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Treatments were applied to 16 year old 'Triple Red Delicious' trees using single tree plots arranged in a randomized block design and replicated 4 times. Trees were sprayed to runoff using a Bean hydraulic sprayer operating at 400 psi. All plots were inoculated twice (29 May and 12 Jun) with mite infested water sprouts (10 per replicate) which were taped to existing foliage. Insecticides used during the season follow; fungicides, nutrient sprays, herbidices, etc. used are listed separately. All plots were oversprayed with Pounce 3.2 EC, 814 kg/ha (7.5 lb/A) on 9 Apr and 10 May; Dipel 3.36 kg/ha (3 lb/A) 1 May; and Sevin 50 W 3.36 kg/ha (3 lb/A) 25 Jul to reduce predator numbers in the mite plots. Morestan 25 W, 28.38 g/ 189.25 1 (1 oz/50 gal), was applied on 2 Apr (pink spray). All other miticide plots were sprayed on 2 Jul. Populations of mites did not reach levels requiring treatment after 2 Jul. One hundred apples per replicate were picked at random at harvest and graded on a scale from 0-5 for both stem end and side russetting where 0 = no russetting and 5 = completely russetted. These data were used to place each fruit in the appropriate USDA grade (extra fancy, fancy, No. 1, utility). Each fruit was also examined for injury by RBLR, TABM, CM, and miscellaneous Lepidoptera (LEP) (primarily gypsy moth). No significant differences between treatments were found.

Pyrellin, Pyrellin + Omite 30 W, Omite 30 W and water were applied as airblast treatments to five year old ‘Ace Red Delicious’ apple trees. The young trees in this planting, widely spaced for experimental purposes (6.1 meters X 7.32 meters), were not mature size and consequently each received only .5 gal (1.89 liters) of the concentrate spray mixture. Two applications of the treatments were applied with a truck mounted Swanson D400 airblast sprayer calibrated to deliver 50 gal/A (76.62 liters/ha) to mature semi-dwarf MM 106 trees. Treatments were applied 18 Jun and 5 Jul. A randomized block design was used in this four treatment, five replicate experiment. Counts were made following the Henderson-McBurnie procedure of mite brushing. The sample size was 20 leaves/replicate/sample date.

A randomized block design was used in this for treatment, four replicate experiment conducted in a 9-year-old block of‘Lawspur Rome’ at the Research Farm Orchard. Treatments were Kelthane 50W .64 kg/ha + Latron AG 44; Kelthane 50W .64 kg/ha; Latron AG 44 + water (50 gal/acre = 189.27 liters/ha) and a water control 50 gal/acre (189.27 liters/ha). In all treatments the amount of Latron AG 44 used was that sufficient to lower the spray mixture to a pH of 6.5. Sprays were applied on 15 Jul with a power-take-off driven FMC (model 252S) sprayer calibrated to deliver 50 gal/acre (6 x concentration). Replicates of each treatment consisted of three trees in a row (data collected from the center trees only). Buffer rows of untreated trees separated rows of treatment trees. Insect predators were counted during a three minute visual observation of the center tree in each replicate on 17 Jul (2 days after treatment). Mite data were generated using the Henderson-McBurnie method of brushing 20-leaf samples from each replicate on each sample date.

Treatments were applied to 20 year old ‘Red Delicious’ trees in a commercial orchard. Plots were arranged in a randomized block design with 5 replications of three trees in a row. The first treatment spray was applied with a power take off driven FMC sprayer (model 252S) and the second with a truck mounted Swanson D400 Airblast sprayer. Both sprayers were calibrated to deliver 68.25 liters/ha (50 gal/acre). The pH of all treatment mixtures was adjusted to 6.0 before application by adding one of the acidifying agents (Latron AG 44M, Spray Aid, or cider vinegar) as noted in tables. All data were taken from the center tree in each replicate plot. Rows of replicates were separated from each other by an unsprayed guard row. Mite pest and predator counts are the results of microscopic examination of twenty leaves collected from the center tree in each replicate plot (Henderson-McBurnie technique). Insect predator counts presented were collected during three minutes of visual observation of the same center trees. Two applications of all treatments were made (16 Jul and 7 Jul). Before the 16 Jul treatment mites density was estimated at 6.5 ERM/leaf, 46 ERM eggs/leaf, 0 TSM/leaf and 3 TSM eggs/leaf. The estimate was derived from a count of mites on 20 leaves randomly selected from the orchard. Two timed three minute observations of SP were made, one on 30 Jun (14 days post 1st treatment) and the second 14 Jul (7 days post second treatment).

The experiment was conducted in an orchard of 16 year old ‘Spur Red’ Delicious apple trees on MM 106 roots. Treatments were placed in alternating rows, with the intervening unsprayed rows serving as guard rows, arranged in a randomized complete block design. Each replicate (4 per treatment) consisted of three adjacent trees. Data was only taken from the center tree of each replicate. Treatments were applied with a power take off driven FMC (model 252S) airblast sprayer calibrated to deliver 50 gpa (76.62 liters/ha). Delayed dormant 60 sec. oil (6 gal./acre) was applied to two treatments on 27 Apr. One treatment contained only oil but the other had Kinetic EC (16 oz./acre) combined with oil. Two control plots were established, one received two inoculations of ERM and one did not. The inoculations made to all plots except as noted above consisted of taping 10 mite infested apple shoots (collected in a heavily infested commercial orchard) to limbs on the periphery of each test tree. Inoculations were made on 24 May and 4 Jun. Other treatments were applied on 21 Jun and 28 Jun. Predator data (16 Jul) was collected during a three minute observation of the canopy. Mite data were developed by collecting leaf samples (20 leaves) and following the standard Henderson-McBurnie mite brushing procedure.

