Downloaded from https://academic.oup.com/amt/article-abstract/22/1/1/4639700 by DeepDyve user on 21 July 2020 A: POME FRUITS Arthropod Management Tests, Vol. 22 1 POME FRUITS APPLE Malus domestica Borkhauser 'Delicious' E. H. Beers (1A) European red mite (ERM); Panonychus ulmi (Koch) Tree Fruit Research and Extension Center Twospotted spider mite (TSM); Tetranychus urticae Koch 1100 N. Western Avenue Western predatory mite (WPM); Typhlodromus occidentalis Nesbitt Wenatchee, W A 98801 (509)663-8181 ext. 234 EFFECT OF EXPERIMENTAL AND REGISTERED MITICIDES ON TWOSPOTTED SPIDER MITE AND EUROPEAN RED MITE, 1996: This experiment was conducted in a commercial orchard of mature 'Delicious' apples at Arrowhead Ranch, Bridgeport, WA. The plot was laid out in 2 rows, with buffer trees between treated trees in the row, and a buffer row between rows containing treatments. A pre-treatment count was made and replicates were assigned to blocks according to initial population and treatments were randomly assigned within replicates. The experimental design was a randomized complete block with 4 replicates. Treatments were applied 5 Jul 1996 with a handgun sprayer operated at about 300 psi. Twenty randomly selected leaves were collected from each replicate tree, and mites were removed from the leaves with a leaf-brushing machine. Mites were counted with the aid of a binocular microscope. A pretreatment sample and weekly post-treatment samples were taken. Pre-treatment populations of phytophagous mites were low, and consisted of a mixed population of TSM and ERM. All treatments except Vendex suppressed mite populations relative to the check by 4 DAT. Although populations were much reduced by this treatment by 12 DAT, they were not sig nificantly different from the check. By 30 Jul, mite populations crashed in the check, and no differences among treatments were found thereafter. Popula tions of the predatory mite, T. occidentalis, were moderate at the beginning of the test, but peaked in the check on 23 Jul and suppressed the tetranychid mite populations in the corresponding untreated check. The survival of predators was excellent in the Vendex treatment. The Oracle and Agri-Mek sup pressed predatory mites 12 DA T in relation to the check, and populations were generally lower than in the check throughout the post-application period. The high rate of Oracle appeared to cause the greatest reduction in predator population; the low rate of Oracle and Agri-Mek left a substantial residual pop ulation. Rate 17 Jul 23 Jul" 7 Aug 13 Aug 20 Aug" Treatment form/acre 3 Jul 9 Jul" 30 Jul 0.05a 0.01a 0.00a Oracle 60WP 0.417 1b 1.69a 0.48b 1.05a 0.96a 0.26a Oracle 60WP 0.833 lb 1.94a 0.76a 0.33a 0.30a 0.14a 0.00a 0.05a 0.56b 0.06a 0.01a 0.01a Agri-Mek 0.15EC lOflo z 1.60a 0.21b 0.28a 0.13a 0.28a +0.25 % oil 0.00a 0.00a Vendex 50W 2.01b 2.01a 1.5 la b 0.19a 0.75a 0.01a 0.00a 1.48a 1.15a 0.20a 0.06a 0.05a 0.00a Untreated check 1.70a 4.13a Means in a column followed by the same letter are not significantly different, Waller-Duncan fc-ratio ?-test,£-ratio = 100. "Data transformed log(y+1) due to nonhomogeneity of variances (Levene's test). Rate Treatment 3 Jul 9 Jul 17 Jul 23 Jul 30 Jul 7 Aug 13 Aug 20 Aug form/acre Oracle 60WP 0.417 lb 0.66a 0.58b 1.24bc 0.39b 0.35a 0.18b 0.35ab 0.05c Oracle 60WP 0.833 lb 0.26a 0.06bc 0.05b 0.19c 0.35b 0.33a 0.20b 0.08b lOflo z 0.31a 0.45b 0.35c 1.10b 0.70a 0.49b 0.44ab Agri-Mek 0.15EC 0.29bc +0.25 % oil Vendex 50W 2.01b 0.99a 1.20ab 1.96ab 0.49b 0.16a 0.44b 0.15ab 1.56a Untreated check 0.56a 2.24a 3.28a 2.53a 0.84a 1.45a 0.46a 0.90ab Means in a column followed by the same letter are not significantly different, Waller-Duncan &-ratio f-test, i-ratio = 100. APPLE Malus domestica Borkhauser 'Delicious' E. H. Beers (2A) European red mite (ERM); Panonychus ulmi (Koch) Tree Fruit Research and Extension Center Twospotted spider mite (TSM); Tetranychus urticae Koch 1100 N. Western Avenue Western predatory mite (WPM); Typhlodromus occidentalis Nesbitt Wenatchee, W A 98801 (509)663-8181 ext. 234 EFFECT OF ACARICIDES ON PREDATORY MITES, 1996: This experiment was conducted in a mature 'Fuji' orchard in Pateros, WA , with undertree spinner-type sprinklers. A pre-treatment count was used to randomize the treatments among trees with similar mite populations. Three single tree replicates per treatment were used. The treated trees had buffer trees separating them in the rows, and buffer rows separated rows containing treated trees. Treatments were applied with a handgun sprayer to the point of drip on 28 Aug, 1996. Mites were sampled by collecting 20 leaves/replicate, and were kept cool until counting. Mites were removed from the leaves with a leaf-brushing machine, and counted on the sticky surface of the glass plate with the aid of a stereoscopic microscope. The primary predatory species was WPM. All treatments left significant populations of predators, which was not significantly different from the un treated check. This indicates that all materials tested may be compatible with integrated mite control. The post-treatment population of TSM in the check was so low that it was not possible to draw any conclusions about the materials' acaricidal activity.
Arthropod Management Tests – Oxford University Press
Published: Jan 1, 1997