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Clifford S. Sadof, Robert J. O'Neil, Farah M. Heraux, and Robert N. Wiedenmann

More than 500 Master Gardeners in Indiana and Illinois were taught alternatives to the use of insecticides in workshops that focused on biological control of insect pests in home gardens. Gardeners also learned to conduct experiments in their backyards and were encouraged to participate in a summer research program that tested specific control methods. Workshop participants were surveyed before the workshop, and in two successive growing seasons to measure changes in their pest management practices. Overall, a significant percentage of gardeners stopped applying insecticides for up to two consecutive growing seasons after attending workshops. In addition, the adoption of biological control by participants appeared to be linked to their insecticide use and willingness to participate in the research process. A significant increase in the adoption of biological control was noted among garden researchers who did not use insecticides before the workshop or had reduced insecticide use following the workshop. No such change was noted for gardeners that did not conduct research. The relative contributions of workshop participation and hands-on research experience in pesticide reduction and biological control adoption are discussed.

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Joyce G. Latimer and Ronald D. Oetting

Four-week-old salvia (Salvia splendens F. Sellow `Red Pillar') seedlings were treated with 0 or 50 ppm paclobutrazol, followed 5 h later by 0, 1, 2, or 4 times (0×, 1×, 2×, or 4×, respectively) the recommended label rate of bendiocarb (0.6 g a.i./liter), a carbamate insecticide. Seven days after treatment (DAT), phytotoxicity ratings increased with bendiocarb rate on all plants, but 50 ppm paclobutrazol reduced damage at 1× and 4× bendiocarb. Paclobutrazol also improved plant recovery from phytotoxicity damage at 21 DAT. Bendiocarb decreased the height of plants not treated with paclobutrazol at 7, 14, and 21 DAT. Plants treated with 40 ppm paclobutrazol had lower maximum phytotoxicity damage at 14 DAT, and even better recovery at 21 DAT than plants treated with 20 or 60 ppm paclobutrazol. Plants treated with paclobutrazol 4 days before applying bendiocarb had lower maximum phytotoxicity ratings relative to controls than plants treated 8 days before, the same day as, or 4 days after bendiocarb application. Chemical names used: β- [(4-chlorophenyl)methyl]- α -(1,1-dimethylethyl)-1 H- 1,2,4-triazole-1-ethanol (paclobutrazol); 2,2-dimethyl,1,3-benzodioxol-4-yl-methylcarbamate (bendiocarb).

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Larry J. Gut, Peter H. McGhee, and Ron Perry

The relationship between the extent of burrknots on apple rootstocks and dogwood borer (DWB) [Synanthedon scitula Harris] infestation, and the efficacy of a cultural management strategy for this pest were studied in heavily infested plots at the Michigan State University Clarksville Horticulture Experiment Station. Spearman rank correlation Rho values of 0.85 and 0.75 in consecutive years of the study substantiated a strong positive correlation between the number of larvae present in the rootstock and the surface area of the rootstock covered by burrknots. Cultivar type affected the level of the DWB infestation in the rootstock. Larval densities were 8- to 10-times higher in Mark rootstocks when the grafted scion was `Idared' instead of `Liberty'. This cultivar related difference in larval infestation was associated with a greater number of burrknots on `Idared'/Mark compared to `Liberty'/Mark trees. Mounding of soil to cover the exposed rootstock was found to be a highly effective alternative to insecticides for DWB control. Under conditions of heavy pest pressure, this cultural control tactic provided 76% to 99% reductions in larval densities. These levels of control are comparable to or better than those reported for trunk sprays with chlorpyrifos, the most effective of currently available insecticides.

