DIY Spotted Lantern Fly Trap Plans

These posts will help you take the items in the pic, make a reusable spotted lantern fly trap (SLF), and install it on a tree. The trap is not put on in a way that will harm the tree. It’s easily cleaned out when full and then be set back up. It is easy to take down once the weather has turned cold for the winter and all the SLFs have died off.

The way this trap works is to let the SLFs climb up but only so far and they get stopped by the screen tightly tied shut at the top of the trap. They need to get higher up the tree to the smaller branches they can bite into and suck out the fluids they need. Without that, they just dry up and die if they don’t get out of the trap. It usually takes no more than a day for them to dry out and die.

The screen holds the SLFs in. Birds don’t get caught up in it. Occasionally wasps or maybe a praying mantis or spider gets up in there. It withstands the rain just fine, and I’m using last year’s wood to reassemble the traps for this year. The screen is tied up at the top so it is easy to take it down to clean out the trap if it gets too crowded to let new SLFs crawl up and get trapped. There can be hundreds of those things crawling up in there, and I had one tree that needed its trap cleaned out 3 times last year.

Materials:

• Zip ties (enough strung together to go around the tree)
• 4 small angle brackets to support the bottom tray
• Duct tape to hold things together
• Insect screen, the flexible nylon stuff
• Scissors
• String or thin rope to tie up the screen above the tray
• Staple gun and at least ¼” staples that can go into plywood
• 1/2” exterior plywood (actually 15/32”) Nothing fancy here, just the rough exterior grade plywood. Doesn’t have to be coated.
• Jigsaw (or some way to cut out a curved piece of plywood)

Step 1: Get the trunk’s circumference and calculate the inner and outer diameters (I'm putting it in terms for school kids so please put up with the simplified language)

Measure the circumference of the tree at the point where the trap will go around. I usually go with a good place well below the first big branch or about 3 ft. up the trunk. There needs to be some tree trunk above the tray without branches sticking out for the screen to wrap around.

Take that number (say, 20” around the trunk) and divide by pi to get the trunk’s diameter. Hopefully, it is roughly circular. If not, you may need to do some creative cutting to make the tray fit the trunk.

Circumference = Diameter X pi           So for this case it goes like this:

Circumference ÷ 3.14 = Diameter --> 20” ÷ 3.14 = 6.4” Diameter (roughly)

The tray goes around the trunk but needs to be wide enough to leave a gap so the SLFs can crawl up the trunk past it. Add 1.5” to the diameter you got so that there is roughly three-quarters of an inch clearance around the trunk. It doesn’t have to be elegant or exact (the SLFs really don’t care), just enough to let them go up but not too much wider because some of them do try to climb back down. Not as many as you might think though.

That’s the inner circle. In this case, it will have a diameter of about 8” (6.4” + 1.5” = 7.9” and well, 8” is easier to work with). Make sure you leave room for another 5-6” longer diameter because that will be the second, outer circle.

Step 2: Draw your tray onto the plywood

Draw the circles on a piece of plywood. If you don’t have a compass, just measure out from the center point the distance of the radius (half the diameter) and mark enough points to give you a guide to draw the circle. For this trap, the short radius will be 4” for the inner circle and 7” for the outer circle’s longer radius. The tray will be about 3” wide all around.

Step 3: Cut out the two semi-circles for the tray pieces

Draw a square on the wood that just fits the outer circle inside it and cut out that square of plywood. Now cut that square in half. I cut it in half on the diagonal so the saw can start cutting more easily at a right angle for 2 of the 3 cuts. Cut out the two pieces of wood that will form the tray when put together around the tree. I used a jig saw but a miter saw or an old fashioned hand saw will work for a rough circle. Last year they were left square and that made it awkward and wasteful when trying to wrap the screen around the tray.

