University of Vermont Extension
Department of Plant and Soil Science
Dr. Leonard Perry, Extension
University of Vermont
Codling moth, plum curculio,
borers are common pests on tree fruits in New
England. Being ready for these if
you have crabapples,
flowering cherries, and fruit trees, and knowing cultural controls,
you have better fruit with the least harm to the environment. A New England
website of Extension services (pronewengland.org) provides some photos,
information, and further resources on these and other garden problems.
larvae (small caterpillar
stage) hatch in June and early July.
They seek newly developing fruit which they tunnel into, usually
in the center of the fruit and on the developing seeds.
Look for piles of “sawdust” in July on the
flower end of fruit. They feed on apples
and pears, and even the related landscape plants quince, hawthorn, and
crabapple. Affected fruits, if just with
a bite on the surface, usually merely have a surface blemish. Fruits in which larvae have tunneled inside
If using pesticides to
moth, follow label directions, especially in regard to proper timing of
sprays. Biorational pesticides—those
with a biological base—although better for the environment may be less
effective. These include bacteria,
insect growth regulators, viruses, and botanical based products. More on controls and timing can be found in a
Cornell University leaflet
curculio weevils lay eggs in spring on
apple, pear, peach, plum, and cherry fruits once they are pea size. The eggs hatch into larvae which feed on
fruit, causing them to drop. Larvae feed
on seeds of pome fruits (such as apples) but not of stone fruits (such
cherries). If fruits remain, they show D-shaped scars or deformities. If spraying for other pests in the spring,
this one usually will be controlled as well.
Especially watch for this pest in spring on trees near hedgerows
woods where this pest may be present.
There are several species of trunk
borers that kill fruit trees. Adult
beetles lay eggs on lower parts of tree trunks in summer.
The larvae that hatch tunnel throughout the
trunk, causing structural damage and a site for wood rot diseases to
enter. Especially susceptible are young,
unsprayed trees, and those with close-fitting tree guards.
Such guards, put on to deter mammal feeding,
provide an ideal site for these borers to lay their eggs.
Removing these guards in spring helps to
lessen this pest. This insect, too, is usually controlled by sprays for
orchard pests so is most often found on wild or unsprayed trees.
One of the best controls for this
pest is to keep trees healthy. If
planting new ones, or near landscapes, keep them at least 300 yards
other host plants for this pest. These
include crabapples, hawthorns, and shadbush.
Keeping brush and grass mowed and away from trunks allows
predators such as woodpeckers and parasitic wasps to find these pests.
Other potentially serious pests of
tree fruits include various mites, aphids, and San Jose scale. More on all these pests, and controls, can be
found at the above Cornell factsheet website.
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