Codling Moths

Latin Name:

Months of Activity:

Appearance

• Codling moths are ½- to ¾-inch long with gray wings that blend in with most tree bark. The larvae are white to light pink with dark brown heads.

Lifecycle

Moths are active a few hours before and after sunset. They mate when the temperature at sunset is above 16°C. Females lay their eggs on developing fruit or nuts. The larvae bore in. After developing inside the fruit or nut, they leave and drop from the trees. They pupate in bark crevices. The adult moths emerge in spring. Depending on the climate, codling moths can have two, three or four generations in a year.

Damage on the outside of fruit appears as a hole filled with frass (reddishbrown crumbly droppings). Walnuts damaged early in the season are small and will drop off trees.

Pest Control

It's much easier to keep codling moth populations low from the beginning than to suppress a well-established population. Here are some strategies that can help:

• Check fruit every week or two for signs of damage. Remove and destroy any infested fruit with frassfilled holes. Removing fruit before the worms crawl out and begin the next generation is critical to control.
• Keep areas around fruit trees clean. Don’t let dropped fruit sit on the ground. It may be infested.
• Use traps to lure moths. Traps should be put up in mid-March. Use one to two traps in a small tree and two to four traps in a large tree. Hang as high as possible in the tree canopy.
• Bag fruit. Paper lunch bags with the top folded over and slit in the bottom can be placed over developing fruit. Bagging should be done four to six weeks after bloom when the fruit is ½ to 1 inch in diameter.
• Spray with insecticide. Carbaryl (Sevin) is effective on the codling moth, but is harmful to honey bees and has been linked with water quality problems. Organic options are nematodes and granulosis virus. Timing of spraying is important. Trees should be sprayed just before or just as eggs are hatching. One way to time spraying is to spray after finding the first "sting" (worm hole) in fruit. That often happens about a month after the tree blooms.
• Repeat spraying to get other codling moth generations later in the season.

Codling Moth Pest Control News

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Management programmes designed to produce apples with zero-pesticide residues can work but are riskier than conventional regimes and whether or not growers adopt a zero-residue strategy ultimately depends on their customers' "willingness to pay a pre... [more]

Apple Moth Populations Spread
Cherry growers are waiting with bated breath to learn whether they will be allowed to use an insecticide to control a "new" pest that can devastate their crops if left to its own devices. It is the light brown apple moth, a native of Australia, now w... [more]

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