Insecticides were applied to 10 year old ‘Ida Red’ apple trees on MM III rootstocks. Five three row plots were randomly selected and one was assigned to each treatment. The two outside rows served as guard rows. Data were collected from four or five replicate trees randomly selected from the middle rows in each plot. Treatments were applied with a power take off driven FMC (model 252S) sprayer calibrated to deliver 50 gpa (76.62 liters/ha.), a 6x concentration for this orchard. Treatments were applied on 27 Apr, 21 May and 6 Jul. Other insecticide sprays included a delayed dormant spray of superior oil (60 sec.) applied to the control and the Lannate + Guthion plots on 8 Apr. Guthion 35W (2 lb./A) was added to all sprays (including the 6 Jul treatment) on the NTN33893 plot on and after 18 Jun. Other materials used for orchard maintenance are given later in a table. Insect predators were sampled in a three minute visual count per tree. RAA & AA (complex of AA & SA) were counted as number of infested terminals in 10/replicate, or number of infested water sprouts in 10/replicate, or number in 10 terminals/replicate on which the terminal leaf was infested. Tentiform leafminer and WALH data indicate the number of leaf mines or leafhoppers/leaf present when ten leaves/replicate were examined. Mite data were generated using the Henderson McBurnie method of brushing 20-leaf samples from each replicate. Mites and eggs were counted with a binocular microscope. Data were transformed to either log 10x +1 or square root X + .5 for analysis.

A large commercial apple grower reported failure in attempts to control TABM with airblast applications of Penncap M (2 pt/acre) combined with methomyl (3 pt/acre). At the time of the grower applications larval hatch had begun and most larvae were in the first or second instar. By the time larvae were entering the third instar (10 days after spray application) it was apparent that commercially acceptable control had not been achieved. In 1992 this grower also had poor control when Penncap M was applied to suppress redbanded leafroller and experiments showed that tolerance of Penncap M was present in the resident RBLR population (Horsburgh et al. 1992). This laboratory bioassay was begun on 3 Sep to determine tolerance of the TABM population to Penncap M and other insecticides. Seven treatments (including a water control) were selected and rates calculated on the basis of 300 gal of spray being applied per acre. The appropriate dosage of pesticide for each treatment was mixed with 1 gallon of 77°F water in clean 1 gallon battery jars. Twenty plastic petri dishes containing moistened filter paper were prepared and served as individual cages for twenty 3rd instars per treatment. The larvae, on single leaves, were immersed in the appropriate solutions for five seconds and the leaf placed on the moist filter paper. The petri dish cover was put in place and the cages held at room temperature (80°F) for the duration of the test. All larvae were examined at 24 hour intervals and mortality was recorded. Death of larvae was assumed when no movement was observed when the larvae were gently prodded with a blunt steel probe.

Four pesticides, carbaryl (Sevin XLR 3.75 ml per liter [3 pt/100 gal]); methyl parathion (Penncap M 7.5 ml/liter [1 pt/100 gal]); chlorpyrifos (Lorsban 50W 4.78 g/liter [3.99 lb/100 gal]); azinphosmethyl [Guthion 35W 4.78 g/liter] + methomyl (Lannate 7.5 ml/ liter [3.89 lb + 3 pt/100 gal respectively]), and a water control were evaluated (6X concentration) where X = 50 gal/acre in this experiment. RBLR larvae of various sizes and ages were collected in their leaf spin-ups from a commercial orchard where populations were sampled in our 1991 studies. Foliage used in the experiment was collected from unsprayed apple trees at the experiment station in Winchester. Solutions of each treatment pesticide were prepared in 1 gal jars. Twigs bearing more than 40 leaves (for each treatment) were dipped in the appropriate solution for 15 s and air dried in a fume hood. Twenty cages (1 larva per cage) per replicate were prepared as follows: two 9 dram plastic bottles made up the basic cage unit, one filled with water served as the basal unit. Two plastic vial covers with a small (.64 cm) hole centered in each were stapled together and put in place on top of the base vial. Two apple leaves (previously dipped and dried) were placed so as one leaf lay in close proximity to the other with the petioles extending through the container caps into water in the basal container. The point where the petioles passed through the cap was tightly closed with absorbent cotton to prevent larval escape. One field collected larva was gently removed from its spin-up with a camel’s hair brush and placed between the two leaves in each cage. Finally, the second ventilated plastic vial (which had a 3/4-in hole cut in the bottom that was covered with glued-in-place 100 mesh nylon screening) was inverted over the basal vial and snapped into place in the uppermost of the two previously prepared plastic covers. All cages were held in a room under normal light at 80°F (144°C). Larvae were examined after 24, 48, 72, 96, 120, 144 h for mortality. Death was determined if the larva exhibited no movement after being probed gently.

Two tests were conducted to gather preliminary data on the possibility of controlling RBLR adhering to fruit before it is placed in storage. Since most apples enter packing sheds via a water dump, and since the insecticide under test is registered for use on harvested produce, including fruit, adding the toxicant to the dip water appeared to be a possible, practical control method. Test No. 1: Thirty apples with RBLR larvae adhering to the surfaces of the fruit were obtained from a bin of drop apples collected from under the trees in a commercial apple orchard on 20 Oct. Larvae were disturbed as little as possible during collection and leaves covering the larval sites were left in place. Each infested apple was marked by sticking an aluminum shingle nail into the fruit some distance from the location of the insect. The infested fruit was randomly distributed among the fruit filling a one bushel packing crate. Fifty gallons of untreated well water was placed in a galvanized tank and 12 fl. oz. of Pyrellin E.C. was thoroughly mixed with the water. A wooden cover was held on top of the fruit to keep it in the crate while the crate was immersed in the pesticide solution for one minute. Following dipping, the crate was placed on an outside, roofed, loading dock where it remained until the larvae were examined twenty-four hours later. Test No. 2: This test, conducted on 26 Oct, was similar in most respects to test No. 1. However, the apples came from a different orchard. In test 2, a plastic garbage bag was placed under the crate after dipping in an attempt to capture exiting larvae. Prior to this test the grower had reported a heavy population of tufted apple bud moth, however it was found to be RBLR when larvae from the test were collected.

Some fruit growers in Virginia experienced difficulty in controlling leafhoppers on apple in recent years. Treatments were applied to runoff with a Bean hydraulic sprayer operating at 400 psi on 8 May. Test trees were 4 year old 'Ace Red Delicious.' Plots (single trees) were arranged in a randomized block design. Each treatment and the control was replicated 4 times. The total number of live leafhoppers on 20 leaves from each replicate was determined on 9 May.

