How to Manage Pests
UC Pest Management Guidelines
Scientific Name: Cydia pomonella
(Reviewed 6/06, updated 4/09)
In this Guideline:
DESCRIPTION OF THE PEST
Larvae are white to pinkish caterpillars with brown to black heads. Adult moths have gray wings with a copper spot on each wing tip. Mature larvae overwinter in silken cells under loose bark on the tree, and moths emerge from March to May. Adults mate and lay eggs; larvae feed on small fruit. A second generation appears in June and often a third one in August, depending on temperatures.
Fruit feeding by codling moth is generally not a problem but can damage fruit in some orchards. Codling moth larvae usually tunnel all the way to the pits of fruit; extrusions of frass or excrement are often found at the entrance of the larval tunnels.
Occasionally codling moth is a pest in prunes in a few locations in the Sacramento Valley. A single treatment timed using pheromone traps and degree-days should be all that is needed at these sites.
An important egg and larval parasite is the braconid wasp Ascogaster quadridentata.
Remove abandoned or unsprayed apple, pear, plum, apricot, and walnut trees near the prune orchard.
Calculate degree-days for codling moth in your location.
Learn to use degree-days to time insecticide applications.
Monitoring and Treatment Decisions Sunset temperatures
Pheromone traps, degree-days (DD), and twilight temperatures are used to monitor codling moth activity. Place traps in the orchard soon after bud break and monitor twice a week to determine first moth emergence. For more information see PHEROMONE TRAPS and record results on a monitoring form . The biofix is the first date that moths are consistently found in traps and sunset temperatures have reached 62°F. To predict egg hatch, begin accumulating degree-days from the biofix, using a lower threshold of 50°F and an upper threshold of 88°F. Generation time for the first generation of codling moth is 1060 DD, whereas generation time for summer flights averages about 160 DD more.
First generation egg hatch
If a treatment is necessary, time the first spray to the beginning of egg hatch to kill emerging larvae 300 DD after the first biofix for moderate to heavy populations, and 400 to 500 DD for light populations.
Second generation egg hatch
Use pheromone trap catches to detect an increase in flight activity around 1060 DD from the first biofix, which signals the start of the next moth flight. If a second application is necessary, apply it when 250 DD have accumulated from the second biofix.
Fruit damage sample
In mid-July, take a fruit damage sample to assess the overall effectiveness of the current year's IPM program and to determine next year's needs. For more information, see FRUIT EVALUATION AT HARVEST. Record on a monitoring form the number of fruit infested by larvae, type of larvae present, whether the damage is surface feeding only or if the larvae penetrated the fruit.
UC IPM Pest Management Guidelines:
Insects and Mites
Acknowledgment for contributions to Insects and Mites:
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