European Apple Sawfly Update

Growing apples is a complex enterprise with 39 different insects and diseases to contend with in order to produce a quality apple. Fortunately not all have to be dealt with at once. Some are cultivar specific such as blister spot on Crispin and some geographical in nature such as European apple sawfly, (EAS). So what's happening with European apple sawfly? This pest as its name implies comes from Europe, arrived in Long Island, New York in the late 1940's and has been moving slowly westward. Damage from EAS in Ontario has been concentrated mainly in the apple-growing area east of Brockville and the Ottawa Valley. In 1998, European apple sawfly was documented in the Kingston area and by 2008 European apple sawfly has spread westward and become established as far west as Port Hope.

A pre or post bloom insecticide is needed to manage this pest and azinphosmethyl (Guthion or Sniper) is the only registered product. With the phase out of this chemistry, IPM strategies for EAS are being developed in two ways. For the last 3 years new reduced risk insecticides are being tested to manage this pest with good results. Also researchers from Agriculture and Agri-Food Canada have initiated a classical biological program. The species specific larval parasite Lathrolestes ensator (Brauns) has been introduced to Quebec and Eastern Ontario orchards. Once this parasite is established at these sites, these sites will be used as seed orchards to disseminate the larval parasite to sawfly infested orchards. This is not a stand alone method of control but can be used in conjunction with reduced risk pesticides and cultural methods to reduce the population of European apple sawfly.

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