Apple trees (Malus X domestica Borkhauser) of 'Bisbee Delicious' (a spur type), 'Triple Red Delicious' (a nonspur type), 'Golden Delicious', and 'Red Stayman 201' were subjected to various levels of European red mite, Panonychus ulmi (Koch), injury for 3 yr after planting. Mite injury (as measured by the mean seasonal cumulative mite days for the 3 seasons) ranged from 35 to 1,821 for the experimental trees. Dry matter accumulation in tree partitions was measured at the end of the 3rd growing season, and the effect of mite injury was analyzed. All 4 cultivars tested responded to mite injury in a similar manner, although tree size was influenced greatly by intrinsic differences among cultivars. Reductions in dry matter accumulation in the tree as a whole, the aerial portions, and the root systems occurred as a result of mite injury. The percentage of reduction per 1,000 mite days was greatest for the root system (7-12%), whereas reductions in other partitions averaged about 6%. The effect of mite injury during the non bearing phase, although statistically significant, is not a likely critical factor in the establishment and early production of an orchard. The importance of establishing biological mite control with Stethorus punctum (LeConte) early in the life of an orchard outweighs any negative effects on early growth.
Document Type: Research Article
Publication date: August 1, 1995
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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.