Step 4: Attach the tray supports (Zip-ties and angle brackets)

Select the place on the tree the tray will be and wrap it with Zip-ties that may have to be daisy chained to be long enough to wrap around. Don’t pull it tight yet. Leave enough slack to insert the 4 angle brackets spaced evenly around the trunk. Then pull the Zip-ties snug. See? No nails or screws in the tree to cause it harm and this is quickly removed with a snip of the Zip-tie when it comes time to take it down..

Step 5: Put the two tray halves around the tree to make a circle resting on the support

Tape them together well at the seams and then tape them to the angle brackets. I found it is best to have each seam resting right on a bracket for stability. Tape the hell out of where the seams and the bracket come together. Make sure to keep the space around the trunk clear for the SLFs to climb up through.

Step 6: Measure out the screen needed to go around the tray.

Have a couple inches of overlap. I found it easier to hold the top of the screen and wrap i t around the tray to get a rough guide. Mark the spot and then use a straight edge as a guide to cut the screen with the scissors. Since the traps I’ve been setting up are on trees next to a sidewalk, there’s always one handy.

Step 7: Attach the insect screen to the tray

Attach the screen to the underside of the tray all the way around leaving no gap to let SLFs push their way out the bottom. I use the staple gun to tack it in place from the bottom of the tray. Duct tape could work but with the tray only being so wide, it would be difficult to do. Plus, rain and heat may eventually cause the tape to fail.

Step 8: Tie the screen around the trunk above the trap.

Loosely tie the rope around the trunk above the tray with a slip knot to start. Slip the screen up under the rope and fold it over so there’s an overlap of 4-5 inches in case it needs adjusting like tying the rope higher later on. I use flexible nylon screen that is 36” wide. Don’t make it too tall without an overlap because SLFs don’t always crawl up from the ground. They can fly short distances and can land on the screen and just crawl up the outside of it. Having a good overlap will catch a lot of those, too. Tighten the rope and adjust the screen around the trunk so it’s loose. It only has to be sealed tight at the top and onto the tray so the SLFs cannot escape.

Since the SLFs often get up and over the trap I also use a BugBarrier Tree Band.

https://treebands.com/home

Using that alone was what I started with for the maple tree I take care of at the church. However, that thing soon got saturated with SLFs and it was still August. It’s expensive and we couldn’t afford to keep replacing it. That’s why I began to make DIY trap experiments until I found a design that works well. Now the BugBarrier catches most of the ones that get over the trap.

SLFs will still fly up into the tree instead of crawl up. You can knock them out of the tree with a long pole and then they’ll crawl up and get trapped.

Don’t try that right after it rains though. Uhh, a friend told me.

PeterWick said:

Step 1: Get the trunk’s circumference and calculate the inner and outer diameters (I'm putting it in terms for school kids so please put up with the simplified language)

Measure the circumference of the tree at the point where the trap will go around. I usually go with a good place well below the first big branch or about 3 ft. up the trunk. There needs to be some tree trunk above the tray without branches sticking out for the screen to wrap around.

Take that number (say, 20” around the trunk) and divide by pi to get the trunk’s diameter. Hopefully, it is roughly circular. If not, you may need to do some creative cutting to make the tray fit the trunk.

Circumference = Diameter X pi           So for this case it goes like this:

Circumference ÷ 3.14 = Diameter --> 20” ÷ 3.14 = 6.4” Diameter (roughly)

The tray goes around the trunk but needs to be wide enough to leave a gap so the SLFs can crawl up the trunk past it. Add 1.5” to the diameter you got so that there is roughly three-quarters of an inch clearance around the trunk. It doesn’t have to be elegant or exact (the SLFs really don’t care), just enough to let them go up but not too much wider because some of them do try to climb back down. Not as many as you might think though.

That’s the inner circle. In this case, it will have a diameter of about 8” (6.4” + 1.5” = 7.9” and well, 8” is easier to work with). Make sure you leave room for another 5-6” longer diameter because that will be the second, outer circle.

