Wednesday, July 16, 2025

THE SPOTTED LANTERN FLY IS HERE..IT’S AN INVASIVE, BUT NO NEED TO GO “BALLISTIC”!

We have a new Chinese invader! No not a human-engineered deadly virus, but a gentle little “ladybug-look alike”! It’s a plant leafhopper known as the Spotted Lantern Fly (Lycorma delicatula). Though the Spotted Lantern Fly (SLF) looks like the a spot dabbed ladybug, it is unrelated to this species. It belongs to the Order of “true bugs” or Order Hemiptera—(the “half winged” bugs).  This group of insects have two pair of wings, with the forewings (outside pair) being half-leathery at their base, with a membranous type of structure on the distal ends of the wings. Thus, in the case of the SLF the adult’s gray forewings permit the red color of the underwing to show through, giving a reddish cast to the insect’s wings at rest. 


This new invasive species, a native of Vietnam and China is associated with another unpleasant invasive Asian species—the so called  “Tree of Heaven” (Ailanthus altissima) which is claimed to be the primary host tree of SLF.  (A.altissima is locally known as a “Stink Tree” based on the unpleasant scent of its leaves…which look a bit like those of the native Black Walnut tree). However, and unfortunately, the SLF is known to attack other trees and vines as well. 


Farmers and orchardists are particularly concerned about the species tendency to attack soybeans, grapes, stone fruits (i.e. plums ) as well as apples. SLF larvae suck plant fluids and produce a substance called “honeydew”which may accumulate on the host plant and can foster growths of fungus and other plant diseases.  So far the threat of economic impact to farms, vineyards and orchards has not materialized or been evaluated, but the SLH has only been here since 2014.  (But see Notes below)


This colorful, red and black hopper or “SLF” goes through four distinct stages of development. In the early spring the SLF emerges as a tiny little (0.5 cm long) black jumping beetle with white spots, which over a month or more morphs through three growth stages growing larger to about 1 cm long and changes color patterns. The early “black bug” stage finally becomes a black-legged, red-backed “bug” with prominent white spots. Its bright colors make it quite attractive in these early stages. And like all insects of this group ultimately metamorphose into the very colorful and attractive adult Spotted Lantern Fly.  The black legged, white spotted specimens seen on 7/15/25 were observed clasping onto young wild grape vine shoots. It was noted that the host plants (Fox Grape) were not altered by the bugs presence, the leaves tendrils and other pars seeming as turgid and lively as surrounding plants of the same species with no bugs.   


It is noteworthy that all the instars have  large powerful rear legs, and assume jumping posture with their rear bodies lower than their foreparts, which may assist it in high jumping. Its jumping abilities are equal or better than those of a common grasshopper. I observed several specimens jump at least 50 cm or more, or at least as much as 100 times their own body length.   When disturbed on a branch, they first tend to move so as to place the branch between them and the intruder. They also appear to avoid sprays by moving up the branch to higher elevations. If the intruder persists they readily jump and disappear among other foliage. Observed on the ground, where they might be stomped by foot—as is directed by some experts for these bugs—one finds their reaction time too fast for the average human foot. They often easily escape such attempts.


The adult Lanternfly is an overall gray with faint darker spots often visible. It is about 2.5cm (an inch) long with black legs and head, a brown or gray cicada like body and two sets of wings. The over-wings, half leathery, half membranous  are gray with black spots  while the under or secondary wings are more colorful with red and gray areas. The color of the underwings show through the forewings. It is the adult which lays its eggs masses often on the Tree of Heaven,  which is its main host. 


The Tree of Heaven is also an unwanted invader from Asia.  Adults leave egg masses on other trees as well, and other other surfaces. Egg masses (tan or brownish elongate patches or smears) are often found on trees, automobiles, woodpiles and lawn furniture.  The spread of SLH from China and Vietnam to Japan (2000) the USA (2014) and other nations has been no doubt related to the possibility of transmission of egg masses adhering to transport vehicles, containers or box and cartons. The massive China trade in such containers may have been one way in which egg masses may have been so widely dispersed by this insect. 

