During the past two weeks, some New Jerseyans (including some of my co-workers) have reported seeing pesky spotted lanternflies in their yards. But their descriptions varied widely.
Some saw tiny nymphs that are black with white spots. Some saw nymphs that are bright red with black and white blotches. And others saw larger lanternflies with colorful wings.
Have different species of spotted lanternflies invaded the eastern U.S.?
The answer is a big no, according to several insect experts in New Jersey and Pennsylvania. They say July happens to be a rare month in the one-year life cycle of spotted lanternflies, because these bugs can be going through different phases of their lives at slightly different paces.
Lauren Bonus, an entomologist who heads the Camden County Mosquito Commission, said the life cycle of spotted lanternflies tends to be consistent from one phase to the next, but “July is the one month where they all have the possibility of overlapping.”
Since every spotted lanternfly doesn’t hatch from its egg on the same exact day, during the same week or even in the same month, each lanternfly won’t go through its nymph phases and adult phase at the same time, Bonus explained.
Most spotted lanternflies begin to emerge from egg masses in May, Bonus said. “But some emerge in April, and some emerge in June.”
When they hatch will determine when they reach their first nymph phase (also known as “first instar”), their second nymph phase, their third nymph phase, their fourth nymph phase and — finally — their adult phase. And these pesky critters will look different in each of those phases.
This graphic shows the annual life cycle of the spotted lanternfly.Camden County Mosquito Commission
When these insects first emerge — typically in April, May or June — they will be very tiny with black bodies and white spots. During their second and third phases, usually in June and July, their colors will remain the same but the lanternflies will be slightly bigger.
The fourth phase, known as fourth instar, can occur anytime between July and September, and this is when the lanternflies will have mostly red bodies with slightly larger white spots and black blotches.
The adult phase — the one where the lanternflies grow larger and sport colorful wings — can also start as early as July or as late as December, depending on how cold it is outside. In New Jersey, the adult phase typically starts in July and August, Bonus said.
By this time of the year, ”they’re all on their way to (becoming) adults,” she said. “By September, all of them should be in their adult phase.”
Once they reach their adult stage, the lanternflies begin to mate and lay eggs — setting the stage for new batches of nymphs next spring. (The adults will die off during the first hard freeze of winter, but most of their egg masses will survive.)
These are the three different looks of spotted lanternflies as they age. The black-and-white phase at left is what this bug typically looks like after hatching in the spring. (Photos from Penn State Extension)
Amy Korman, horticulture extension educator for the Penn State Extension in Northampton and Lehigh counties in Pennsylvania, agrees it’s common to see spotted lanternflies in different phases around your home in late July.
“Right now, it’s not unusual to see a mix of black and white nymphs, red nymphs, and adults,” Korman said in an email. “By September, it will be almost all adults. Bottom line, they are not all in sync.”
Whether they are in sync, or not, spotted lanternflies can damage many varieties of trees, shrubs and ornamental plants, according to bug experts at Rutgers University. The lanternfly’s main target is the Ailanthus, a fast-growing tree that is commonly known as the Tree of Heaven.
These insects also tend to prey on red maple trees, black walnut trees, willow trees and grapevines, posing a threat to the wine industry.
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Len Melisurgo may be reached at LMelisurgo@njadvancemedia.com.