The effect of the insecticides Lorsban 4 E, Guthion 35 W, and Lorsban 50 W was evaluated on the fruit on mature apple trees. Materials at rates and times noted in the table were applied to run off with a Bean hydraulic sprayer operating at 400 psi. There were 4 single tree replicates of each treatment. All treatments and the control received 7 fungicidal sprays of Rubigan 6 oz/A + Benlate 6 oz/A. Twenty fruit per replicate were examined on the trees and evaluated for side and stem end russet. These apples were placed into grade categories according to U.S. Grade standards. No phytotoxic symptoms were observed at the time of the field examination 27 Jul.

Treatments were applied to 8-yr-old Nittany trees (on MM7A roots) using single tree plots arranged in a randomized block design and replicated 4 times. Trees were sprayed to runoff using a Bean hydraulic sprayer operating at 400 psi. Plot 1 was sprayed with 60 sec oil at delayed dormant (DD) and Carzol 92 SP at petal fall (PF). Plot 2 received Morestan in the pink (P) and Carzol at PF, and plot 3 was treated with Morestan 25 WP at P and Carzol SP after the ERM population reached a threshold of 3 mites/leaf. All other treatments were applied when mite populations in the orchard reached this predetermined threshold (T). To estimate pretreatment density, 10 randomly selected leaves (1/tree) were picked at chest height while walking diagonally across the orchard. Mites and eggs were counted with the aid of a binocular microscope. The count of 24 May averaged 3.3 mites and 9.5 mite eggs/leaf. During the remainder of the season mites and eggs were counted by randomly selecting 20 leaves/replicate, brushing them onto a sticky glass plate and counting all motile mites and viable eggs with a binocular microscope. Mite predators were destroyed prior to treatment with applications of permetherin. When predators began to appear in the plots, they were counted during a 3 min observation of each tree and recorded.

Treatments were applied to 7-yr-old Rome trees using single tree plots arranged in a randomized block design and replicated 4 times. Trees were sprayed to runoff using a Bean hydraulic sprayer operating at 400 psi. Morestan 25 W was applied to one plot at pink stage of bud development. Sevin 50 W and 60 sec oil were applied to one plot at normal thinning time. Other treatments were applied on 2 Jun. Mites and eggs were counted by randomly selecting 10 leaves/replicate, brushing them onto a sticky glass plate and counting all motile forms and viable eggs with a binocular microscope. Mite predators were kept out of these plots during early season with several applications of permethrin.

Experimental insecticide treatments were applied in a comparative test to 7 yr old Lawspur Red Rome trees. A randomized block design was used and each treatment was replicated 4 times. Trees were sprayed to runoff using a Bean hydraulic sprayer operating at 400 psi. Treatments were applied on 25 May (PF), 19 Jun, 7-10 Jul and 9 Aug. All trees were sprayed on 4 Apr and 17 Apr with Pounce 3.2 E. Mite populations were evaluated by randomly selecting 10 leaves/replicate, brushing onto a sticky glass plate and counting all motile forms and viable eggs with a binocular microscope. Stethorus punctum and Orius insididuous were evaluated during a 3 minute observation of each tree. Effects on the PLH were evaluated by counting terminals with visible damage on each tree. AA populations were evaluated in late Jun by examining 10 randomly selected terminals/tree to determine the number of terminals infested. Each tree was then rated 0-5 to account for the severity of the infestation. The severity rating was then multiplied by the number of infested terminals to arrive at an overall treatment effect. All drops were examined for damage by direct pests and discarded periodically from mid-Aug until harvest. Harvest samples were collected (50/rep) on 9 Oct and visually inspected for fruit feeding insect damage. Fruit finish was rated from 0-5 on each apple.

The functional responses of all feeding stages of Leptothrips mali (Fitch) to various densities of selected Panonychus ulmi (Koch) stages were determined in the laboratory at 23.9 ± 1°C. Functional response data were obtained for the following L. mali-P. ulmi combinations: first-stage larvae of L. mali with P. ulmi eggs and adults, second-stage larvae or adult female L. mali with adult P. ulmi. To estimate the relationship between the number of prey killed and prey density for the selected predator-prey combinations, various mathematical models were fit to the data. No functional response was found when first-stage larvae were provided adult female P. ulmi. A sigmoid curve best explained the relationship in all other situations. Search rate increased between the two lowest prey densities when adult thrips were provided adult mites. No such increase was observed with other L. mali-P ulmi combinations; search rate remained constant. Therefore, for these other stages, the type III response obtained cannot be explained on the basis that the search rate increases over an initial range of low prey densities. A possible explanation may be interference-stimulation of the predator by the prey above some threshold prey density.

The Pherocon lC trap baited with a rubber septum impregnated with 2.5 mg pheromone captured the greatest number of Platynota flavedana Clemens moths. Traps hung at 2.1 and 3.0 m captured the greatest number of P. flavedana . Trap heights of 1.2, 2.1, and 3.0 m caught the greatest number of P. idaeusalis (Walker) moths. The outsidethe-canopy trap position captured more P. flavedana moths, whereas the within-canopy trap location caught the greatest number of P. idaeusalis moths. Traps placed in the west portion of the tree captured the greatest number of P. flavedana moths. P. idaeusalis moth catches were not influenced by compass quadrants.

Methomyl in seven concentrations ranging from 0.051 to 0.204 kg (AI)/378.5 liters of water was evaluated against eggs of insect and mite pests and beneficial insects associated with apples. Platynota flavedana Clemens (Lepidoptera: Tortricidae), Aphis spp. and Dysaphis plantaginea (Passerini) (Homoptera: Aphididae), and Argyrotaenia velutinana (Walker) (Lepidoptera: Tortricidae) eggs were highly susceptible to the material. Eggs of Cydia pomonella (L.) (Lepidoptera: Tortricidae) were less susceptible. Panonychus ulmi (Koch) (Acari: Tetranychidae) eggs were not susceptible. Eggs of beneficial syrphid flies, Aphidoletes aphidimyza (Rondani) (Diplera: Cecidomyiidae), Leptothrips mali (Fitch) (Thysanoptera: Phlaeothripidae), and Stethorus punctum (LeConte) (Coleoptera: Coccinellidae) were highly susceptible to methomyl. Eggs of Orius insidiosus (Say) (Heteroptera: Anthocoridae) were less susceptible. Chrysopa spp. (Neuroptera: Chrysopidae) eggs appeared to be unaffected by the chemical.

