Orchard Management
The battle goes on, with a variety of strategies, but there are new arrivals every couple of years.
P
rior to the integrated mite control program initiated by Jack Arrand, the provincial entomologist in the mid-1960s, whole blocks of apples would appear brown. I distinctly remember festoons of McDaniel mite hanging like drapes from big old apple trees. Pears went through the same progression; we used one Pear Psylla control material after another and at the same time got hit with terrible populations of Rust Mite, as well as Red and McDaniel mites. Linda Edwards was one of the experts who led us out of that mess and into a much better situation with a number of predators to control Pear Psylla.
I also remember as a summer student in the mid-60s making up a mixture of molasses and brown sugar to put in apple juice cans to attract codling moth. It was my job to clean out the traps and separate the good guys from the bad guys and come up with a count.
We progressed to traps with live females to attract the males and finally to the use of winged pheromone traps and degree day models. It took a number of years, but growers gradually took on the newer technology and we arrived at a pretty good place with fewer sprays of less toxic materials. For a number of years now we have used more degree day models, appropriate traps for different pests etc., and a relatively soft or mild spray program overall.
We now have new pests that are arriving on average of one every two years. The two more recent and
24 Clear Winged Moth larvae tunneling.
larvae. This registration is a year-by- year thing.
Rimon, an organic material, is registered on apple but not for this pest and focuses on egg and larvae control. It is being used in trials as a trunk spray in spring and fall. It is particularly harsh on predators and if misused during the summer it will initiate fierce mite problems (There is no desire to upset the integrated program that has been a great success story).
British Columbia FRUIT GROWER • Spring 2011
By Peter Waterman The insect pest blitz
threatening pests are the Clear Winged Moth and the Spotted Winged
Drospohlia.
As in Europe, clear winged moth attacks our clonal apple rootstocks
primarily M9 and Ottawa 3 around burrs and cankers at the at the union and up and down the trunk as high up as branch crotches and into spur systems and pruning cuts and wooly apple aphid wounds. Tunneling under the bark extends 20 to 25 mm. This sort of tunneling makes trees prone to moisture stress. This is exacerbated with excessive crop loads and coarse soils with poor water holding capacity.
As the production guide states, there are no registered control materials, although Spinosad has been used as a summer trunk spray on emergency registration. This use calls for two or three sprays targeting the hatching
Clear Winged Moth.
As I stated, pruning to eliminate excessive crop load will assist but other cultural efforts do have some success. Minimizing wounds to trees, removing young trees with cankers and sealing wounds are helpful. Wrapping trunks with polyester batting will discourage egg laying and prevent escape of emerging adults. Mass trapping with grape juice in a two-litre plastic bottle attracts both females and males. Mating disruption is being examined by Pacific Agri-food Research Centre scientists. Biological control is also being pursued. Research and packing house field staff are making what looks like successful moves that are in line with our history of maximizing natural predators and technological advances that will minimize the economic threat of this pest.
Spotted Winged Drosophila may prove to be very difficult. It was first detected in the fall of 2009 and a monitoring project was undertaken in 2010. Monitoring started in early May and continued much later than first anticipated and high catches continued until mid-November. Numbers increase in late August and there was a dramatic increase in October. SWD is particularly serious in that the female attacks undamaged fruit with its sawlike ovipositor. As crops ripened it became apparent that the fruit was more attractive than the apple vinegar traps. SWD attacks a full range of berries and soft fruits — cherries, peaches, nectarines, apricots, plums, blackberries, raspberries, blueberries and grapes, as well as a range of wild hosts, from snowberry to Oregon grape, Saskatoon, mountain
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