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

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

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

Edge Effects in the Directionally Biased Distribution of Choristoneura rosaceana (Lepidoptera: Tortricidae) in Apple Orchards

Edge effect tests have been used in a number of studies on obliquebanded leafroller, Choristoneura rosaceana (Harris), to test for evidence of mated female immigration into pheromone-treated orchards. This type of test compares obliquebanded leafroller presence or activity around the perimeter of an orchard against presence or activity in the interior. Higher numbers detected around the edges of an orchard would indicate higher levels of flight activity at the edge, a pattern that could be generated by high levels of immigration. Recent work has shown that the spatial distribution of recaptured obliquebanded leafroller adults released from a single location can be directionally biased, which could obscure the ability to detect an edge effect. To test this theory, data from an orchard study conducted in 1991 that found no significant edge effect was reanalyzed. When we accounted for the directional bias in the distribution of first-generation mated female moths, we found an edge effect with significantly more mated females captured in the edge traps than in the center or mid-interior traps. No edge effect was found when the directional bias was ignored. In addition, second-generation males and mated females both showed a significant edge effect that had not been detected in the original analysis, which had combined both first- and second-generation dat

Getting the User’s Attention

CAN WE DELIVER INFORMATION the way our users want it--cheap, fast, and good? According to Stewart Bodner, associate chief librarian of the New York Public Library, that\u27s what users desire and what librarians and vendors must provide. But at least in the public library world, convenience trumps quality every time, Bodner went on to tell the audience at the annual meeting of NFAIS (National Federation of Abstracting and Information Services) in Philadelphia this February. NFAIS brought together company representatives and librarians to brainstorm ways to redirect users away from Internet search engines and the open web and toward high-quality information

The [4+2]‐Cycloaddition of α‐Nitrosoalkenes with Thiochalcones as a Prototype of Periselective Hetero‐Diels–Alder Reactions—Experimental and Computational Studies

The [4+2]‐cycloadditions of α‐nitrosoalkenes with thiochalcones occur with high selectivity at the thioketone moiety of the dienophile providing styryl‐substituted 4H‐1,5,2‐oxathiazines in moderate to good yields. Of the eight conceivable hetero‐Diels–Alder adducts only this isomer was observed, thus a prototype of a highly periselective and regioselective cycloaddition has been identified. Analysis of crude product mixtures revealed that the α‐nitrosoalkene also adds competitively to the thioketone moiety of the thiochalcone dimer affording bis‐heterocyclic [4+2]‐cycloadducts. The experiments are supported by high‐level DFT calculations that were also extended to related hetero‐Diels–Alder reactions of other nitroso compounds and thioketones. These calculations reveal that the title cycloadditions are kinetically controlled processes confirming the role of thioketones as superdienophiles. The computational study was also applied to the experimentally studied thiochalcone dimerization, and showed that the 1,2‐dithiin and 2H‐thiopyran isomers are in equilibrium with the monomer. Again, the DFT calculations indicate kinetic control of this process