Lantern Fly season is here; are YOU prepared?
Q. Five years ago, Nancy in Flourtown, PA wrote: “I found a colony of tiny black bugs with white dots on my roses. I instinctively squashed them with a gloved hand but did not think to get a picture first and could not id them on Google. I’m hoping they were not beneficial. Can you help me with this?
A. Yes, and I think an update on this pest is long overdue.
Those crazy black and white cartoon dice with legs are the nymph form of the invasive Spotted Lantern Fly. And those funny-looking dots soon turn into monstrous invaders that we must stop from progressing into their adult form.
On individual plants, you can spray them off with sharp streams of water, or saturate them with insecticidal soap or a light horticultural oil designed for use in the summer. (Soaps and oils only work when you spray the pests directly and smother them. There is no ‘residual action’.)
At that time, The Allentown Morning Call reported that if they do reach their colorful (and annoying) adult stage, a new trap had been created that homeowners could either make or purchase.
Spotted lanternfly circle traps, which can be bought online or made at home, are essentially wire mesh wrapped around a tree that guides the upward-climbing young lanternflies into a bag or container, where they get trapped and die.
The circle trap offers homeowners an alternative to sticky tape, which has come under (deserved) fire for also catching birds and mammals. “The circle trap gets us away from that sticky material,” explained Heather Leach, an Extension associate at Penn State, “so you can use it without fear of birds or bats getting stuck.” The insects damage plants by feeding on them and by excreting a sticky-sweet substance called honeydew that attracts ants like mad. They cause damage to trees (especially Tree of Heaven) as well as grapes, apples, hops, stonefruit and other plants. (McGrath here: In my experience, they do the worst damage to grapevines, leading to scarily massive pesticide use that isn’t even very effective.)
People can make their own circle traps with household items. You’ll find details at the Penn State Extension website. We’ll include a direct link to those directions in the written version of this Question of the Week, which you’ll find online at the Gurney’s website.
The traps are effective because lanternfly nymphs — young lanternflies without the signature pink and brown spotted wings — typically feed on the upper parts of trees, fall to the ground and then climb back up.
“It’s almost like a minnow trap for spotted lanternfly. They don’t try to get out, and perish in the trap”, explains Emelie Swackhamer, a Penn State Extension educator.
(The trap works best on the nymphs, so don’t delay if you want to try this.)
Swackhamer prefers trap designs that lead the lanternflies into plastic bags, which you can collect, throw out and replace. “That way, you don’t have to empty out the dead insects, which {quote} get really smelly.”
And now, as promised, a VERY recent update, reported by one of my former stations, the mighty WHYY in Philadelphia:
And we quote: “When the lanternfly first arrived, scientists worried that it had no natural predators. But a decade since its arrival, researchers are discovering that more and more native species are munching on the bug. Penn State professor of entomology Kelli Hoover did a citizen science survey to see if anything was actually eating them. And they were! “We had almost two thousand reports of animals feeding on spotted lanternfly,” says Hoover, adding that “it was incredible how many different species; we got reports of arthropods, spiders, ants, and lots of insects and birds. Many different types of birds were reported to be feeding on them.”
People also reported seeing raccoons, chipmunks, frogs, and even fish eat lanternflies on occasion. What Hoover also discovered is that when lanternflies don’t feed from their preferred Tree of Heaven, they seem more palatable to vertebrates like birds. Animals will feed on lanternfly that have munched on Tree of Heaven sap, but they much prefer those that don’t.
Arthropods, on the other hand— spiders, ants, praying mantis — really don’t seem to care what the spotted lanternfly has eaten.
“Our star predator is something called the spined soldier bug, says Hoover. “They dig their beaks into the pest and suck all the juices out.”
(McGrath again: Spined Soldier bugs resemble stink bugs—so look up the differences and think twice before you squish.)
Hoover has also found increasing numbers of eggs from the Carolina Mantis, Chinese mantis, and wheel bugs in areas of heavy lanternfly infestation. “When the lantern flies start hatching, the predators go right after them.”
Hoover’s current research is honing in on what seems to be their biggest predator--the spined soldier bug. “She asks: Do the bugs increase their rate of predation when the lanternfly populations increase? If so, the bugs could be key to controlling the spotted lanternfly population naturally; they could be released to help control the lanternflies in vineyards.”
Vineyards are the most vulnerable to lanternfly infestations, and have suffered the most economic damage, says Flor Acevedo, (assay-vedo) assistant professor of entomology at Penn State. (The most resilient vine, the one lanternflies do not do well after feeding on, is the native muscadine grape.)
“Remember when we had the brown marmorated stink bug come into Pennsylvania, and it was a serious problem for many, many crops,” Hoover recalls. “But after about 10 years, natural enemies were feeding on them, and now they’re pretty well managed.”
