How to Monitor a Codling Moth Trap (and What to Do When You Catch One)

Codling moth is one of the most common pests affecting apple, pear, and crabapple trees in the Pacific Northwest. The adult moth lays eggs on developing fruit, and the larvae tunnel inside—causing the familiar “wormy apple” problem.

To manage codling moth responsibly, we use monitoring traps as part of an Integrated Pest Management (IPM) approach. These traps help us determine if and when treatment is needed, rather than spraying on a fixed schedule.This guide explains how your codling moth trap works, how to check it, and when to contact us.

What Does the Trap Look Like?

A single white trap made of waxed cardboard

• Hung in the tree canopy

• Contains a sticky insert and a pheromone lure

• The lure releases a scent that attracts male codling moths only.

The trap does not catch females and does not stop the infestation by itself — it is strictly a monitoring tool.

When Will the Trap Be Active?

Codling moth flight activity typically peaks: April through June in coastal BC

This timing varies slightly each year depending on spring temperatures. The trap allows us to track when moths are present and in what numbers.

How Often Should I Check the Trap?

• We recommend checking the trap: 2–3 times per week

• Look at the sticky insert and count the number of codling moths present.

• Other insects may get caught, but only codling moths are relevant for treatment decisions.

What Does a Codling Moth Look Like?

Use these features to identify them:

• Size: Small moth; wingspan 1.3–1.9 cm

• Color: Mottled gray-brown with coppery or gold-rimmed markings

• Hindwings: Pale brown

• Resting shape: Wings held in a tent-like position

• Antennae: Thin and slightly curved at the tips

If you’re unsure, you can take a photo and email it to us.

Adult codling moth (Photo credit:  Steve Schoof, NC State) 

When Should I Contact Arbutus?

Please contact us as soon as you observe five (5) codling moths in the trap.

📧 Email: hello@arbutustree.ca
📞 Phone: 778-846-3752

This threshold indicates that moth activity is high enough to justify treatment planning. Acting at the right moment is critical — codling moth control is timing-dependent, not just product-dependent.

Why Monitoring Matters

Monitoring allows us to:

• Avoid unnecessary spraying

• Time treatments to match moth life cycles

• Use lower-impact products more effectively

• Reduce harm to beneficial insects

• Save you money by treating only when needed

This is a core principle of Integrated Pest Management (IPM):
observe → decide → act only when justified