The interspecific interactions of 5th-instar Orius insidiosus (Say) and 2nd-instar larvae of another mite predator, Leptothrips mali (Fitch), was studied in the laboratory. L. mali is a potential prey for O. insidiosus , but has a defensive anal secretion which repels predator attacks. Most contacts between well-fed O. insidiosus and L. mali resulted in mutual avoidance. Most attacks by O. insidiosus were unsuccessful, especially if the approach was from the rear. Contact with the thrips' anal secretion resulted in immediate repelling of O. insidiosus , with subsequent cleaning activity lasting 1 to 3 min. This study indicates that these two predators are compatible, especially in the presence of another food source such as the European red mite.

Experimental insecticide treatments were applied in a comparative test to Redspur Delicious trees on 14 Apr (pink), 30 Apr (petal fall), 22 May, 12 Jun, 11 Jul, 2 Aug and 22 Aug. Treatments were applied with a Bean 35 gal/min hydraulic sprayer operating at 400 psi. Single tree treatments were used and replicated 4 times in a randomized block design. Trees were sprayed to runoff. White apple leafhoppers were counted on 13 May by randomly selecting 10 leaves per replicate and counting all adults and nymphs present. Effects on mite populations were evaluated by randomly selecting 25 leaves per replicate on several dates throughout the season, brushing with a modified Henderson-McBurnie brushing machine onto glass plates and counting mites and eggs under a binocular microscope. Stethorus punctum counts were made on 2 Jul and 21 Jul by counting adults and larvae in a timed count of 3 minutes per replicate. A sample of 50 apples per tree was examined on 19 Aug to evaluate codling moth damage. Spotted tentiform leafminer populations were evaluated for season long control on 25 Aug by counting mines found on each tree in 3 min. A sample of 100 apples per tree was harvested on 15 Sep to evaluate insect damage and to rate fruit finish. Fruit finish was rated from 1 to 5 (1 being best).

Leptothrips mali (Fitch) (Thysanoptera: Phlaeothripidae) was studied in the laboratory with the European red mite, Panonychus ulmi (Koch), as prey. Aspects of its development and biology were determined. Mean number of days required for development of each stage at 23.9°C were: egg, 7.5; first larva, 5.7; second larva, 5.4; prepupa, 1.0; pupa I, 1.5; pupa II, 4.0; total (egg to adult), 25.6. An inverse relationship was found with temperature and development times for the egg, first- and second-stage larvae, pupa II, and total (egg to adult) at 18.3, 23.9, and 29.4°C. The mean preoviposition period (range = 5–7 days) of mated and unmated or field-collected (FC) and laboratory-reared (LR) females did not differ. Mean numbers of eggs per female were: mated LR, 13.0; mated FC, 28.0; unmated LR, 11.7; and unmated FC, 45.1. Mean longevity of unmated females (LR and FC = 50.1 and 54.2 days, respectively) did not differ from that for mated females. L. mali completed development on Golden Delicious apple pollen in 23 days (first larva to adult), which was slower than on diets containing various stages of P. ulmi.

Egg and nymphal development of Orius insidiosus (Say) was studied at 17, 23, 29, and 35°C. There was a linear relationship between development rate (1/days) of O. insidiosus and temperature. Developmental threshold temperatures were calculated as 10.2°C for eggs and 8.9, 7.5, 10.7, 12.4, and 9.9°C for instars 1–5, respectively. A 10.0°C developmental threshold was determined for total nymphal development. Mean degree-day requirements for development were calculated for all stages studied. Laboratory and field observations established that a number of small, soft-bodied insects and mites as well as the eggs of several Lepidoptera are acceptable as prey. O. insidiosus also fed on other beneficial species including predaceous thrips and mites. A number of general orchard predators, particularly spiders, chrysopids, and other predaceous Heteroptera, were found to prey upon O. insidiosus . Numerous weeds and crops serve as alternate sites for O. insidiosus populations. Corn and alfalfa adjacent to apple orchards in Virginia apparently serve as a reservoir for O. insidiosus throughout the season. Thistles ( Carduus spp.) harbor large numbers of O. insidiosus , which prey on thrips. These natural and cultivated alternate sites may be important to management of O. insidiosus populations.

The species composition and habitat associations of spiders were studied in one abandoned and 5 commercial apple orchards in central Virginia. Sixty-eight identifiable species were recorded from all orchards. The abandoned orchard contained 63 species while 11–17 species were found in individual commercial orchards. The Salticidae, Philodromidae, Thomisidae, Theridiidae, Anyphaenidae, and Dictynidae comprised 75–92% of the total spiders collected from each orchard. The proportions of hunting spiders found in all but one commercial orchard were similar to that found in the abandoned orchard. The many species of spiders encountered in each orchard exhibited specific habitat preferences and segregated the tree into numerous niches. Since many orchard insect pests often occupy several of these niches, different spider species may act in a complementary manner to suppress such insect pest populations.

Development of Platynota flavedana Clemens and P. idaeusalis (Walker) on a meridic diet was observed at constant temperatures in the laboratory. Lower developmental threshold values for egg, larval, and pupal stages of P. flavedana were 10.6, 8.6, and 9.0°C, respectively. Lower developmental threshold values of 9.7, 7.0, and 8.5°C were estimated for egg, larval, and pupal stages of P. idaeusalis , respectively. Averages of 101.5 DD10.6, 379.6 DD8.6, and 126.0 DD9.0 were required for development of egg, larval, and pupal stages of P. flavedana , respectively. P. idaeusalis required 104.7 DD9.7 442.7 DD7.0, and 132.2 DD8.5 to complete development in the egg, larval, and pupal stages, respectively. Differences in rate of development were observed between food sources for both species.

