The impact of woolly apple aphids (WAA), Eriosoma lanigerum (Hausmann), on growth and nutrient content of plant tissues was investigated with young apple trees grown in growth chambers. One hundred forty-four individually potted and caged tissue cultured 'M.7' apple trees were divided equally into two treatments (infested with five first-instr WAA on the shoot or infested with five first-instar WAA on the roots) and an uninfested control. Root galls and stem splits began forming as a result of WAA feeding after only 4 and 8 wk, respectively. Four weeks after infestation, trees in the WAA-infested treatments had significantly greater shoot and root dry weight than the control trees. After 16 wk, the growth rate of infested trees had decreased and the dry weights of roots, shoots, and leaves were greater in control trees than in treated trees. The difference in dry weight increased at 21 wk. In general, roots were more severely affected by WAA; populations of WAA on roots caused a greater reduction in tissue weights than WAA feeding on the shoot. WAA feeding also caused a decrease in foliar nitrogen and phosphorus; results from the other elemental analyses were variable. Results from the elemental analysis of root tissue indicated that WAA disrupted the nutrient balance of these apple trees.
Document Type: Research Article
Publication date: August 1, 1988
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Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.