SURVIVAL OF APPLE MAGGOT LARVAE, RHAGOLETIS POMONELLA (DIPTERA: TEPHRITIDAE), IN PICKED AND UNPICKED APPLES

Apple maggot eggs, Rhagoletis pomonella (Walsh), hatched equally well in apples on the tree and in picked fruit. Many larvae completed development in all different maturities of picked fruit and development and survival were similar in different cultivars. In contrast, larval mortality was high in apples remaining on the tree, particularly in fruit infested in late June and July. More larvae survived in the unpicked fruit of the earlier ripening, softer cultivars, Wealthy and McIntosh, than in the later ripening Rhode Island Greening and Rome apple

CAPTURE OF RELEASED APPLE MAGGOT FLIES, RHAGOLETIS POMONELLA (DIPTERA: TEPHRITIDAE), ON STICKY PANELS

In 1975, 19.4% of 6950 marked apple maggot adults, Rhagoletis pomonella, which were released in the center of a 7 × 7 array of unsprayed apple trees were recaptured on Pherocon® AM traps. The distribution of the marked flies was not uniform as most of the flies were recaptured near the release point. The distribution of native flies which migrated into the test area from adjacent infested apple trees was also non-unifor

RESPONSE OF THE APPLE MAGGOT, RHAGOLETIS POMONELLA, AND THE CHERRY FRUIT FLY, R. FAUSTA (DIPTERA: TEPHRITIDAE), TO PROTEIN HYDROLYSATE BAIT SPRAYS

None of five mixtures of protein hydrolysate and azinphosmethyl which were applied as foliar sprays (1.0, 2.0, 5.0% yeast hydrolysate, 2.0% corn hydrolysate, and 2.0% soy hydrolysate) killed significantly more apple maggot flies, Rhagoletis pomonella, or black cherry fruit flies, R. fausta, than a spray of azinphosmethyl alone which was used as a control. This suggests that hydrolysate bait sprays would be no more effective than a toxicant alone in controlling these flie

Effects of Field Applied Residues and Length of Exposure to Tebufenozide on the Obliquebanded Leafroller (Lepidoptera: Tortricidae)

Studies were conducted with the obliquebanded leafroller, Choristoneura rosaceana (Harris), and tebufenozide to determine the influence of various factors on the efficacy of this insecticide under field conditions. Larvae were exposed to apple foliage collected from commercial orchards at different intervals after insecticide applications. Mortality of neonates on actively growing (terminal) and mature (spur) foliage 10 d after an airblast sprayer application of tebufenozide was 0 and 35-74%, respectively. Feeding by larvae was also assessed on collected foliage. There was significantly less feeding on tebufenozide-treated foliage than chlorpyrifos- and nontreated foliage (P 90%. In the third study, to examine the effects of obliquebanded leafroller movement to foliage with sublethal residues, we designed a laboratory bioassay in which larvae were exposed to foliage treated with tebufenozide and transferred to untreated foliage after various exposure intervals. The higher the concentration of tebufenozide, the less exposure time was necessary to cause high levels of mortality of neonates. The terminal feeding behavior of obliquebanded leafroller larvae, low residues on terminal foliage before the end of the typical 2-wk spray interval, and the length of exposure necessary for high levels of mortality may decrease the effectiveness of tebufenozide for obliquebanded leafroller contro

PHENOLOGY OF THE SAN JOSE SCALE (HOMOPTERA: DIASPIDIDAE) IN NEW YORK STATE APPLE ORCHARDS

Pheromone trapping studies from 1979 to 1981 showed that there were two periods of San Jose scale, Quadraspidiotus perniciosus (Comstock), male flight activity annually in western New York apple orchards. Spring flight, which resulted from overwintering black caps, began at ca. 94-140 degree-days (base 10 °C from 1 March) and occurred during bloom in the apple varieties studied. First generation crawlers emerged at ca. 360 degree-days. Second generation crawlers emerged at ca. 890 degree-days and were active throughout September. Regression analyses showed a logistic relationship between crawler density and fruit infestation, and inverse linear relationships between pheromone trap catches and San Jose scale infestation levels within tree

APPLE MAGGOT (DIPTERA: TEPHRITIDAE) MONITORING IN AN APPLE PEST MANAGEMENT PROGRAM

Traps were used to monitor the emergence and seasonal activity of apple maggot flies, Rhagoletis pomonella (Walsh), in unsprayed habitats, and in selected commercial blocks and farms in the New York apple pest management program to determine the need and timing of control sprays. An average of 69, 43, and 43% fewer sprays and 71, 47, and 57% less insecticides were applied for apple maggot control, respectively, in single blocks monitored in 1976, 1977, and farms monitored in 1977, than in representative orchards in the same areas using regular commercial control schedule