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Cynthia L. Barden and Larry A. Hull

`Golden Delicious', `Delicious', and `York Imperial' apples (Malus ×domestica Borkh.) with various amounts of tufted apple bud moth (TABM) [Platynota idaeusalis (Walker)] feeding injury were evaluated for quality at harvest and following storage in air and controlled atmosphere. In addition, apples were artificially injured during two seasons to mimic TABM feeding injury. There was little or no effect of natural TABM injury on the quality of apples in many experiments. At harvest, firmness was not influenced by natural TABM injury, soluble solids concentration (SSC) was increased in three of 11 experiments, and starch levels decreased in two of 11 experiments. These results indicate a slight advancement of maturity of injured fruit. More severely injured fruit tended to have more decay after storage than fruit with less injury. Some injury, especially first brood injury, up to ≈7 to 10 mm2 surface damage, can be tolerated without compromising storage quality of processing apples. However, severe injury (>79 mm2) can increase decay. Second brood injury, whether caused by natural feeding of TABM or through artificial means, usually caused a higher incidence of decay than first brood injury. Artificial injury imposed close to harvest led to more decay in storage than did similar injury imposed earlier.

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David G. Hall, Tim R. Gottwald, Ed Stover, and G. Andrew C. Beattie

materials effective against ACP and sequenced to reduce development of resistant insects (the “complete” insecticide program); 2) citrus interplanted with orange jasmine with citrus subjected to a reduced insecticide program and orange jasmine not treated

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David A. Bender and William P. Morrison

Indian mustard trap crops have successfully reduced pesticide use on commercial cabbage in India. Diamondback moth has been a serious pest of cabbage in Texas and has demonstrated resistance to most classes of insecticides. Use of a trap crop could fit well in an integrated management program for cabbage insects, Three-row plots of spring and fall cabbage were surrounded by successive single-row plantings of Indian mustard in trials at Lubbock, Texas to determine the efficacy of interplanting for reducing insecticide applications. Insects in the cabbage and Indian mustard were counted twice weekly, and insecticides were applied selectively when economic thresholds were reached. Indian mustard was highly attractive to harlequin bugs, and protected intercropped spring cabbage. Cabbage plots without mustard required two insecticide applications to control the infestation. False chinch bugs were also highly attracted to Indian mustard. Lepidopterous larvae, including diamondback moth, did not appear to be attracted to the trap crop. Indian mustard trap crops reduced insecticide applications to spring cabbage but had no positive effect on fail cabbage.

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David A. Bender and William P. Morrison

Indian mustard (Brassica juncea) has been reported to be a preferred host for diamondhack moth (Plutella xylostellu) and other insect pests when interplanted with cabbage (Brasssica oleracea var. capitata). A cabbage-Indian mustard companion planting study was conducted to determine the seasonal occurrence of cabbage insects and the potential for using a trap-crop system to reduce insecticide applications to cabbage in West Texas. Three-row plots of cabbage 9 m long were transplanted with and without sequentially seeded borders of Indian mustard in three seasons. Harmful and beneficial insects were counted at roughly weekly intervals. Insecticides were applied when insect populations in individual plots reached predetermined thresholds. Indian mustard did not appear to be more attractive than cabbage to lepidopterous pests, but did preferentially attract hemipterans, particularly harlequin bugs (Margantia histrionica). The mustard trap crop eliminated two insecticide` applications in one trial by reducing harlequin bug pressure on the cabbage.

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Raymond A. Cloyd and Clifford S. Sadof

A 2-year greenhouse study was conducted to evaluate the seasonal population dynamics and use of an action threshold for western fl ower thrips (Frankliniella occidentalis) in cut carnation (Dianthus caryophyllus). An action threshold of 20 thrips/card/week was adopted to time insecticide applications. The highest numbers of thrips were caught on blue-colored sticky cards from May through September whereas the lowest thrips numbers were present from November through March 1994 and 1995. Thrips numbers based on sticky card counts, from December through March for both years were below the action threshold and as a result, no insecticides were applied. Thrips abundance on blue sticky cards was significantly correlated with both numbers of thrips in fl owers and a subjective ranking of fl ower quality. Seasonal patterns of both insecticide use and numbers of damaged fl ow- ers closely followed patterns of thrips abundance found on blue sticky cards. Our findings are the first to demonstrate, based on a case study over a 2-year period, that routinely scouting for thrips throughout the year can lead to fewer insecticide applications and thus possible cost savings in labor and insecticide purchases. This study suggests that sticky cards can be an effective tool for reducing insecticide applications in regions of the U.S. where there are seasonal fl uctuations of thrips abundance.