 

On July 15, 2025, during a half-mile (0.85 km) walk along Brookhaven Town’s “Rail Path”, in Brookhaven, Suffolk County, New York, (40.94290 N, 72.99430W ) this author observed four (4) sites of Spotted Lantern Fly infestation. All “infestations” (sites where species was observed) occurred on the young shoots of the wild Fox Grape (Vitus labrusca) which is common along the margins of this walk/bicycle path. 


Each site had from several instars to a dozen or more clustered along the new grape vine shoots.  In addition, I recorded two 4th stage instars on the asphalt surface of the path. I attempted to kill them (by foot) but was unsuccessful each time. Their reaction time to such blunt force attacks is rapid, about  equivalent to that of a common house fly (Musca domesticus) so I failed to reduce their population by this means on the Rail Path. 


The SLF is not a threat to humans, since it does not sting or bite, is not venomous, or carry human diseases. It is claimed to be a threat to agriculture viticulture and perhaps forestry.  Since the new “invader bug” is basically harmless to humans it seems unwise to use the presence of a few of these insects in your garden or yard as a reason to begin spraying dangerous and counterproductive  pesticides.  Some major stores continue to irresponsibly sell dangerous pesticides like “Roundup” and some purchasers responding to irrational fear will spray these dangerous chemicals that are many times more of a threat than the tiny harmless bug it will kill.


  And the natural “bug fear” humans have will no doubt be taken advantage of by “bug spray” entrepreneurs who will gladly offer “professionals” to spray toxic pesticides that kill all insects as well as the birds that feed on insects. So don’t go “ballistic” on the SLF!  


There are other alternatives. Diatomaceous Earth is non toxic.  It is reported to be effective when uses as a spray (1 tbs per gallon of water).  There are other options as well. 


As in normal population dynamics, in some time, natural insect predators and insectivorous birds will eventially control the population of the SLF.  The  NY State Department of Agriculture recommend you report all sighting to help reduce spread of the bug.   Also sightings  of the insect should be reported by email to:  spottedlanternfly@agriculture.ny.gov, or In NYC email: Forest.Health@parks.nyc.gov.



Black Walnut Tree Infested


Besides the infestation noted above, recent observations revealed an infestation of this species at my home property on Long Island, NY. There, I discovered two young walnut trees I had planted several years ago were heavily infested. Four or fivet

 lower branches of the  Eastern Black Walnut (Juglans nigra) were found to be infested with a mixture of SLF instars most in the last (red back white dots) stages (This in mid July) of development. Each branch may have had 20 or more individuals. 


Having no contact insecticides, I tried to use a spray of white enamel spray paint. I was able to coat about half of the clustered instars on one branch with white enamel spray paint. They fell to the ground below the tree. As the enamel paint dried those fully sprayed seemed disoriented and disappeared into the undergrowth. A spray can of carburetor cleaning agent (main ingredient acetone) caused a rapid avoidance reaction. Some fell from the tree branch they moved off rapidly and were not seen again. I suspect the acetone spray may have killed them, but there was no evidence of this. A spray can of “Deep Forest Off” did encourage rapid avoidance …but I suspect may not have any effect on their survival. Oddly, the spray of white enamel paint seemed to be most effective…but a bit too messy, particularly in the close quarters under the Walnut tree.  I also made use of a spray of foaming bleach cleanse (main ingredient Hypochlorite solution). If the bug was completely covered it did cause death. But this outcome occurred only in two instances.


Update: -

I observed  the SLF as a mix of instars of various ages attached to the small diameter distal tree limbs, here on LI, NY.  The infested trees were mostly Black Walnut trees. Black Walnut (Juglans nigra)) looks similar n leaf structure and overall tree shape to the Chinese native host tree, the Tree of Heaven (Ailantus altissima) but are not remotely related. Is it a “visual” attraction?  

Near 4839 Nesconset Hyw Port Jefferson Station NY  at: 40..91714N 73.05376 W  I observed a Tree of Heaven (Ailanthus sp) infested with SLF.  Sseverl tree limbs I was able to observe had a smattering of early and late instars. I also observed one mature adult on this same tree.
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Near 18 Victory Knoll Path, Miller Place, NY at: 40.94979 N, 73.00557 W I observed a Black ] tree (about 6 inches BHD) heavily infected with instars of various ages. 