The functional response of Orius insidiosus (Say) to densities of the European red mite, Panonychus ulmi (Koch), was studied at 18.3, 23.9, 29.4, and 35.0°C with prey densities of 5–80 mites per cage. Mite consumption was recorded during five, 3-h intervals during the day. O. insidiosus exhibited a functional response and increasing temperatures resulted in increased feeding at most prey densities. Data provided a good fit to both type-2 and type-3 functional response models.

Nymphal and adult Diaphnidia capitata (Van Duzee) have long been recognized as predators of Panonychus ulmi (Koch) and Tetranychus urticae Koch. The eggs and oviposition sites preferred by this species are described herein to supplement available descriptions of the eggs of mirid predators of spider mites.

M0070616, a pyrethroid insecticide, was tank mixed with variable rates of Vendex and applied to mature semi-dwarf ‘Red Delicious’ trees with a Bean 35 gal/min hydraulic sprayer operating at 400 psi. Single tree treatments were used and replicated 4 times in a randomized block design. Trees were sprayed to runoff. Application dates were 4 Apr (pre-pink), 18 Apr (pink), 1 May (petal-fall), 21 May, 3 Jun, 27 Jun, 10 Jul and 9 Aug. Each rate of Vendex plus M0070616 was tested as a full season treatment and as a post-bloom treatment. A standard treatment (Lorsban) was included and the post-bloom plots of M0070616 plus Vendex were treated the same as the standard for pre-bloom applications. ERM was evaluated periodically throughout the season by randomly selecting 25 leaves/trees, brushing with a modified Henderson-McBurnie mite brushing machine onto glass plates and counting motile mites and eggs with a binocular microscope. Full-season and post-bloom treatments of M0070616 alone, as well as the unsprayed check required 1 application of Kelthane 4F (16 fl ox/100) on 18 Jun to reduce ERM to manageable levels.

To assess the effects of Lannate-L on the eggs of beneficial insects seven treatments and a water control were used in each of 6 experiments. The treatment rates (litre (ounces) of Lannate-L/378.5 litre (100 gallons) water) were: (I) 0.95 litre (32 ounces); (2) 0.83 litre (28 ounces); (3) 0.71 litre (24 ounces); (4) 0.59 litre (20 ounces); (5) 0.47 litre (16 ounces); (6) 0.35 litre (12 ounces); (7) 0.24 litre (8 ounces); (8) water control.

The individual or joint potential impact of Leptothrips mali (Fitch) with Stethorus punctum LeConte or Orius insidiosus (Say) on the European red mite ( Panonychus ulmi (Koch)) was evaluated in the laboratory. At a mite density of 45/arena, L. mali with S. punctum killed significantly more P. ulmi than L. mali or S. punctum alone. No difference was observed in total mites killed when the combination of L. mali or O. insidiosus was compared with individual L. mali and O. insidiosus . In 75% of replicates where L. mali was combined with O. insidiosus , the latter killed and consumed the thrips.

During 1967 Hyaliodes vitripennis (Say) proved to be an important predator of Panonychus ulmi Koch and Tetranychus urticae Koch in an experimental orchard. The eggs of this predator, described herein, are destinctive for the species. Observations on oviposition sites for the overwintering eggs are also included.

Experimental insecticide treatments were applied in a comparative test to mature semidwarf trees on 5 Apr. (delayed dormant), 27 Apr. (pink), 25 May, 8 June, 23 June, 19 July, 3 Aug., and 25 Aug. Treatments were applied with a Bean 35 gal/min hydraulic sprayer operating at 400 lb/in2. Single tree treatments were replicated four times in a randomized block design. Trees were sprayed to runoff. White apple leafhopper populations were evaluated on 2 7 May by counting nymphs and adults on 10 leaves per replicate. European red mite populations were evaluated on 8 July, 27 July, and 22 Aug. by randomly selecting 10 leaves per replicate and counting motile mites with the aid of a hand lens. Stethoruspunctum (LeConte) was evaluated on 28 July and 23 Aug. by counting larva and adults in a timed count of 3 min per replicate. Fruit evaluations for insect damage were completed at harvest (30 Sept.) by examining 50 randomly selected fruit from each replicate. Percent clean fruit for each treatment was recorded. Fruit finish was rated on a scale of 1 (lowest) to 5 for each apple and averaged for the four replicates.

Treatments were applied in a comparative test to mature semi-dwarf Golden Delicious trees on 28 Jun with a Bean 35 gal/min hydraulic sprayer operating at 400 psi. Single tree treatments were used and replicated 4 times in a randomized block design. Trees were sprayed to runoff. Mite and egg populations were evaluated by randomly selecting 25 leaves per replicate in each treatment, brushing mites and eggs onto glass plates with a modified Henderson-McBurnie mite brushing machine and counting with a binocular microscope. A pre-treatment evaluation on 26 Jun showed an average of 1.54 mites and 4.55 eggs/leaf. Posttreatment evaluations were done on 3 Jul and at weekly intervals throughout Jul. SP populations began to increase during mid Jul on some treatments and were evaluated on 25 Jul by counting all adults and larva in a timed count of 3 min/replicate. Effects of the treatments on SPLM were evaluated by recording the number of leafmines observed in a timed count (3 min/replicate) on 25 Jul.

Materials were applied to mature, standard York trees replicated four times in single tree plots in a randomized block design. Sprays were applied to runoff on Aug 31 to coincide with peak egg deposition and on Sep 10 when larvae were in the early instars. Treatments were applied with a Bean 35 gal/min (132.49 liters/min hydraulic pump operating at 300 psi (21.09 Kg/cm2). On Sep 19 200 apples/tree (800/treatment) were randomly selected and checked for both early and late season damage by the leafroller complex.

