The wet spring and warm winter have resulted in a lot more pests attacking gardens across Maine, James Dill, a pest management specialist with the University of Maine Cooperative Extension in Orono, said last week.
Some of the pests are ones we deal with every year — slugs, ticks, aphids, cutworms and the like — while others are pests new to Maine that could cause major problems for home gardeners and commercial farmers.
Over the winter, state officials warned growers about four pests. Now that the growing season has started, some of them have been found in the state, but for others the watch continues.
“The brown marmorated stink bug is still knocking at our door,” Dill said. “I’m sure it is in the state somewhere, but we have not seen a problem with it yet. I expect it will cause some problem in the next few years because it will attack apples.”
The brown marmorated stink bug has an alternating black-and-white edging on its shield-shaped back and alternating black and white antennae.
The European crane fly attacks turf and has been found along the coast in places such as Mount Desert Island, but it has not been a big problem in other parts of the state.
The spotted wing drosophila was found last fall in parts of Maine, and the state is monitoring it closely to see where it shows up this summer.
“We probably have at least 100 places where we have traps set up — in crops such as strawberries, high-bush blueberries and greenhouse tomatoes,” Dill said. “We will set up 100 or 200 more for the low-bush blueberries.”
The drosophila is a fruit fly, but unlike most fruit flies, it will eat fruit that is ripening, not just fruit that is past its prime.
Dill said the threshold for treating the spotted wing drosophila is one, which means that if the pest is seen in an area with low-bush blueberries, the fields will have to be sprayed weekly for for five to six weeks — which will be a huge expense for the blueberry growers, who now do not have to spray for the most part.
Dill said the drosophila starts out slowly, so it is not surprising it has not been seen this early in the season.
But it tends to pick up as the summer progresses, so people who grow such crops as fall raspberries will be hit especially hard.
“Those are mostly pick-your-own operations, and since you can’t let people in right after you’ve sprayed, some growers are saying they will just get out of the business if this comes,” Dill said.
Dill also said that homeowners who grow cherries are going to be affected by the drosophila, because they love cherries.
Winter moth is another pest that is going to affect blueberries and cranberries.
The pest has been in Massachusetts for several years, but has just started coming into Maine, Dill said.
The moth gets its name because it flies throughout the cold months, coming to houses in swarms. But it is the caterpillar form that is out now and is going to be attacking the fruit.
The browntail moth is expanding its range in Maine.
It normally has been a coastal pest, mostly in Casco Bay, but has shown up in spots as much as 60 miles inland, Dill said.
With all of the rain in June, slugs have been a problem and, somewhat surprisingly, so have snails, Dill said.
“There have been a lot of calls about snails climbing up ornamentals and leaving slime trails and on lupines, as well as grass-type crops,” he said.
Most commercial slug killers use iron phosphate, and the manufacturers recommend that people use it around their vegetable gardens — not in them — so Dill wonders how safe they are.
But he says beer does work if you have the lip of the can or pie plate level with the ground. And you can put a row of coarse sand around the garden plants you want to save, because the slugs get bogged down by the weight of the sand sticking to them.
It also has been a bad year for cutworms in vegetable gardens and wire worms, especially where people created new gardens in areas that had been covered by sod.
The gypsy moth comes and goes, and this is looking like a year that will have an outbreak of that pest.
“We have had quite a few hydrangea leaf tiers,” Dill said. “This is not a serious pest, but it is kind of unusual. It ties the leaves up and gets inside of them and just feeds.”
Dill urges people to let the state know if they have seen any of the new pests, and to send the state an example of any insect that they don’t recognize.
The process is described at the University of Maine Cooperative Extension’s home and garden website, http://umaine.edu/home-and- garden-ipm, or people can contact their county extension office for directions on how to send something to the state’s diagnostic lab.
TWELVE GARDENS will be open to visitors from 9 a.m. to 3 p.m. Saturday during the Saco Celebrates with Gardens tour, part of the city’s 250th anniversary celebration.
Tickets cost $12 and are available at Saco’s Dyer Library, The Blue Elephant Cafe, Biddeford’s McArthur Library, Nonesuch Books at Biddeford Crossing and, on the day of the show, at the Saco train station.
Tom Atwell has been writing the Maine Gardener column since 2004. He is a freelance writer gardening in Cape Elizabeth and can be contacted at 767-2297 or at: [email protected]