Bug Notes Part 1 — Don Ricks

Codling moth worm. Photo: David Smith

  I work with fruit trees in parks and public places and have made some subjective notes and impressions from this past year. The first of these concern the codling moth (CM).

The codling moth is the first pest to attack fruit in the spring.  Basically, the first generation only goes for apples, and the arrival of the first generation can vary dramatically in terms of the time.  Certain varieties of apples in certain very warm microclimates in parts of Seattle might be first attacked in late May.  Other apples, in locations away from the city and at higher elevations, may not meet the first generation until July.  And some unique places, such as certain San Juan islands, Piper Orchard, or very rural and remote areas may not even have codling moth problems.
At places in the city where the CM is numerous and agressive (what we call “high pressure”) the CM may even eat their way through the foot sox.  In places where CM pressure is high, I found reglar foot sox did not work . . and that even kaolin clay on the regular footies didn’t always work.  What seemed to work were the super-strong foot sox –and especially super-strong foot sox with kaolin clay.  That worked — and it worked convincingly most everywhere.
Ziploc plastic bags and the #2 bleached white paper sacks will also work effectively to keep the CM out where CM pressure is high.  I have had success with fuji bags in Eastern Washington, but they haven’t worked for me in Western Washington.  Different climate; different results.
Regular foot sox will work in many situations where either the particular apple variety is resistant or the CM pressure is low.  It pays, then, to know how bad one’s codling moth problem is in order to solve the problem and have the right tools.  Next year I want to experiment less with mating disruptors, which are questionnable in an urban environment, and work instead with trichogramma wasps, as I look for ways to reduce CM pressure.
The second generation of CM comes later in the summer and can be even more intensive.  It will, in some cases, also attack pears.  Pears have such hard skins early in the summer that no protection is needed until July — and in some cases, no protection is needed at all.  In my opinion, pears deserve additional respect with the knowledge that they are completely resiostant to apple maggot fly and to spotted wing drosophilia, as well as being partially resistant to CM.  Pears are a good pest resistant fruit and deserve more recognition.

One Response to Bug Notes Part 1 — Don Ricks

  1. Bob Baines says:

    Good article with accurate useful information.
    Plant more pears! but choose varieties carefully.

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