Codling Moth Prediction Model

Codling Moth Prediction Model


The codling moth larva is a very destructive pest of apple, pear and peach fruit. This is the ‘worm in the apple’. There are 3 generations per year that require management in commercial orchards in Kentucky.

Identification and Biology
The larva is pinkish with a brown head and can reach 3/4 inch. Pupation occurs in spring about the same time as bloom with adults emerging in late April or early May. The adult is about 3/8 inch (10mm), gray, with distinctive bronze areas on the bottom 1/3 of the wing.

Fig 1
Adult codling moths showing coloration at tip of wings, even when captured in a sticky trap. The larva on the right is pinkish in color.


Control of codling moth in commercial orchards relies on regular scouting of the trees and fruit, pheromone trapping, and the use of weather monitoring and degree day models. Traps should be monitored twice a week early in the season and on a weekly basis starting in mid May.

Pheromone Trapping
Pheromone trapping uses chemical lures to attract male moths. A trap consists of plastic top and bottom held together by a wire hanger with the lure placed inside (1C or 1CP trap). Traps are hung in the southeast part of the tree at eye level, usually 1 for each 10 acres (minimum of 2/orchard) in commercial orchards. Traps should be hung pre-bloom with lures replaced monthly.

Degree Day Accumulation
Initial trap catch in the early spring is termed the biofix. The biofix for codling moth is the starting date of the first sustained flight of moths. Generally, this is when the 5th moth has been captured. After the biofix, degree days are calculated daily and compared with the target values in the following table.

Degree day targets for the various
codling moth insecticides
Insecticide DD target for
application
Imidan
250
Danitol
250
Warrior
250
Voliam Flexi
250
Delegate
250
Altacor
250
Belt
250
Assail
150
Esteem
150
Calypso
150
Intrepid
150
Clutch
150
Rimon
100


Throughout the growing season in commercial orchards, trap catches that exceed an average of five moths per trap per week trigger an insecticide application once the number of degree days have been reached for the chosen insecticide.

More information for Codling Moth.

Under Calculating Insect Degree Days for Codling Moth:

Users of the Insect Degree Day models must select your county of interest and a Biofix Date.
Simply fill out the desired parameters then press the "Submit Choices" button.
County:
Biofix Date:





Ag Weather Center, Department of Biosystems & Agricultural Engineering, University of Kentucky