The Spotted Lanternfly (Lycorma delicatula) is a highly invasive insect first discovered in the United States in Pennsylvania in 2014, originating from Asia. This planthopper possesses piercing-sucking mouthparts that draw sap from over 70 different plant species, including economically important crops like grapevines, hops, and fruit trees. The feeding process stresses the host plants, which is compounded by the sticky, sugary waste the insect excretes, known as “honeydew.” This residue encourages the growth of black sooty mold, which can inhibit photosynthesis and severely damage plant health, prompting a search for natural controls.
Native Generalist Insect Predators
Native North American insects are opportunistically learning to consume the Spotted Lanternfly (SLF), acting as generalist predators rather than specialized hunters. Controlled laboratory studies have identified several insect species that effectively prey on the SLF nymphs and adults. Among the most successful are the spined soldier bugs, a native predatory stink bug known to hunt and attack prey in groups.
Praying mantises, including the naturalized Chinese Mantis and the native Carolina Mantis, are frequently observed predators due to their ambush hunting style. Wheel bugs, a type of assassin bug, have also been noted for preying on the SLF nymphs, sometimes hatching their eggs near lanternfly egg masses.
Spiders are another common group of arthropods that ensnare and consume the SLF, especially the smaller nymphs. While these native predators contribute to localized population reduction, they are not specialized enough to provide widespread control. Their hunting is often limited by the sheer numbers of the pest and their populations are easily impacted by traditional pest management efforts.
Specialized Biocontrol Agents
The most promising long-term strategy involves classical biological control, which introduces specialized natural enemies from the SLF’s native range in Asia. This effort centers on tiny parasitic wasps, known as parasitoids, that have co-evolved with the pest. The goal is to regulate the lanternfly population naturally, similar to how it is managed in its home environment.
Two primary insect agents are currently undergoing rigorous testing in the United States, focusing on their host specificity to ensure they pose no threat to native insect species. One is Anastatus orientalis, an egg parasitoid that targets the mud-like egg masses laid by the lanternfly. This wasp lays its own eggs inside the SLF eggs, destroying the developing pest.
The other agent is the nymphal parasitoid, Dryinus sinicus, which attacks the younger, wingless stages of the lanternfly. The female wasp stings a nymph and deposits an egg on or inside it; the resulting larval wasp then consumes the nymph internally. These specialized parasitoids are expected to provide a consistent, self-sustaining method to manage the invasive pest population over time once approved for widespread release.
Other Ecological Predators
Beyond insects, a variety of other animals have been documented feeding on the Spotted Lanternfly, contributing to localized control efforts. Backyard chickens frequently consume both the adult and nymph stages of the pest, making them effective, if small-scale, predators. Several species of wild birds have also adapted their diets to include the invasive insect.
Birds noted for consuming the SLF include:
- Northern Cardinals
- Gray Catbirds
- Blue Jays
- Tufted Titmice
Small mammals, including squirrels and bats, have also been observed preying on the lanternflies. Additionally, entomopathogenic fungi, which infect and kill insects, are being studied as a potential non-insect biological control agent.
Lanternfly Defenses and Predation Barriers
The Spotted Lanternfly has several inherent biological and behavioral traits that make it a difficult target for predators, explaining why native species have not yet controlled the outbreak. One significant defense is the sequestration of toxins from its preferred host plant, the invasive tree-of-heaven (Ailanthus altissima). By feeding on the tree’s sap, the lanternfly accumulates bitter-tasting chemical compounds, making it unpalatable or mildly toxic to many potential predators.
The insects also employ multiple behavioral defenses to evade capture, including a rapid jumping ability that allows them to quickly escape. When physically contacted, adults may perform a deimatic display, flashing their conspicuous red hindwings to startle a predator. If seized, they may also engage in “death feigning,” collapsing with their legs folded to appear inedible or deceased.
The nymphs, particularly the younger instars, have a waxy coating on their bodies that may serve as a physical barrier to some predators or contact insecticides. Additionally, adults often feed high up on tree canopies, placing them out of reach for many ground-based or smaller predators. This combination of chemical, physical, and behavioral defenses presents a significant barrier to effective natural predation.