Spotted Lanternflies, ever since being discovered in Maryland in 2018, have become an increasingly severe problem for the state and its trees! Most people have probably heard of them through ad campaigns, government notices, billboards, or even word of mouth, but the problem still remains. Frederick, according to the MD Department of Agriculture, is in fact a heavily infested county with comparably large populations of established, harmful lanternflies.
Most people, however, don’t know what to look for when it comes to lanternflies. They recognize them in their adult, flying form, but have no idea what their eggs or nymph stages look like. I certainly didn’t! So, this article will be a quick summary of the harm spotted lanternflies do, their stages, and what you can do to manage their populations at home.
Damage and Behavior:
Spotted Lanternflies, also known as SLFs, originally came from eastern Asia and were introduced to the East Coast through a stone shipment to the U.S.. Lanternflies, however, are merely a nuisance pest. They do not bite, sting, or hunt native bug species, and pose the biggest threat to agricultural crops and their quality. They may put stress on the plants they feed on, but only grape plants are killed by their feeding.
Lanternflies are swarm feeders, feeding in large groups on mainly trees such as the invasive tree of heaven, maples, walnuts, oaks, pines, and fruit trees. In feeding, they suck sap from beneath the bark of trees and leave a waste substance called honeydew. Honeydew can accumulate to attract other unwanted pests such as wasps, and cause growths of sooty mold that can damage the affected plant further. 
Life Cycle:
Compared to other bugs, Spotted Lanternflies have a fairly long, complicated life cycle. Lanternflies are first laid in clusters on flat surfaces in September, with clutches looking similar to scaly, discolored scabs.
Hatching begins in spring from mid-April till June. When they hatch, they’re small, spotted, black and white nymphs; also known as early instar nymphs. These nymphs will suck the sap from trees and plant stems just like their parents, becoming bigger and molting multiple times until they become larger 4th instar nymphs. 4th instar’s have distinctive red coloring, almost similar to a lady bug, but with obvious strange and abnormal features.
From here, 4th instar nymphs– which are able to be found starting in July– molt again into their adult forms. Adults will live throughout the summer until the first freeze, where they die off after females lay their eggs. Egg clutches will last overwinter and begin the cycle anew in the spring.
What to do?
As with any pest, there are many ways to get rid of them, but not all of them are advisable and potentially even cause bigger problems. The University of Maryland Extension says it best:
“In residential yards and gardens, the recommended approach is to physically kill any spotted lanternflies that are safely reachable or to leave spotted lanternflies for predators to feed on. Insecticide and other chemicals can harm non-target animals including pollinators and beneficial insects and will not effectively reach and kill all of the spotted lanternflies that are present and on the move. SLF is not harming landscape or garden plants enough to justify the risks of using insecticidal sprays. Do not spray home remedies such as white vinegar or dish soap because these items can harm other animals and plants.”
In fewer words, do not use pesticides or insecticides to kill Spotted Lanternflies. There are no Lanternfly specific poisons that will only target this pest, and such poisons could also kill amphibians and other marine life if it was to runoff into any waterway. Instead, kill any lanternflies you see with your shoe or with glove covered hands. Lanternflies also have natural predators in Maryland in the form of birds, praying mantises, and spiders. So, supporting your yard’s ecosystem with productive, native plants is a good way to not only help animals manage them naturally, but help affected plants remain strong.
But, in reality, the most important thing you can do to help stop the spread of spotted lanternflies is to report sightings here and adhere to state issued quarantines by checking your belongings for lanternfly nymphs before traveling (read more about that here and on other pages of the MD Department of Agriculture website).
Overall, remember that while spotted lanternflies are an invasive, harmful species, they are able to be controlled and managed. If you’ve ever seen a lanternfly, you’d know how dumb they actually are, so don’t let their size scare you!