The spotted lanternfly, Lycorma delicatula, is an invasive planthopper from Asia that has established populations in the United States. This insect poses a threat to various plants, including agricultural crops and trees. Many people observe these insects in large numbers before their apparent disappearance. This article explains the seasonal patterns of spotted lanternflies.
Understanding the Lanternfly Life Cycle
The life cycle of the spotted lanternfly unfolds through distinct stages, beginning with overwintering eggs. These eggs hatch into nymphs, which undergo several developmental changes, known as instars, before reaching adulthood.
The first three nymphal instars are black with white spots. These early-stage nymphs are typically visible from April through July. The fourth nymphal instar is notably different, appearing red with white spots. This stage usually occurs between July and September.
Following the nymphal stages, the insects mature into adults, generally appearing in July and remaining present into the fall. Adult spotted lanternflies are approximately one inch long and half an inch wide, characterized by grayish forewings with black spots and red hindwings with black spots.
The Adult Lanternfly’s Seasonal End
Adult spotted lanternflies typically die off with the onset of colder weather, usually from late fall into early winter. Freezing temperatures are a primary factor in their demise. These insects are not adapted to survive the winter as adults. Their life cycle naturally concludes within a single year.
As temperatures drop, their activity diminishes, and they eventually succumb to the cold. The disappearance of adult spotted lanternflies is a regular seasonal event, marking the end of their active feeding and reproductive period.
Preparing for Next Season: Overwintering Eggs
Although adult spotted lanternflies do not survive the winter, their presence is felt again the following spring through their overwintering eggs. In the fall, adult females lay egg masses containing 30 to 50 eggs. These masses are commonly found on a variety of surfaces, including tree trunks, rocks, outdoor furniture, vehicles, and even firewood.
Newly laid egg masses appear smooth and are often covered with a grayish, mud-like coating, which can initially be waxy and white before turning gray-brown. This protective covering allows the eggs to endure harsh winter conditions. These resilient egg masses hatch in the spring, typically around April, releasing new nymphs and restarting the annual cycle of the spotted lanternfly.