Number Of Live Mites Research Articles

Control of Twospotted Spider Mite in Peanut, 1990

Abstract Selected pesticides were evaluated for control of TSSM in cv. NC-11C virginiatype peanut in Isle of Wight County, Va. Peanuts were planted 5 May using a 36-inch row spacing. Treatments were applied on 30 Jul using a CO2-pressurized backpack sprayer calibrated to deliver 14.5 gal formulation per acre at 50 psi through three, D2-13 disc-core cone spray nozzles per row, 1 over the top and 1 on each side. A randomized complete block experimental design was used with 4 replicates; plots were 4 rows × 40 ft. Treatments were evaluated 3 h before and 2, 4, 8 and 14 DAT by comparing the number of live mites in a 1.5 cm diam area on 2 randomly selected leaflets/plot. Mite counts were made in the field using 10 × magnification lenses.

Spruce Spider Mite Control on Fraser Fir, State College, 1987

Abstract Fraser fir (1-2 m high) growing at a Christmas tree plantation in State College, Pa., were used to evaluate acaricides against spruce spider mites. Treatments were assigned to heavily infested trees at random and consisted of 4 single-tree replicates. Pretreatment counts indicated 182 mites/single-tree sample. Treatments were applied with a KWH backpack mistblower operating at half throttle on setting 3 for 40 s, delivering 910 ml of finished spray/tree. The first application was made to all trees 21 May under cloudy skies, 18°C, and 8-16 km/h breeze. A second spray was applied to some of the trees 2 Jun under partly sunny skies, 27°C, and 0-16 km/h breeze. Treatments were evaluated 1, 2, 4, and 8 wk after the second application by removing four 10-15-cm-long lateral branch tips from each of the 4 replicates/treatment. Samples were transported in coolers or insulated boxes and shipped by overnite carrier. All samples were immediately processed by passing them through a mite brush 6 times to dislodge mites to a rotating glass plate coated with Tween 20. The number of live mites was counted with the aid of a dissecting microscope.

Apple, European Red Mite, Screening for Resistance to Acaricides, 1983

Abstract Susceptibility of 14 populations of ERM to Plictran, Kelthane, and Omite was assayed in the laboratory using a foliage dip test. A field test was conducted in two orchards to determine whether laboratory tests would predict field performance. In laboratory test bouquets of terminals were collected in each orchard within 3 days of the test, placed in 5 gal pails of water and brought back to the laboratory. Foliage from all orchards except Cream Ridge carried residues of previous acaricide applications. Terminals were pruned to shoots of five to eight leaves; each shoot was considered a replicate. Six to 10 replicates were used for each dosage per orchard. Shoots were dipped for 3 sec in a suspension of the test acaricide, then placed in an Erlenmeyer flask of water. Counts of live motile mites were made after 72 h, except for one test with CG 121633 (96 h), and Vendex (120 h). Control shoots were dipped in water containing a drop of (B-1956). The effect of treatment is expressed as % reduction in number of live mites on treated foliage compared to controls. Higher dosages were equivalent to field rates for acaricides, and lower rates were 0.25 field rates. Field tests were conducted at 2 locations, the Rutgers Tree Fruit Research Center at Cream Ridge, N.J. Treatments were applied (Hurff) at Monroeville, N.J. Treatments were applied to single-tree plots of a spur-type Red Delicious with four replicates per treatment. Trees were sprayed to runoff, using a hydraulic sprayer equipped with a handgun. Treatments were applied on 28 Jul. at Cream Ridge and 5 Aug. at Hurff’s and counts were made after 72 h. Mite population estimates were made by randomly picking 10 leaves per replicate and counting mobile mites.