Treatments were applied to mature trees using single-tree plots arranged in a randomized block design and replicated 4 times. Trees were sprayed to run-off using a Bean 35 gal/min hydraulic sprayer operating at 300 psi. Morestan 25 W was applied at pink stage of bud development (15 Apr), and other treatments were applied on 29 Jun when average mite counts were 3.83/leaf. Mites and eggs were counted by randomly selecting 25 leaves/replicate, brushing onto glass plates with a modified Henderson-McBurnie brushing machine, and counting all motile forms and viable eggs with a binocular microscope. Due to the slow buildup of mite populations in this block, trees were seeded on 3 Jun by taping mite-infested shoots from several locations into each tree. Mite predators were kept at low levels during the early season with sprays of Asana, Sevin, and Lannate.

Treatments were applied to mature York trees using single tree plots in a randomized block design and replicated 4 times. Trees were sprayed to runoff using a Bean 35 gal/ min hydraulic sprayer operating at 400 psi. Mites and eggs were counted by randomly selecting 25 leaves/replicate, brushing onto glass plates with a modified Henderson-McBurnie brushing machine and counting all motile forms and viable eggs with a binocular microscope.

Treatments were applied to mature York trees in a comparative test on 21 Jun, 29 Jun, 16 Aug and 28 Aug. Single tree treatments were used in a randomized block design and replicated 4 times. Trees were sprayed to runoff using a Bean 35 gal/min hydraulic sprayer operating at 400 psi. Because of high mite populations, Vendex 4F 8 fl oz/ 100 gal was added to all treatments on 21 Jun and 29 Jun. A preliminary evaluation of leafroller injury to fruit was done on 15 Aug by checking 50 apples/ replicate. Fruit were examined on trees and total injuries by first generation leafrollers were recorded. Fruit samples (100/rep) were harvested and examined on 2 Oct for leafroller injury.

Experimental insecticide treatments were applied in a comparative test to mature semi-dwarf York trees on 1 May (pink), 21 May (petal-fall), 6 Jun, 20 Jun, 6 Jul, 19 Jul, 2 Aug, 15 Aug and 29 Aug. Treatments were applied with a Bean 35 gal/min hydraulic sprayer operating at 400 psi. Single tree treatments were used and replicated 4 times in a randomized block design. Trees were sprayed to runoff. RAA populations were evaluated on 16 May by counting all colonies found in 3 min/tree and opening the leaves to determine survival from the 1 May treatments. Aphid colonies were counted again on 4 Jun (3 min/tree) to determine increases in population and effectiveness of the 21 May treatment sprays. WHAL populations were evaluated on 16 May by counting nymphs and adults on 25 leaves per replicate. Apple aphid populations were examined on 28 Jun by checking for live aphids on 10 randomly selected terminals/replicate. ERM populations were evaluated on 11 Jun, 26 Jul and 6 Aug by randomly collecting 25 leaves/replicate, brushing with a modified Henderson-McBurnie mite brushing machine onto glass plates and counting mites and eggs with the aid of a binocular microscope. SP counts were made on 7 Aug by counting adults and larva in a timed count of 3 min/replicate. On 8 Oct, 400 apples/treatment (100/rep) were harvested and evaluated. All significant damage was the result of feeding by the leafroller complex (RBLR, VL, TABM). Percent clean fruit is shown and allows for light damage from other pests. Average fruit size was measured and a finish rating of 1 to 5 (5 being worst) was given each apple.

Vydate (oxamyl; methyl N’, N’ dimethyl-N[methylcarbamoyl) oxy]-l-thioox-amimidate) and Sevin (carbaryl; 1 napthyl-N-methyl carbamate) did not give significant thinning of ‘Starkrimson Delicious’ apples (Malus domestica Borkh.) when applied as airblast treatments in 3 years of tests. Neither multiple applications nor the addition of a 70-sec superior spray oil gave significant thinning compared to untreated controls. Airblast treatments of these materials on ‘Golden Delicious’ were effective but were inadequate to reduce crop load to the desired level. The data suggest that Vydate and Sevin are inadequate as thinners if applied with airblast machines. Ethephon treatments caused erratic responses at the rates and timings used. Sevin applied for thinning caused an increase of European red mites and their eggs.

Treatments were applied to run-off with a hand-gun at 14.06 kg/cm2 (200 psi) and 132.5 litres/min (35 gpm). Plots were arranged in a randomized block design with 4 replicates. Each replicate was represented by a different cultivar (Triple Red Delicious, Golden Delicious, Double Red Stayman and Commander Red York). Unsprayed buffer trees were left between all replicates. A pretreatmenf (Jul 7) and 4 post-treatment mite counts (Jul 15, Jul 22, Jul 29, and Aug 5) were made. Random samples of 20 leaves/free were brushed with a mite brushing machine and mites and mite eggs were counted. Data were recorded as mites or mite eggs/leaf. All data were transformed to log10 (X+l). ANOVA and Duncan’s Multiple Range Test were used for the analyses. Plictran 50W was the standard.

Treatments were applied on Jun 8 following a Jun 5 count, analysis of which showed no significant differences (P = .01) in mite populations. Single tree plots were arranged in a randomized block design and replicated four times. Trees were sprayed to runoff using a Bean 35 gal/min (132.49 litres/min) hydraulic pump operating at 300 psi (21.09 kg/cm2) for this spray and two subsequent test sprays on Jun 23 and Jul 16. (Note: On the dinobuton plot the first spray was delayed until Jun 29.) Mites and eggs were counted at approximately weekly intervals from Jun 5 to Aug 3, on randomly selected 25 leaf samples using 2 modified Henderson-McBurnie leaf brushing technique. Mite predators were counted on Jul 14 on five limbs on each tree by jarring them onto a one square meter sheet of white muslin by striking each limb 5 times with a rod. In addition to the materials being evaluated, the following were used on these trees: pre-bloom, chlorpyrtfos (Lorsban), oil, benomyl (Benlate) and metiram (Polyram); bloom, benomyl (Benlate) and metiram (Polyram); post-bloom, benomyl (Benlate), metiram (Polyram), azinphosmethyl (Guthion), carbaryl (Sevin) as thinning agent, parathion (Penncap-M), methomyl (Lannate), Alar, Dikar, and captan.

