Spotted Lanternflies enter egg-laying season across the river towns

Spotted lanternflies are in their adult stage now along the river towns, from Kingston and Port Ewen up through Saugerties, across the river in Red Hook, Rhinebeck and Tivoli, and up into the Catskills at Palenville and Woodstock.¹ The adult (Lycorma delicatula) is about an inch long with gray forewings speckled black. When it jumps, the hindwings flash red with black spots and a white band. Most people meet it first on a house wall, a car door, or the trunk of a tree-of-heaven along a road.

Spotted lanternflies follow a set life cycle in general: eggs hatch in spring, nymphs pass through four stages (black with white spots, then red), and adults typically emerge by mid-summer, with mating beginning in late summer. That puts the population here now in the egg-laying phase, which runs from now until the first killing freeze, likely mid-to-late October in this area. Each female lays one or two masses of 30 to 60 eggs and coats them in a putty-like layer that starts creamy white, dries to pinkish gray, then darkens and cracks until it looks like a smear of dried mud. On a tree, most masses end up ten feet or more above the ground. But they go on almost any smooth surface: rock, a fence post, split firewood, the side of a trailer.

That last habit is how the insect travels. Adults are poor fliers. They walk and jump and cover a few miles at most in a lifetime. The long moves happen when egg masses ride on vehicles and firewood, and the places they are turning up this month fit that: riverfront streets, road corridors, a fairgrounds, a college campus, rather than deep forest.

Both nymphs and adults feed by piercing bark with needle-like stylets and drawing sap from the phloem, the inner bark. Tree-of-heaven, itself an introduced tree from the same part of Asia, is the host on which they survive best and lay the most eggs, and it is thick in Kingston, where it was recorded again this week.¹ Where dozens crowd one trunk, the bark weeps sap and the insects rain sugary honeydew onto everything below. The honeydew grows a black sooty mold and draws yellowjackets and ants. Trees rarely die from the feeding; they are stressed by it. Grapevines are the exception. Heavy feeding can cut yields drastically and kill vines outright. Wild riverbank, summer and fox grapes were all logged around Red Hook and Rhinebeck in the past two weeks, and the valley's vineyards are the one crop with real losses on the line.¹

Native animals have started eating them. Cardinals, catbirds, blue jays and tufted titmice all take adults, as do praying mantids, wheel bugs, orbweaver spiders and spined soldier bugs. None of these predators came over with the insect. Researchers have also proposed that lanternflies feeding on tree-of-heaven may store its bitter compounds, potentially making them less palatable to some predators — a hypothesis still being tested, not a confirmed effect on their numbers.

Dutchess and Ulster are both counties where the state considers the insect established.¹ The DEC's ask is plain: kill adults on sight, scrape egg masses into a bucket of hot soapy water or a bag of hand sanitizer, and check vehicles, firewood and outdoor gear before moving them, especially when leaving an area where lanternflies are thick. Reports of specific locations are still welcome through iMapInvasives. From here until the first hard frost is the window when scraping an egg mass removes up to sixty of next year's nymphs at once.