The Spotted Lanternfly (Lycorma delicatula) is an invasive planthopper that poses a significant economic and ecological threat across the United States. Originating in Asia, it was first identified in Pennsylvania in 2014 and has spread rapidly, primarily by hitchhiking on vehicles and goods. The species feeds by piercing plant tissues to extract sap, weakening trees and vines, reducing crop yields, and making them vulnerable to disease. This behavior damages crops like grapes, apples, and hops, as well as hardwoods such as maples and walnuts.
The insects also excrete honeydew, a sugary substance that promotes black sooty mold growth, impeding plant photosynthesis and creating a nuisance. Implementing non-chemical controls like trapping is a practical way to manage populations and protect agriculture and forest health.
Constructing a Safe DIY Circle Trap
The safest and most effective method for intercepting these climbing insects is a non-sticky circle trap, which uses a funnel-based collection system. This design is preferred because it significantly reduces the risk of capturing non-target wildlife, such as beneficial insects, small birds, or bats—a major drawback of sticky bands. The trap works by redirecting lanternflies, which naturally climb upward on tree trunks, into a container from which they cannot escape.
To construct this trap, gather plastic-coated window screening, two plastic milk jug tops, duct tape, hot glue, sturdy bendable wire, and a collection container (like a gallon-sized zip-type bag). Cut the spouts off the milk jugs and secure them together at the rim with tape and hot glue to create a double-sided funnel. Next, cut a rectangular piece of screening, approximately 30 by 23 inches, and shape it into a cone or skirt.
Secure the narrow end of the screen skirt around one end of the funnel assembly using hot glue, ensuring the edges overlap to prevent gaps. The wider end of the screen wraps around the tree trunk, forming a skirt that directs climbing insects inward toward the funnel. Incorporate the sturdy wire along the rim of the screen to give the skirt structure and help it flare out, forcing the lanternflies onto the surface. Finally, attach the zip-type bag to the opposite end of the funnel with a rubber band or zip tie to serve as the collection chamber.
Effective Trap Deployment and Placement
Proper placement is key to maximizing the trap’s effectiveness against climbing lanternflies. Traps should be installed on infested host trees, such as the invasive Tree of Heaven (Ailanthus altissima), maples, black walnut, willow, or grapevines. The trap works best on trees with relatively smooth bark, as deeply grooved bark can allow nymphs to crawl underneath the screening skirt.
The ideal installation height is approximately four feet (about one meter) from the ground, often described as chest height. This elevation captures significantly more adult lanternflies than traps placed closer to the base. Secure the screen skirt tightly around the tree trunk using pushpins or a staple gun, avoiding nails or screws that could wound the living tissue beneath the bark.
The goal is to create a tight seal where the screen meets the bark so lanternflies cannot bypass the trap. This strategy takes advantage of the insect’s predictable behavior after being blown down from the canopy or when moving to feed. Trapping is particularly effective during the nymph stages in late spring and early summer, but it continues to catch adults later in the season.
Maintenance, Removal, and Non-Target Safety
Regular inspection is necessary for efficacy and responsible pest management. Check the collection container at least every one to two weeks, or daily during heavy infestations, to prevent clogging. A full trap ceases to function properly, and dead insects degrade quickly, causing an unpleasant odor.
To dispose of captured lanternflies, carefully remove the collection bag and seal the opening quickly to prevent live insects from escaping. The insects can be killed safely by placing the sealed bag in a freezer for at least 48 hours before disposal. Alternately, submerge the contents in a container of soapy water for a similar period before discarding.
While the circle trap is inherently safer than sticky bands, monitor the trap for unintended captures of non-target species. If any small lizard, insect, or other animal is found alive inside the collection chamber, safely release it away from the trap area. To prevent damage to the tree bark or the capture of non-target species during the dormant season, remove all trap components in late fall or early winter.