The spotted lanternfly (Lycorma delicatula) is an invasive planthopper species native to Asia, first detected in the United States in Pennsylvania in 2014. This insect poses a significant threat to agriculture and forestry due to its wide range of host plants, including grapevines, hops, and various hardwoods. Understanding the duration of its single annual life cycle is paramount for effective pest management strategies. Knowing the exact timing of each phase helps researchers and homeowners target the pest during its most vulnerable life stages.
The Overwintering Egg Stage
The annual life cycle of the spotted lanternfly begins in the fall when the adult females lay their eggs, which then become the only stage to survive the winter months. Females deposit one or two egg masses, each containing 30 to 60 eggs arranged in neat rows. To protect them, the female covers the eggs with a secretion that starts as a creamy white, putty-like substance. This protective layer quickly dries and hardens, taking on a gray or pinkish-tan color that resembles dried mud or cement.
This camouflage allows the egg masses to blend seamlessly with the surfaces they are laid on, such as tree bark, rocks, outdoor furniture, or vehicles. The egg stage is the longest, dormant phase of the lanternfly’s life, starting in September and lasting through the winter until the following spring. Hatching typically begins in late April or early May and continues through June, when the ambient temperatures are consistently warm enough to trigger development.
The Nymph Stages of Development
Once the temperatures rise, the eggs hatch into the nymph stage, which is characterized by four distinct developmental phases, or instars, lasting approximately 10 to 12 weeks in total. The first three instars, active from May through July, are small, wingless, and entirely black with bright white spots, sometimes leading to confusion with ticks or spiders.
A significant physical change occurs when the insect enters its fourth and final instar, typically starting in July and lasting through mid-August. At this point, the nymph develops striking patches of bright red along with the existing black and white spots, growing noticeably larger to about a half-inch in length. This rapid growth phase is characterized by intense feeding as the nymph prepares for its final molt into the adult form.
The Adult Lifespan and Decline
The transition to the adult stage begins in mid-to-late July, marking the start of the longest and most destructive phase of the lanternfly’s active life. Newly emerged adults are immediately recognizable by their large size and tent-like wings, which are a dull pinkish-tan or gray color covered in black spots. When startled or in flight, the adults reveal their vibrant hindwings, which are a highly visible combination of bright red, black, and white.
This adult phase is the reproductive stage, living for about three to five months. Adults remain active through the late summer and fall, with mating and egg-laying occurring from September until the onset of winter. The population’s end is determined by the weather, as adults cannot survive freezing temperatures. The first hard frost, typically occurring between late November and early December, eliminates all remaining adults and nymphs, completing the annual cycle and leaving only the newly laid eggs to overwinter.