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Daniel F. Warnock and David W. Davis

European corn borer, Ostrinia nubilalis Hübner, is an economic pest of sweet corn. Consumer demand for high-quality, insect-free produce with minimal pesticide residue necessitates exploitation of various control options. Ear feeding resistance could reduce insecticide inputs. The inheritance of ear feeding resistance and silk channel length in the F1 derived from a diallel cross (Griffing's model I, method 2) of eight breeding stocks describing a wide range of feeding resistance was investigated in field experiments. Feeding damage, based on a 1 (no damage) to 9 (>10% ear damage) visual rating scale, and silk channel length of ears that had been manually infested at the ear tip with O. nubilalis were recorded. A significant (P ≤ 0.05) year by location interaction was found for ear feeding damage and silk channel length. Genotype ear feeding damage and silk channel length differences were significant (P ≤ 0.01) beyond genotype by environment (year and location) interactions. Mean feeding damage ranged from 2.5 (parents 1 × 7) to 8.8 (parent 2) and mean silk channel length ranged from 1.9 cm (parents 2 × 7) to 9.0 cm (parent 3). Ten of the 28 possible crosses (reciprocals combined) and 1 parent were classed as resistant (damage rating < 3.0). Eleven crosses, including all 7 involving parent 2, and 2 parents were susceptible (damage rating > 4.0). Pearson's correlation analysis indicated lower damage levels were weakly to moderately associated with increased silk channel length for both parents (r = –0.18) and progeny (r = –0.44). The general combining ability (GCA) component was significant (P ≤ 0.01) for ear feeding damage, suggesting additive effects control ear feeding damage. GCA and specific combining ability (SCA) effects did not account for silk channel length variability, suggesting strong environmental influences. Improved ear feeding resistance should be possible via recurrent selection with recombination.

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Joe R. Williamson and Donn T. Johnson

Agricultural monocultures with intensive pest management practices reduce diversity and create instability in agricultural ecosystems, thereby increasing reliance upon pesticides. This study compares the influence of three insect pest management programs in vineyards on arthropod diversity as well as parasitism and control of grape berry moth (Endopiza viteana), the key pest of grapes (Vitis labrusca) in eastern North America. Vineyards in Bald Knob, Hindsville, Judsonia, Lowell, and Searcy, Ark., were managed with a range of intensity of insecticide use, a reduced insecticide program with Exosex-GBM dispensers for mating disruption, or no pesticide use in abandoned vineyards. Arthropod diversity and carabid (Carabidae) density in each vineyard was sampled with pitfall traps. Grape berry moth flight was monitored by pheromone traps. Grape berry moth–infested grapes were collected from the field and reared in the lab until parasites or moths emerged. There were significant differences in arthropod diversity between vineyard sites, with Shannon diversity index values generally higher in woods and managed vineyards with conventional sprays and/or mating disruption than in abandoned sites. Shannon index values for arthropod diversity were significantly lower at the vineyard edge in Searcy (recently abandoned), vineyard center and edge in Bald Knob (abandoned), and the vineyard edge in Hindsville (conventional sprays). In 2003, carabid density was significantly highest in the edge and center of the Hindsville vineyard (high insecticide usage) and the abandoned Bald Knob vineyard had significantly lowest carabid density. Apparently, insecticide sprays resulted in more food on the vineyard floor for carabids. The vineyard floor management was too variable among vineyards to deduce its effect on carabid density. With some exceptions, low-spray and no-spray vineyards generally showed greater diversity and parasitism of grape berry moth than high-spray vineyards. Parasitism was higher in some high-spray vineyards than in low-spray with mating disruption vineyards. Grape berry moth flight and berry damage were more dependent on spray timing than intensity. This study demonstrates that insect pest management programs impact arthropod diversity and parasitism. Further testing is needed to determine why parasitism of grape berry moth decreased in the vineyards using the mating disruption tactic.