Are you just putting traps on Trees of Life? or other trees, too?
My problem is, the Tree of Life I have a problem with is not mine or on my property.  (sigh)

Juniemoon said:

Are you just putting traps on Trees of Life? or other trees, too?
My problem is, the Tree of Life I have a problem with is not mine or on my property.  (sigh)

I would get a spray can of hornet and wasp killer, and just spray the tree. That concoction of pinesol is useless. If you can see them on the car or ground, get an empty plastic juice bottle ( I use simply fruit juices), take the cap off and just gently place the open bottle close to the critter… they jump right in. I have caught many more doing this. 

Juniemoon said:

Are you just putting traps on Trees of Life? or other trees, too?
My problem is, the Tree of Life I have a problem with is not mine or on my property.  (sigh)

Unless the tree of life is huuuuge, it’s trunk might not be able to support this thing. I’ve put this on maples and a couple fruit trees. I still should come over and take a look at your situation. PM me. 

Jaytee said:

I would get a spray can of hornet and wasp killer, and just spray the tree. That concoction of pinesol is useless. If you can see them on the car or ground, get an empty plastic juice bottle ( I use simply fruit juices), take the cap off and just gently place the open bottle close to the critter… they jump right in. I have caught many more doing this. 

This process started last year with a tree that was mobbed with them daily. It's near Taylor Park and the river that goes through it. The end of the park by Rector/Ridgewood & Main has several tree of heaven clusters so there's a seemingly endless supply. When this happens, you need a trap that can always be there.

This pic was from an earlier point when I'd removed the sticky-side-out tape that was open to anything that would land on it. I didn't want to snag birds, so I tried to make a platform with tape around it to catch them. Then I saw the BugBarrier things around town and tried that. When that kept getting filled up I did more experiments.

My wife is a big fan of Smart Water so I use these things as manual traps. Cut off the top where it tapers to the cap and you have a wide open mouth for them to jump in. It's long so you can reach more of them. I roll up duct tape into sticky-side-out tubes and put some down inside. The SLFs get stuck on the tape when they jump in. They get filled up quickly though with the trees I work on but it's easy to make more.

We also wanted something that would do some killing when we weren't there.

The bug sprays I've tried work okay, sort of, when sprayed on the SLFs but when the spray is on the bark already and dried up, they crawl right over it undeterred.

The insecticidal soaps and neem oil also work directly on them, but once that stuff dries, they can crawl over it. Spraying those things up onto the branches with leaves where you might see them can work but before we knew it, we were hurting the leaves just like the "honeydew" the SLFs excrete. The pores on the leaves would get clogged and wither. We were afraid that we were killing the trees.

ATTENTION!!   to those of us dealing with Spotted Lantern Fly Infestations:

This stuff is more serious than I thought -- Not just perhaps having to remove a dead tree -- but billions of dollars in lost vegetable and fruit crops! 

I uncovered some important information I wanted to share with those of you in the same mess:

First, this article I found from the Mendham Garden Center pointed to a few things I didn't know:  The New Jersey Department of Agriculture is supposed to be set up with representatives who may even come to your home to help you deal with it:

SLF infestations SHOULD be reported to the New Jersey Department of Agricultural.  If you call them and nail down the situation you're in, they may send someone from their staff out to you to evaluate the situation (the more than can be determined over the phone, the less likely their representative will make an unnecessary trip.  Here's what they say at the Garden Center:

As soon as you spot an infestation of the spotted lanternfly in your yard, you should contact the Department of Agriculture (DOA) in New Jersey to let them know. They will send a representative to investigate, and if the infestation is confirmed, they will take all steps necessary to remove the insects and any eggs which may be present.

Generally, the New Jersey DOA will require some kind of information or documentation which makes it likely that these flies are present. A quick phone call to New Jersey’s Department of Agriculture will tell you what kind of information they require so that a trip to your house isn’t wasted

And on the NJ DOA site I found this contact information:

Do you need to report lantern flies in NJ)? Residents are asked to report sightings by calling the New Jersey Spotted Lanternfly hotline, 833-223-2840 (BAD-BUGO), and leaving a message with their contact information and details of the sightings, or by emailing Spotted Lanternfly Control.

