the Walnut Diary

In The Review Mirror this week I ran onto a mention of the Wesport Lions’ giveaway of rubber bands impregnated with gypsy moth pheromones at their recycling depot on Salem Road, beginning today. They opened up at the shop at 10:00 a.m. Parking was an issue, and the line-up had the air but none of the solemnity of a vaccination program. A guy named Maynard (not a cousin of mine, it turns out) explained that a Waterloo professor discovered a way to make an ordinary rubber band utterly irresistible to a male gypsy moth. A hand-out showed a variety of extremely low-tech traps, all of which were well filled with dead brown moths.

Please consider the device in the photo below my contribution to the growing literature on the subject. The original paint in the tray was a shade of green for my grand-daughter’s bed entitled “Lazy Caterpillar.” She suggests that this decorator touch may have enhanced the trap’s effectiveness.

To build the trap I tried an old paint tray with a twig and an elastic band tangled on it over a pool of diluted doggie shampoo. Within the hour it had drowned a dozen moths. The tray sits on a shelf in an open shed next to my UTV. It is out of the weather, but readily available to the moths. I believe that the infestation of the adjacent tree stemmed from a series of egg sacs along the ridgepole of this outbuilding.

As of press time there were sixteen casualties in the pan, with no evidence of other swains in the offing. On a hunch I turned off one outdoor security light for tonight and left the overhead light in the shed on to attract moths. The local cohort may be a little late to mature, so I shall remain vigilant.

UPDATE: 9 July, 2021. 7:30 a.m. Four more moths entered the trap overnight, including one brown specimen which may be of another species. The thorax is fatter than the others. All four bodies are larger than the earlier crop. There are no other moths which I could see in the area this morning.

UPDATE: 9 July, evening. When I turned on the light in the Kioti house this evening, I noticed the rafters of the shed. They were loaded with pupating gypsy moths. I had at them with half a tank of water from the Koti’s pump, but then I started scraping the insect clusters down with the back of a garden rake. It became rather mushy underfoot on the gravel floor of the shed.

UPDATE: 10 July, 2021, 9:37 p.m. In early afternoon my sister called to report that, despite the success of the moth traps, she discovered huge gobs of pupating moths in the red ornamental maple at her house. I Googled an idea and the screen which came up suggested that yes, a pressure washer works well for blasting moth pupae off trees, though you still must track them down and step on them to be effective.

A tank of gas and a litre of dish soap, along with a lot of water, made an appreciable improvement on the appearance of the tree. We’ll see better in daylight.

UPDATE: 13 July, 2021. The hatch is now on and abundant male moths are filling the trap to where they are walking on the bodies to get to the elastic lure. I dump and replenish the trap twice a day. There is no question that the trap works, though it may have the effectiveness of a child’s plastic shovel in a blizzard. The pressure washer works quite well at my sister’s house to clean up trees. My red maple is taller than hers and not nearly as encrusted with pupae because of the convenience of the shed roof where I had at them with a rake.

Of personal importance, the caterpillar attacks upon my little apple trees and the row of ten young cherry, red oak and basswood trees along the edge of our front lawn have ceased. The twenty Saskatoon berry bushes are finished bearing for the year and I haven’t seen a caterpillar on one in a week. For low vegetation if you have the time, the best approach is to locate and squish individual raiders.