codling moth larva on apple

Codling moth larva in apple. Credit: Whitney Cranshaw, Colorado State University. Image Number: 5443215, licensed under CC BY 3.0 US


Codling moth (CM), Cydia pomonella (L.), is a major pest of apple, pear, and walnut in North America. In Montana, moths emerge from pupae in spring, mate, and lay eggs. Larvae hatch, burrow into fruit, and feed on the developing seeds. Mature larvae exit fruit, travel down the trunks of trees to spin cocoons and either overwinter or pupate after a few weeks to produce a second generation of moths in late summer.

MSU-WARC Monitoring Updates

WARC has been tracking biofix at the sites listed in the table below. Biofix is defined here as the first sustained moth capture in spring—when two or more male codling moths are caught in a pheromone trap on two consecutive nights. 

Location Biofix 2019 Biofix 2020
Anaconda  no moths caught no moths caught; predicted: 5/30
Big Timber 6/4  no moths caught; predicted: 5/19
Bozeman 6/8  6/1
Columbia Falls no data 5/27
Corvallis 5/15  5/15
Darby 6/3  5/31
Florence no data 5/16
Fromberg 5/15  5/20
Great Falls 5/17  5/17
Helena 5/28  5/30
Lodge Pole   no moths caught no moths caught; predicted: 5/16
Miles City 5/13  5/19
Missoula 5/15  5/16
Polson  no data 5/24
Red Lodge no data no moths caught; predicted: 6/26
Stevensville 5/16  5/16
Whitehall  no data 5/29


Managing Codling Moth in Montana Commercial Orchards

Managing Codling Moth in Montana Home Orchards

Montana codling moth trap-based biofix compared to two fixed biofix models, 2018-2020

Montana surveys of codling moth damage to apple fruit 2019-2020