The winter moth (Operophtera brumata) will leave its calling
card on your apple tree in the form of numerous holes in the
leaves - it weakens the tree and leaves it open to other diseases.
The caterpillar stage of the winter moth feeds on the leaves,
blossoms and young fruitlets during the spring. The caterpillar
weaves a silken thread loosely through the leaves and the small
holes made at this stage often go unnoticed. As the leaves
develop, the holes enlarge and become noticeable, but the
caterpillar has done it's dastardly work by that stage and has
gone back down the tree into the soil to pupate into the fully
grown winter moth - they will emerge from the soil anytime
between November and March.
life cycle is continued because of a very unusual characteristic
of the winter moth - only the male moth's can fly; the female's
wings are totally useless for flying. The females climb all the
way up the tree trunk into the main tree to lay their eggs
How to Treat Winter Moth
Preventative treatment is the only reliable way of controlling
this pest. Tie a sticky grease band (available at most garden
centres) around the trunk during the period when the females
might be making their way back up the trunk - October to
April should do the job. One tip - if the tree has a supporting
stake, tie a band around that as well! Keep the band clean of
leaves and other debris. Remove and burn it in April.