Imagine, the government coming to our aid to fix a BUG PROBLEM:  Who'da thunk????

If ANYONE HAS USED, TRIED TO USE, OR PLANS TO MAKE USE OF THIS SERVICE, PLEASE KEEP US POSTED!

After installing a few more of these, I should reiterate the point about things not having to be perfect. It turns out that many tree trunks are NOT circular. Heh heh. That has meant making some impromptu adjustments to the plywood trays rather than just starting over. That has meant patching the hell out of some of them.

Who was it that said if the Egyptians had duct tape, The Sphinx would still have a nose?

Peter:  Can't help but wonder if this ìs anything like what the DOA may have available to help us.  Not having the tools and supplies  available to me or your DIY experience (not to mention my problem trees are not even on my property) would all keep me from taking this on -- though I now know it must be done and admire your talent & ambition for doing so. 

The DOA may even have encountered the "property line" issue before and have come up with a solution (e.g., a letter from them with a directive or an offer to help solve the problem may be more effective than my neighborly suggestion that the bugs in their trees may someday be the cause of the end of life as we know it in North America...in addition to making my car and many I other cars into sticky, ugly messes all fall.

I'm gonna try giving the hotline a call today & see how far I get.  It's possible the DOA has reps sitting around with nothing to do because no one's calling to let them know the seriousness of the problem.

Will keep you posted.

It’s worth a try. I wonder if it will take serious damage to treasured crops such as grapes and hops before real action is taken. I wonder if the maple syrup trade will be hit hard over the SLFs get into New England to a greater extent. 

And so it begins. 

PeterWick said:

It’s worth a try. I wonder if it will take serious damage to treasured crops such as grapes and hops before real action is taken. I wonder if the maple syrup trade will be hit hard when the SLFs get into New England to a greater extent. 

Okay, so who here has stomped on a SLF (or a dozen) this weekend???

The more I learn about these evil varmints, the more effort I want to put into ridding the world of them.  But my situation is impossibly tricky.  I think the best I can hope for is my landlord agrees to give me a different parking space that won't expose my car to the omnipresent sticky goo they leave below them -- IOWs, all over my car.  I have been putting the cheap car cover I got from TEMU on my car at night and taping it down in spots to keep it from blowing away.  It's full of holes, but better than nothing.  But I'm home during the day and use the car throughout, so it must go on and off a couple of times a day.  But it's proved to be better than nothing, and I ordered a couple more from TEMU today.

I realize that since the affected trees are on someone else's property, there may not be much I can accomplish.  But these things ARE CURRENTLY QUARANTINED in the entire state of New Jersey, which means building materials, cars, motors cycles and other things coming into the state should be inspected by the owners to seek out and destroy any visible egg sacs, kill any live flies, BAG any evidence of them in ZIP LOC bags, and then go safely into the garbage.  (One MORE reason to not leave your car windows open at night.)  Trash workers are probably inadvertently spreading them-- as they move cans of trash that may contain egg sacs or adults -- not in zip loc bags and still able to reproduce -- not been properly disposed of.

What I've learned over the last few days is that these insects are much more than a nuisance with what they leave on my car -- they are a threat to our food supply -- destroying grape vines, fruit trees, nut trees and more.  Tomorrow I'm going to take pictures of the leaves on the trees around my parking lot that are showing damage -- discolored leaves that are curling up on themselves, an indication that the trees are already dying.
It may be the best I can hope for that someone should be responsible for removing at least the branches that hang over the fence above the cars parked on our property -- be that our landlord or the tree owners.  We have Trees of Heaven that line almost the entire length of the lot -- on the side that most of the PARKING SPOTS are on.  As much as I'd like to not get sticky opening my car door and having to wash my own car twice a week, I'm aware that any spot the landlord might deign to move me to would be a lot farther from my front door than the one I have now.

JEEZ -- some of these look as big as guinea pigs in these pics!

PeterWick said:

And so it begins. 

I did use my iPhone 14’s camera to zoom in. Then I cropped the photos. Please don’t have nightmares