The predaceous mirid Deraeocoris nebulosus (Uhler) is found on more than 50 species of ornamental trees and shrubs where it feeds on several important pest species (Wheeler et al. 1975). It is a common mite and aphid predator in commercial apple orchards in Virginia (Parrella et al. 1978). Wheeler et al. (1975) described the nymphal stages and biology, but made no mention of the egg or oviposition site. We describe the egg and oviposition site which we discovered while studying various predators of the European red mite, Panonychus ulmi (Koch), in Virginia apple orchards. Eggs and oviposition sites of other predaceous mirids associated with apple have been described (Kullenberg 1942; Collyer 1952, 1953; Sanford 1964; Horsburgh and Asquith 1968, 1970).

Insecticide treatments were applied in a comparative test to mature ‘York’ trees on 6 Apr (only treatments scheduled for delayed dormant application), 14 Apr (P, pink), 11 May (PF, petal fall), 1 June (1C, first cover), 17 June (2C, second cover), 8 Jul (3C, third cover), 28 Jul (4C, fourth cover), and 31 Aug (5C, fifth cover). Treatments were applied with a Bean 35 gal/min hydraulic sprayer operating at 300 psi. Single-tree treatments were replicated 4 times in a randomized block design. Trees were sprayed to run-off. AA populations were evaluated on 21 Jun by randomly selecting 10 growing terminals/replicate, rating aphid populations on a scale of 1-5, and counting aphids on the fourth distal leaf. ERM populations were evaluated on 13 Jul and 15 Aug by randomly selecting 25 leaves/replicate, brushing them with a modified Henderson-McBurnie brushing machiin . and cropting motile mites and viable eggs with a binocular microscope. WALH damage was evaluated by rating foliage on each tree on a scale of 1 (low) to 5 (high). Insect feeding on fruit was evaluated by harvesting 100 apples/replicate on 3 Oct and visually inspecting each apple.

Egg masses laid by summer generation Piatynota spp. females were collected on Aug 18 from Red Delicious trees in a commercial apple orchard in Nelson Co., VA and brought back to the laboratory for study. Treatment rates ranged from 0.47 litre (16 oz) to 0.06 litre (2 oz) of Lannate 1.8 L/378.5 litres (100 gal) plus a water control. The leaf clusters bearing Piatynota spp. egg masses were dipped in the respective treatment solutions and were maintained in 50-dram clear plastic vials until egg hatch. One egg mass was used per vial and four, one-vial replicates were used per treatment. Data were recorded as percent hatch. Apple leaves bearing eggs of P. ulmi were collected from a research orchard in Winchester, VA on Aug 4 and were transported to the laboratory. Irregular-sized Teaf sections containing mite eggs were cut out with scissors and affixed to double-coated Scotch tape on a microscope slide. Ten eggs were used per slide and three replicates were used per treatment. Prepared slides were dipped in methomyl treatments which ranged from a rate of 0.95 litres (32 oz) to 8.52 litres (288 oz) of Lannate 1.8 L/378.5 litres (100 gal) water plus a water control. When eclosion ceased, data were recorded as percent hatch. Adult L. pomonella, reared from field collected larvae-infested apples, oviposited on waxed paper in the laboratory. Sections (7 mm diameter) of the paper with egg(s) in situ were removed with a paper punch and stuck on double-stick Scotch tape on a microscope slide. Ten eggs were affixed to each slide and three slides were used per treatment.

Experimental and standard materials were applied on Apr 8 on mature Glohaven peaches. Trees were sprayed to runoff using a Bean 35 gal/min (32.49 liters/min) hydraulic sprayer operating at 300 psi (21.09 kg/cm2). Single tree plots were arranged in a randomized block design and replicated four times. Buds were in the late pink stage of development at the time treatments were applied. Treatment effects were evaluated on Apr 30 by counting the number of aphid colonies per tree. Treatments were reapplied on May 4 and two additional treatments were added. Evaluations on May 12 were made by counting the numbers of colonies per tree and by checking each colony for live aphids thus evaluating the effectiveness of the second application on existing aphid colonies. In addition to the insecticides being evaluated, other spray materials used include carbamate (Fermate), azinphosmethyl (Guthion) and captan.

The treatment area was divided into 2 blocks, A and B, consisting of spur and Top Red Delicious trees, respectively. The trees were 5-6 years old and .of uniform size. Various insecticide and miticide treatments were applied prior to the start of the aphid tests. These were: March 17 - Cyprex (1.12 kg/ha, Block A) and superior oil (37.415 litre/ha + Cyprex 1.12 kg/ha, Block B); March 25, 30 - Dikar (2.80 kg/ha, Block A) and superior oil (2.34 litres/ha + Benlate .28 kg/ha, Block B); April 6, 13 - Dikar (2.80 kg/ha, Block A) and superior oil (2.34 litres/ha + Benlate .28 kg/ha + Polyram 1.40 kg/ha, Block B). On April 20, the two blocks were put on different spray programs: Block A - Dikar (2.80 kg/ha + Zolone 1.12 kg/ha); Block B - Benlate (.28 kg/ha + Guthion .28 kg/ha). These materials were applied on April 20, 27 and on May 5, 12, 19 and 26. A pretreatment count of terminals infested with A. pomi was made on May 27. This was done by randomly selecting 200 branches per block; the terminal 20 cm of each branch was checked for apterous aphids; 80% infested in both blocks. Many predators were observed and recorded. Among these were: Deraceocorisnebulosus Uhler, Oriusinsidiosus Say, Stethoruspunctum LeConte, Leptothripsmali (Fitch), Leucopis sp., many species in the Syrphidae and Chrysopidae and a number of spiders. On May 28, the following materials were applied to different treatment plots in each block: Pirimor 50W (0.70 kg/ha), Pirimor 50W (0.35 kg/ha), Cygon 43.5EC (0.12 litres/ha), Cygon 43.5EC (0.06 litres/ha), Phosphamidon 8EC (0.60 litres/ha). The plots consisted of 6 trees each, with 6 plots in the same row. Treatment rows were spaced with a buffer row between them. Each treatment was replicated 4 times, twice in each block.

