Have you heard about the invasive spotted lanternfly (SLF)? The SLF (Lycorma delicatula) is not a fly, but rather a planthopper that has an adult stage that looks a lot like a moth.
It’s a serious pest on many plants. It commonly feeds and lays eggs on the invasive tree-of-heaven (Ailanthus altissima). It also feeds on fruit crops including grapes, apples, and plums, as well as forest trees such as oak, maple, and walnut. This insect will be on different hosts at different times in its life cycle.
This is a sap-feeding insect (think mosquito for plants), and this feeding can weaken host plants. The sugary sap runs right through the pest and drips out onto everything below. The drippings are called honeydew. The sticky, sweet honeydew attracts bees, wasps, and other pests. A black sooty mold fungus grows on honeydew. It can be so thick that any leaves coated with the fungus will not photosynthesize, weakening the plant even more. The spotted lanternfly produces extremely large amounts of honeydew, making it unpleasant to be under an infested tree.
The spotted lanternfly overwinters in clusters of eggs on host plants as well as on any hard surface. If the eggs are on mobile surfaces (such as cars, camping trailers, railroad cars, or wood pallets), they are easily spread. The egg masses are a nondescript gray and can be easily overlooked.
The eggs hatch in spring and early summer. The nymphs feed on a range of host plants and go through four stages, with the first three being black with white spots and the last stage red with white spots and black stripes. They are about the size of ladybugs.
The 1-inch-long adults begin to show up in about late July and through the fall until a freeze kills them. When at rest, the insect’s wings close over its body. The first area of the closed wings is a pretty pinkish-gray with black spots. The outer one-third of the wings look like it’s covered in tiny tiles. When the back wings are exposed, they are a vivid red with black spots, and then black and white. This view of the SLF is very pretty.
The SLF is a serious economic threat to orchards, vineyards, woodlands, and landscapes. The adults can gather together by the thousands, creating a nuisance as they drop huge amounts of honeydew. A single infestation can kill grapevines and small trees.
The SLF is found in Connecticut, Delaware, Indiana, Maryland, Massachusetts, New Jersey, New York, Ohio, Pennsylvania, Virginia, and West Virginia. Scattered reports of SLF have been recorded in Iowa, North Carolina, and other states. The states in which it’s common often have quarantines in effect to prevent the spread of the egg cases. Any SLF found in any other state should be reported to your local Extension office or your state Department of Agriculture.