Airborne Dispersal of San Jose Scale, Quadraspidiotus perniciosus (Comstock) (Homoptera: Diaspididae), Crawlers Infesting Apple

The aerial dispersal of San Jose scale, Quadraspidiotus perniciosus (Comstock), crawlers within the apple tree canopy and between trees was positively correlated with the seasonal abundance of crawlers on the bark. Airborne crawlers were significantly more abundant within the upper portions of the canopy and in the northeast and southeast quadrants. These data supported observations on variations in crawler density by location on the host and suggested that wind direction may have affected the distribution of crawlers dispersing aerially within the trees. The magnitude of aerial dispersal between trees was related to the levels of airborne dispersal within the canopy and the distance to the infested sourc

INFLUENCE OF APPLE CULTIVAR, TREE PHENOLOGY, AND LEAF QUALITY ON THE DEVELOPMENT AND MORTALITY OF CHORISTONEURA ROSACEANA (LEPIDOPTERA: TORTRICIDAE)

The obliquebanded leafroller, Choristoneura rosaceana (Harris), is a polyphagous insect that is occasionally a serious pest of apple trees. To determine how well adapted it is to this host plant, we studied its nutritional ecology by measuring the development and mortality of larvae and pupae reared on different sets of leaves. We investigated the influence of 3 apple cultivars, 2 time periods (June, July-August), and several leaf types, including those with different ages and different branch positions, on these processes. Larvae and pupae developed more rapidly with lower mortality on younger leaves than on older ones. When larvae were fed leaves collected from the same cultivar and branch position at different times during the season, developmental rates were faster and survival rates were higher earlier in the season. Development and survival were similar on leaves of all cultivar

Oviposition Model for Timing Insecticide Sprays Against Plum Curculio (Coleoptera: Curculionidae) in New York State

Plum curculio, Conotrachelus nenuphar (Herbst), feeding and oviposition on apples during spring was measured for 3 yr in a heavily infested orchard in New York State. A logistic model was formulated to relate cumulative fruit injury to cumulative heat units (degree-days base 10°C [DD10]) following petal fall. Cumulative plum curculio injury was well described by the model in the trees from which data for the model were collected. However, injury progressed faster and ended earlier in smaller trees at the same site and at a different site, probably because of differences in tree architecture. Field trials showed that protection of the fruit via insecticide residue was no longer necessary after the model predicted that 40% of the cumulative plum curculio oviposition and feeding cycle had been completed (171 DD10 after petal fall). Based on historical weather records, use of the model to schedule insecticide treatments would save 1 insecticide application nearly half the time compared with a standard of 3 insecticide applications. A delay between initial plum curculio feeding and oviposition, which coincides with the petal fall, phenophase, and steadily increasing damage, which is influenced by temperatures after petal fall was observed. The effectiveness of delaying insecticide treatments until the rate of plum curculio damage was rapidly increasing was compared with treatments applied at petal fall. Delaying the 1st insecticide application resulted in higher levels of damage compared with making the 1st treatment immediately after petal fal

Assays with Commercially Produced Trichogramma (Hymenoptera: Trichogrammatidae) To Determine Suitability for Obliquebanded Leafroller (Lepidoptera: Tortricidae) Control

Laboratory assays were used to compare the ability of commercially produced Trichogramma spp. to parasitize eggs of the obliquebanded leafroller, Choristoneura rosaceana (Harris), in the laboratory and field. Trichogramma platneri Nagarkatti parasitized more obliquebanded leafroller eggs per egg mass than did Trichogramma pretiosum Riley or Trichogramma minutum Riley produced by either of 2 insectaries. T. minutum produced at 1 insectary caused significantly more host mortality by host feeding and repiercing than by parasitism. Variation in parasitoid performance from different insectaries and among shipments from the same insectary was common. Young egg masses were more heavily parasitized than old egg masses. Parasitism increased as the number of conspecific female Trichogramma spp. placed on the same host increased, but the number of eggs parasitized per female decreased. Exposure of host egg masses to female Trichogramma spp. prevented additional oviposition in the same egg mass by conspecific, ovipositionally experienced females but had no effect on parasitism by conspecific, ovipositionally naive females. The method used to attach sentinel egg masses to foliage influenced parasitism rates. Moistening the leaf with water and adhering the egg mass to the moistened leaf had the least impact. Inundative releases of Trichogramma spp. into an apple orchard paralleled laboratory assays by showing greater parasitism of obliquebanded leafroller egg masses by T. platneri than with T. minutum. However, extreme differences observed in field performance between the 2 species was not predicted from the assay