The recommended rates of each pesticide were mixed with water in 1L containers in the laboratory. Styrofoam cups (270 ml) containing apple cuttings with all but 4 leaves removed were dipped in each mixture. Larvae in the fourth and fifth instar were immediately added to the cups. Each treat-ment was replicated 4 times with 10 larvae per cup. Mortality readings were taken at 24 h. intergals for 5 days. Larvae were considered dead only when they did not move when poked with a probe.

Seven treatments of Lannate-L plus a water control were used to assess the material’s effect on eggs of several pest insects and mites. The treatment rates ((litre (ounces) of Lannate 1.8 L/378. 5 litres (100 gallons) water)) applied to eggs of L.pomonella, P.ulmi, and Platynota spp. were: 0.95 (32); 0.83 (28); 0.71 (24); 0.59 (20); 0.47 (16); 0.35 (12); 0.24 (8); water control. For A.velutinana the treatment rates ((litre (ounces) of Lannate 1.8 L/378. 5 litre (100 gallons) water)) were: 0.95(32); 0.47(16); 0.24 (8); 0.12 (4); 0.06 (2) water control.

Four apple trees (one of each of the four cultivars, Triple Red Delicious, Yellow Delicious, Double Red Stayman and Commander Red York) were sprayed to the drip point for each treatment and the water control. All treatment trees were bordered on all sides by unsprayed buffer trees. Application was with an adjustable hand gun at 200 psi (14 kg/cm2). The pH of spray water was 7.4 in all cases. Treatments were applied on Apr 18, 24, May I, 12, 22, 28; Jun 4, II, 18, 25, Jul 2, 9, 16, 24; Aug 6 and 13. Pounce 3.2EC, 4 oz/100 gal (.31ml/litre) was applied up to and including Jun 4 on one treatment (4 trees). Commencing on Jun II at the manufacturer’s request, F.M.C. 45806 2.5ECat 2 oz/100 gal (l.56ml/litre) was substituted for Pounce. In determining the percent fruit injured by codling moth and plum curculio injuries per 50 fruit, from each of the four replicates, for each treatment were recorded if there were 50 apples present. Where there were less than 50 fruit, all were counted and the percentage injured recorded.

Each pesticide, or pesticide combination, was applied to two rows of 6 year old apple trees on as close to a weekly schedule as possible. Application was with a Swanson air blast sprayer calibrated to deliver 25 gpa (233.55 liters/ha) from each side, at 2 mph (3.22km/hr) and 100 pst (7.02kg/cm2) pump pressure. Sides of the trees sprayed were alternated on each successive spray date after bloom (May 22 and thereafter). Each treatment and the control contained four trees (16 total) of each of the cultivars Triple Red Delicious, Yellow Delicious, Commander Red York and Double Red Stayman. All plots were sprayed (one side only) on Apr 8, 25, May 12, 22, 28, Jun 4, II, 18, 25, Jul 2, 9, 16, 24, 30, Aug 6, 13. Fruit yield was much reduced by two severe frosts of 26°F (-3.34°C) and 24°F (-4.45°C) during bloom. This reduced the reliability of fruit injury data since the same fruit was counted on successive sample dates out of necessity. Effectiveness of the materials was evaluated against several pests as follows: fruit damage was evaluated by counting injuries per 50 apples (where possible) on each of four trees of each of four cultivars. For analysis data from each cultivar were combined. Terminal injury by apple aphids was recorded as number infested out of ten terminals per tree for 16 trees per treatment (four trees of each of four cultivars). Mites and mite eggs were sampled by collecting 20 leaves per tree from each of 4 trees of each of 4 cultivars, brushed onto glass plates and counted with a binocular microscope following the Henderson-McBurnie method. Data were recorded as mites or mite eggs per leaf.

Foliar copper deposits varied by a factor of 5-fold when copper was applied with an airblast sprayer at a rate of 935 liters/ha (100 gallons/acre) to trees of apple (Malus domestica Borkh.). Higher deposits were recorded as tree size decreased. Chemical deposit was related inversely to percentage of light penetration through the canopy.

Experimental insecticide treatments were applied in a comparative test to mature semi-dwarf Golden Delicious trees on May 13, May 27, Jun 11, Jun 25, Jul 9, Jul 23, Aug 11 and Sep 2-3. Treatments were applied with a Bean 35 gal/mln (132.49 litres/min) hydraulic sprayer operating at 300 psi (21.09 Kg/cm ). Single tree treatments were replicated four times in a randomized block design. Trees were sprayed to run-off. Mites were counted on 25 leaves from each tree using a modified Henderson-McBurnie leaf brushing technique. In the Aug 5 evaluation, twospotted spider mites were recorded separately. Counts of S. punctum adults and larva, Chrysopa spp. larva, O. insidiosus, L. mali and spiders were made on Aug 7 and Aug 14. Five limbs on each tree were tapped over a one square meter sheet of white cloth by striking each limb 5 times with a rod. Predators dislodged onto the sheet were recorded. Significant differences (P = .01) were observed between treatment means for all predators except L. mali and spiders. The Aug 7 count indicates the seasonal buildup of these predators after 6 pesticide applications. The Aug 14 evaluation more accurately represents the immediate effects of the Aug 11 application of the test materials. These data must be considered in conjunction with the mite data since in some cases (particularly the DPX-3792 treatment) mite populations were controlled and therefore predator populations never materialized. Rosey apple aphid damage was evaluated on Aug 13 by counting all damaged fruit clusters that could be found in a two minute search on the tree from the trunk to the outer perimeter of the canopy and to a height of 10 feet above the ground. A damaged fruit cluster consisted of 1 or more apples on a fruiting spur which had been damaged by rosy apple aphid feeding. Fruit was harvested (100 apples/rep; 400/treatment) and evaluated in mid-Oct for the leafroller complex (VL, TABM, RBLR), codling moth, curculion, scale and tarnished plant bug. Of these pests, only the leafroller complex was present in sufficient numbers to show significant differences (P = .01) between treatment means. Samples were evaluated for finish differences on a scale of 0 to 6 (0 = no russet, 6 = severe russet). Fruit size and weight measurements were recorded but no significant differences were found (P = .01) between treatment means or treatments and check.