We observed that most of the gypsy moths that entered the purchased gypsy moth traps eventually came back out. Yes, some did not, and after a few days the trap would have a wad of dead gypsy moths in the bottom. This would make you think that the trap worked. Well it did, sort of, but the fact is that many, and maybe most, escaped.
The homemade traps we built corrected three problems that we observed with the purchased traps.
Three major problems with purchased traps:
1. After entering the trap through one of the holes, the moths would fly around inside the trap looking for a way back out. Some did. Others would eventually tire and drop to the bottom. There they would rest, then begin flying again and maybe find a way out, and escape. Our solution to this problem was to add a couple of inches of water in the bottom of the jar or bottle, with a dash of dish detergent added. The detergent breaks the surface tension, and assures that when a moth hits the water at the bottom, he sinks and drowns almost instantly. Then when a moth tires and falls to the bottom, he is a goner; no second chance.
2. As the walls of the purchased traps were green in color, it was easy for the moths to see the way out through the clear holes. The escape route was being illuminated. They headed for daylight, as the clear hole contrasted with the dark matt-green jar sides. Instead, we chose jars or bottles with clear sides. Then the clear holes did not stand out against the clear sides. This made it harder for the moths to see a way out.
3. We found that bottles or jars with a bulging top section and a narrower body worked best. We cut the entrance holes just below where the bulge started. After entering, the moths tended to fly up into the bulging part of the jar, where there were no holes to escape and where the pheremones were taped to the inside of the lids. The purchased traps had straight sides allowing the moths to flutter up and down looking for an exit.
Did we say that the homemade traps were cheaper? Used Vitamin Water bottles were perfect. Many other clear juice and water bottles make excellent male moth traps. If you are using store-bought traps, you can minimize exiting by using different bags than those that come in the kit. We found that replacing the short stiff bags with longer softer ones (i.e. the bags that come on your newspapers) didn't allow the moths to fly back up and out as easily. It might be interesting to note that the bought traps we emptied once a week. Whereas, the home-made and modified traps we had to empty once a day.
1. Select a clear plastic jar or bottle. Those with bulging top sections larger than the sides are best.
2. Cut about 4 holes in the shape of slots around the jar or bottle, just below where the bulge starts. The holes should be one and a quarter inches long, and three eights of an inch high. (More or less - don't drive yourself crazy with measurements) Toenail/fingernail scissors work well. You can punch a hole with the pointy ends and make a rounded slit with the blades.
3. Take off the lid and punch a hole in the center. String a piece of twine through the hole with a knot at the inside end. We put a screw-eye in the top of the lid and attached the twine onto that. It kept the string from getting wet and disgusting, and let us empty the bottles easier.
4. Tape a strip of pheromone bait to the inside or the jar or bottle lid so that it isn't all covered with tape, but hangs from the lid down into the bottle. (Hint: If you touch the pheremone, or the plastic sleeve it comes in, be sure to wash your hands, or the males will flutter right into you looking for the female they think you are holding. I make mine while wearing disposable gloves.)
5. Make a loop in the outside of the twine; rig a way to hang the bottle from a tree limb or wherever you want it.
6. Put a couple of inches of water, with a dash of Dawn or some other dish detergent into the bottom of the jar or bottle. (Hint: put the water in first or you will have bubbles in the bottom)
7. Hang it up somewhere and stand back! (Hint: Don't hang it near a doorway, or you will have to wear a mask to go outside, and some will get into your house.)
That's it! You are ready to catch some moths. Note that only the male gypsy moths fly. Female moths don't fly, they flutter and climb and wait for the males to find them.