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Easy beetle trap

Those of you plagued with green fig beetles, aka green June beetles, may find this easy-to-build trap useful. I found the basic idea online but thought step-by-step directions might be helpful:

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1. Cut both ends from a 2-liter soda bottle, creating a funnel. The "neck" hole needs to be big enough that beetles can easily fall through.

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2. Make a plastic baffle that fits snugly into the soda bottle. I cut two rectangles from a plastic ice cream tub, with a narrow slit halfway up the center of each so they could fit together in an "X" shape.  One of the online sources said traps with bright colors at the top worked best, so I painted some decoy "fruit" dots in different colors. I don't know if it really helps, but it might!

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  3. Using the wide end of the soda bottle funnel as a guide, use a Sharpie to draw a rough circle around the neck of a gallon milk jug--avoiding the handle. Then cut the circle out with scissors, taking care to stay inside your line far enough that the soda bottle will fit snugly into the hole. It doesn't need to be perfectly round--the bottle will conform to the shape. Then cut a couple of narrow slits in the sides of the milk jug, about 1-2 inches up from the bottom. These will allow rainwater to drain out.

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4. The critical part is what to use as bait. In years past, I've tried similar traps with no success--using over-ripe fruit that beetles had already been eating. The online source I read recommended isopropyl  alcohol, with some grape juice mixed in. Rather than pour it into the bottom of the jug, put it in a small container with a hole drilled in the lid for a wick. I used a pill bottle with a rolled up a paper napkin for a wick. To keep it from falling  over, I stuck it in the lid of a spray can, which I snipped into a daisy shape to keep it from filling up with gunk. The snipping was probably not useful.

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5. Fasten it in, or near, a tree where beetles like to hang out. Don't do what I did, and tie it to something--because when you want to dump the stinky, drippy dead beetles it's a pain to have to untie a knot. Now I use a spring-loaded clamp to clip it in place. The final step (best done after it's in place) is to put 2-3 drops of dishwashing detergent in the bottom, and then pour in water till it starts to dribble out the slits in the jug. The detergent water will quickly drown the beetles.
 

That's it. Check it every couple of days, because soapy dead-beetle soup is super stinky, and probably won't attract many new beetles. Unclip it, pull out  the funnel and dump the beetles, hose it out, and reset it. This year it was just an experiment to see if it works. It does. Now I'll start saving milk jugs & soda bottles to have a bunch of traps ready for next year.


Excellent idea and presentation! Thank you so much. Last year I had so much trouble with these fig beetles.

Thank you for taking the time to post this!

Fannnnnnnnnnnnnnnn-Tastic!

And a bump so more people get to see this  :)

I'm glad some found it useful--there's another (smaller) bunch in the trap today. Maybe it's time to change the attractant. Now if there was only an effective way to eliminate large quantities of dried fruit beetles (Carpophilus spp), I'd be in business!

I'm on this project now! They are swarming around here! Thanks for tip!

You're welcome. Unfortunately, even with three traps going constantly and frequent forays into the fig forest to catch them in a big jar, killing thousands per day, it hasn't made much of a dent in the beetle population this year. They're everywhere, and have destroyed most of the figs. rdc 2017-07-30 beetles_6618.jpg 

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That's too bad. Awesome photo's though. I almost missed the flying beetle.

I have them like the plague again this year too. They used to just eat bird pecked soured figs but since I'm keeping the birds away they now attack ripe figs. Even eating them thru my organza bags in some way that's hard to figure and unappetizing to think about.

I tried a trap with isopropyl and none showed an interest in that as a bait. Even when I put a few soured figs in a 1 gal pot to attract them very few show up, they seem to like stuff hanging on a tree.

I haven't played tennis in a long time but found a new satisfying use for my old racket. With a good wind up you can send a beetle flying 30 yards :-)


When he was still at home, my son used the racquet technique to good effect, but I'll stick with traps & jars.

I'm puzzled a to why you're not having any luck with an alcohol bait--are you using too much? I find that a short wick of about 3/16" diameter through the same-sized hole in the lid of a pill bottle works great. They like it so much, they'll even eat the rolled-up paper towel wick down to a nub if they have access to it. I put my traps about 5 feet off the ground, right next to a tree where they like to hang out, and I'll often get 2-3 inches of beetles per trap in a day. But--I've also noticed that they're also attracted to their own foul smell, and after a bunch of beetles have wallowed around in their own excrement in the trap for a while, then even more are anxious to get in. You might try catching several in a jar and "priming" your trap with them, to see if that helps to get things going.

Hello Ken,

I used a paper towel soggy wet with only alcohol as the bait. Maybe the grape juice makes a difference. Also tried some spiced rum and they are not drinkers of that either.

On a similar note, I tried apple cider vinegar for a fruit fly trap and zero flies showed up. Yet you can find Youtube videos where people attract flies like crazy with that stuff.

This year, the figeater beetles have been terrible in Waddell, AZ. Thanks for posting directions for making a figeater beetle trap, Ken. It was a new idea to me and made me wonder, "If there are figeater beetle traps, why not traps for the tiny beetles too?" A google search led to information about trapping those little fruit souring beetles that get into our peaches and figs here. Google tells all: http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=15728 This page has a diagram of a fruit souring beetle trap, but does not show step by step directions: http://ipm.ucanr.edu/PMG/FIG/fig-f02.html

Crademan--thanks for the heads-up about trapping dried-fruit beetles. Strangely, I haven't even seen one this year, but if the show up again maybe I'll try a trap targeted specifically at them.

Cjccmc--I wonder if, from the beetles' perspective, your soaked paper towel approach might have been "too much of a good thing?" It could be that a steady, but slight whiff of alcohol would be more effective than a big cloud of it? Hard to say. I've also found that different configurations of traps produce different results in my yard--but they all catch something.

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