Today in the orchard
(Report by Skylar.) It’s time to spray for Fall Webworm (Hyphantria cunea). Their characteristic webs that engulf little sections of various tree species are hard to miss. In addition to stripping the branch clean of leaves, growing, and pooping, the caterpillars perform a dance, which they carry out in perfect unison. Flick! Each and every caterpillar bends their body in one direction, pauses for a second, and then —Flick!— again in the opposite direction. It’s amazing to observe, but I couldn’t tell you why they do it. We use DiPel to kill them. DiPel is a biological insecticide, containing spores of the bacterium Bacillus thuringiensis subsp. kurstaki (BT). It is effective against Lepidoptera, the order of insects that includes moths and butterflies. When a caterpillar eats a leaf sprayed with BT, the bacteria destroy the digestive tract of the caterpillar and kill it. Most other insects and larger animals have enough acid in their stomachs to prevent the growth of B. thuringiensis in their digestive tract; thus DiPel is considered safe for people, pollinators, and many other animals that you are not aiming to kill. In addition to the Dipel, we added tansy tea and a quart of each Regalia and Calplus to the sprayer tank. Ideally every tree should get a dose of spray, but our goal was to stretch the tank to the whole orchard. We went lighter on the trees with few fruit, and heavier on those with more fruit. It was really just luck, but we reached the end of the orchard and the end of the tank at almost exactly the same time. Perfect!
Andy and Polly and old seedling apples, Isle Au Haut, 2019
Later Polly Giragosian and Andy Brennan, the wizards behind Aaron Burr Cider, stopped by for a visit. We chatted about sulfites in cider and painting trees with manure and clay. Then it was time to fill the tank with another round of spray and make our way through the BRC, down the driveway, around the houses, and to the old orchards to spray the rest of the apples, pears and plums.