August 3, 2025
Returning to the site where I first observed SLF July 15, 2025 on the Brookhaven Rail Path (noted above) I found no SLF instars on the formerly infested Fox Grape. However, I did find a single adult SLF on the Fox Grape vine I had observed at an earlier date.  Fox Grape leaves, branches and tendrils all seemed unaltered. Deer browse on Fox Grape ands some of the branches showed ;evidence of browsing…but no evidence of alterations as a result of SLF at least to a casual observer. 

August 6, 2025
Casual observations on a 1 mile walk along the Brookhaven Town Bicycle Path resulted in the  observation of  SLF adults and late stage instars. Total number observed: 8 adults, 5 L stage instars in three sites. All, but one were found on Fox Grape or Tree of Heaven foliage (i.e. small diameter (@0.5 cm) branches or tendrils. The Tree of Heaven sapling (about 6 ft tall) had 5 adults and 3 instars. Interestingly it was heavily browsed by deer (a species not observed to be browsed by deer) One adult was observed on a Russian Olive (Elaeagnus angustifolia) tree/bush. 

On the same date: I observed limp, yellowing leaves on a neighbors domestic fig tree (Ficus carica—var. “Turkey Fig”). Investigating the cause, I  found several SLF late stage (red) instars sucking fig juices on the limp branch. So they do impact Fig trees as well.

Trying to stamp out a Spotted Lantern Fly (SLF) adult?  Your shoe pushes a wave of air in the direction of the SLF as the sole of the shoe descends on its target. The SLF is an excellent jumper!  As the deadly leather (or rubber) sole descends, it pushes a puff of air ahead of it, the SLF reacts to the threat and jumps into the air. This air —is being driven by the solid shoe behind it— and with its powerful jump and the help of the moving air—in a split second, the fly escapes the crush of leather  and lives to lay its eggs on some tree, pile of wood, or garden furniture. A fly swatter works better…it has holes which let the moving air flow through it…No puff of air to help the SLF escape! But who carries a fly swatter with them?g

The instar and adult SLF both have powerful rear legs which can launch it into the air to escape a threat. If you carefully observe its head vs tail end, you can change the odds a bit to achieve a successful SLF obliteration.  If you launch your shoe attack by observing the orientation of the bug, then rotate the attack so your the raised toe of the shoe is launched toward the head of the insect rather than the tail end!  The puff of air from the shoe tends to offset the very  effective jumping capability of the bug.  It works!—- Good luck….! 

August 25,2025

Observed today a in the vicinity of a Yellow Jacket Wasp (most likely Vespula maculifrons ) underground nest, I observed aYellow Jacket Wasp (YJW) attacking a Spotted Lantern Fly adult. The wasp held the head of the SLF with its mouthparts as the seeming alive SLF appeared to struggle to escape. Was the SLF moving in response to the actions of the wasp or was it recently dead, and carrion? Or was the encounter of the wasp attacking living prey?  I was not able to decide. 

The SLF was intact, and was located within a meter of the busy underground wasp nest where YJWs were patrolling aerially.  Will YJWs have an impact on the SLF population?  Possibly.  In late summer this wasp does seek out insects as prey and other sources of protein, living as carrion feeder to provide nutrients  to its pupae in the colony”s nest.  Predation of Vespula on SLF, however, does not seem a likely “sole” solution to the burgeoning population of SLF. 

Update September 29, 2025
The areas which I describe above as having concentration of SLF larvae were revisited on this date. I observed SlF adults (three observed) on the vines of a Fox Grape. The general description of the status of  vegetation suggested signs of disease to the eye of a non-professional plant disease specialist. Fox Grape vines did not look thrifty. They bore no fruit—though there was little fruit observed on other uninfected grape as well. The mature leaves of the Grape were heavily spotted with what I assume is some form of plant disease. Associated  Black Cherry small tree appeared to have almost all of its leaves also spotted. Similar patterns did not appear in other areas where few or no SLF were observed earlier in the season. 
Did they cause the observed effects….? Not sure. 

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