treatment, specifically targeting caterpillars without harming other beneficial insects that we rely on for our ecosystem.
