Fruit trees are blooming (or just finishing) all over the island, so it’s time to talk about our least favorite creatures – pests! While there are plenty of beneficial insects, including some you may not even realize are helping around the garden, there are a few that will ruin your next apple pie.
Effective pest control methods can eliminate apple maggot and coddling moth within 2-3 years, which means that if you disrupt their life cycle they’ll eventually disappear. It definitely takes some effort, but the benefits to you in terms of better quality fruit and the health of your trees are worth it!
Long term strategies for controlling or eliminating pests include planting to attract beneficial insects; yearly application of nematodes, Kaolin clay or dormant oil; and traps.
What they do: With the abundance of apple trees on South Whidbey, apple maggot might be our most common pest. When the adult flies emerge in late spring the females spend some time feeding & mating before settling down to lay eggs. The female flies pierce the skin of an apple to lay eggs, which take about a week to hatch into larvae. All of the damage is done during the larval stage while they tunnel around, eating away at the developing apple before leaving to pupate. Apple maggot larvae typically leave the fruit once it has fallen to the ground, where they find a cozy spot to settle in for the winter. City Fruit has a great guide here
How to spot them: Watch for the flies buzzing around your trees in the late spring/early summer. Prime time for fly activity is July & August while the fruit is ripening. Divots in the skin of the apple are indicators that an adult fly has laid eggs in the fruit.
How to fend them off: Apple maggots work on visual cues, so the sight of an apple is what leads them on, making red apple traps especially effective. You can buy them locally, or make your own using crumpled red paper inside a sandwich bag. You can find instructions on our website.
Last year the South Whidbey HS Ag students helped us make a batch of apple maggot traps for our tree donors. We still have some left, so if you don’t feel like making your own, stop by Good Cheer and grab a bag!
Clean up all the ground fruit! If there are apple maggots present, you can disrupt their life cycle by picking up and disposing of ground fruit so that the pupae have nowhere to spend the winter. Putting the ground fruit in a compost pile helps, or offer it up to a friend or neighbor who has goats, chickens, or pigs to feed.
Cultivate natural predators like Lacewing flies, which eat harmful insects. Birds will also eat hatching flies, and I’ve heard people swear by chickens in the orchard as a way to get rid of pests.
What they do: Attracted by scent rather than sight, adult coddling moths lay eggs on the leaves of pear or apple trees. When the eggs hatch, the larvae head for the nearest juicy fruit and tunnel in, leaving a hole filled with frass – brownish larvae poop that looks a little like tobacco.
Yuk. Like apple maggot, the larvae leave the fruit once it hits the ground and over winter under a nice piece of bark. Coddling moths emerge in late April/early May, and are active through June & July. Adult moths emerge from their cocoons July-September.
How to spot them: Watch for moths flying around, look for holes filled with frass on the bottoms of apples and pears, and watch for larvae making their way down the tree to pupate.
How to fend them off: Pick up ground fruit, and if you find signs of coddling moth in fruit on the tree, remove it and discard it into the compost pile. Cultivate natural predators, use dormant oil or nematodes (same as apple maggot, which is handy since you can kill two pests with one method). According to this you can wrap cardboard or burlap around the base of the tree and catch larvae that are heading to the ground to pupate.
Wasps & Hornets
Nature’s flying death squad. Maybe just run. Start a new life on another continent. I hear Antarctica is nice this time of year.
Fun story: Once upon a time I was glamping in eastern Washington with my boyfriend. Since we were car camping we brought along plenty of breakfast luxuries, including bacon and ham, like a couple of rookies. Yellowjackets love meat. Especially bacon grease. They’d gather around every morning as we cooked, which made for an interesting (that means terrifying) time. We tried setting a paper towel covered in bacon grease in an empty fire pit to lure them away…no dice. But we did find out that if we took our plates about 20 feet away to eat they wouldn’t follow us. They stayed around the camp stove to fuss with the frying pan. It made clean up awkward, but we got to eat without getting an accidental bite of waspy pancakes.
So wasps are awful. Anyone with a barn or wooden structure knows how quickly they can build nests and take over. They munch on soft-skinned fruit, and will sting the heck out of you for no good reason. But, they’re also predatory insects and will carry off caterpillars and leaf beetle larvae, so they’re not all bad.
You can buy wasp traps locally, or hang jars of sugar water for them to drown in. Because while they may have some redeeming qualities, they’re mostly the evil minions of some demented forest villain.
Common not just to veggies, but also to fruit trees and other garden plants. The one benefit of aphids is that they attract ladybugs.
A simple way to get rid of them – soapy water. Use biodegradable dish soap mixed with water in a squirt bottle and spray vigorously. I’ve used this in my own garden for years and it doesn’t seem to bother the plants at all. Biodegradable soaps (7th Generation, Myers, Dr. Bronner’s, etc) break down and don’t contaminate water sources. (Did you know that you can get biodegradable dish soap in bulk at the Make Whidbey store? Check it out – it’s cheaper than store bought and it works beautifully!)
Bees, lacewings, lady bugs, and spiders are all helpful insects to have around. You can plant things they like to keep them hanging around your garden. Some of the best plants for attracting beneficial insects are also garden favorites: Fern-leaf Yarrow, Dill, Mallow, Coriander, Queen Anne’s Lace, Butterfly Weed, Penstemon, Marigold, Lobelia, and Lemon Balm. Check out a longer list here
Stay tuned for next month – we’ll talk about fruit tree diseases, growing a row for the food bank, and feeding your fruit trees.