ABSTRACT The plum curculio, Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae), is an important pest of fruit in North America. Males produce an aggregation pheromone (grandisoic acid) that attracts both sexes of the northern univoltine and the southern multivoltine strains. Grandisoic acid ((1R,2S)-1-methyl-2-(1-methylethenyl)-cyclobutaneacetic acid) is a chiral molecule containing one chiral center. A synthetic racemic mixture will contain two optical isomers that are mirror images of each other with equal amounts of (+)- and (-)-enantiomeric isomers. Male plum curculio only produce the (+) enantiomer. Some enantiomers can have antagonistic effects on the attraction of weevils to pheromones. An understanding of the effect of both enantiomers on the behaviour of plum curculio is needed to develop more efficient trap baits. Behavioural bioassays were conducted in a dual-choice still-air vertical olfactometer using a quantity of 1.5 ml of both (+) and (-) synthetic enantiomers and the racemic mixture of grandisoic acid with live female responders to determine which concentration and enantiomeric purity is the most attractive and if there is an antagonistic effect of the unnatural (-) enantiomer. Results indicated that plum curculio were attracted to low concentrations of the (+) enantiomer at 72% enantiomeric excess, but that strains were attracted to different concentrations of the (+) enantiomer (2×10-7 mg/ml for univoltine, 2×10-9 mg/ml for multivoltine).

The plum curculio (PC), Conotrachelus nenuphar Herbst (Coleoptera: Curculionidae), is a key pest of stone and pome fruit in North America. Though grandisoic acid (GA) was identified as a male-produced aggregation pheromone for this species, other components likely exist, as have been identified for various curculionids. To better determine these components, an understanding of the conditions necessary for optimum pheromone production and attraction is needed, this is essential for the improvement of monitoring techniques and to achieve better biological control. The goal of this study was to determine the biotic and abiotic factors influencing both the response to pheromones and pheromone production. Tests were conducted in a dual-choice still-air vertical olfactometer using live male PCs as odour sources and live females as responders, to determine which physiological factors (age, number of males, mating status) influenced female response to males. Head-space collections of GA production under various conditions (airflow rate and frequency, collection zone strata, variation of humidity, temperature, and presence of a harbourage) were also done, as were electroantennograms (EAG) using synthetic pheromone mixtures. Results revealed that for both strains, the odour of two virgin mature males elicited significantly greater and more consistent attraction from mature virgin females than other ages and numbers of males when compared with the control. Head-space collections indicate that male PC have increased production of GA under high humidity in the presence of fruit, indicating that these conditions are necessary for optimal pheromone production and collection. EAG studies revealed significant responses to GrandLures I, II, III/IV and to the positive enantiomer of GA, and the amplitude of the signal varied with concentration. Our data identify the optimal physiological state and conditions at which pheromone collections should be performed, and what physiological life stages respond to these stimuli. These results have implications for optimising monitoring tools for this serious crop pest. This species has a northern univoltine strain and a southern multivoltine strain, both of which were examined in this study.

The effect of a pheromone antagonist-based disruption blend on disruption of dogwood borer, Synanthedon scitula (Harris), mate-finding behavior and incidence of infestation was evaluated in a commercial apple orchard from 2006 - 2008. Although the pheromone antagonist based disruption blend treatment significantly disrupted-male-mate-finding behavior during-each year of the study, there was a significant increase in the percentage of infested trees from the start to the conclusion of the experiment, likely due to the immigration of mated females from surrounding untreated orchard blocks. In 2007, pheromone-baited traps deployed in an east west transect through the study area showed that capture of male moths increased as the distance from the disruption plot increased. The results of geostatistical analysis indicated that there were high degrees of aggregation in dogwood borer infestations in the study area, with ranges of spatial autocorrelation from 10.2 - 22.5 m. For each year, the spatial distribution of larval infestation was best described by the exponential semiovariogram model. Interpolated surface maps revealed areas of high infestation levels, which were more prevalent within the control 2 plot in 2006 and 2007. Infestation sites increased in size and intensity each year of the study in the disruption and control 1 plot.

The plum curculio, Conotrachelus nenuphar, is a major pest of stone and pome fruit (e.g., apples, pears, peaches, cherries, etc.). Entomopathogenic nematodes (Steinernema spp. and Heterorhabditis spp.) are virulent to ground-dwelling stages of C. nenuphar and may be incorporated into an integrated management strategy. Two significant questions that must be addressed prior to implementation are: (1) which nematode is most effective in suppressing the target pest under field conditions? and (2) what is the impact of various irrigation levels on field efficacy? We addressed these questions by comparing the efficacy of two nematodes, Steinernema riobrave and Steinernema feltiae (two nematodes that showed the highest virulence in prior lab assays and field trials) and an untreated control, at three irrigation levels 0, 1 and 6 irrigation events applied during a two-week period post-application. C. nenuphar larvae were added to mini-plots prior to treatment application. Treatment effects were assessed by comparing the number of C. nenuphar adults emerging from each plot. The experiments were conducted at two field sites (apple orchards in Kearneysville, West Virginia and Belchertown, Massachusetts) in 2011 and 2012. Relative to the untreated check, S. riobrave caused 85.0% and 97.3% control in 2011 and 2012 in Massachusetts (respectively) and 100% control in West Virginia both years, whereas S. feltiae caused 0% and 84.6% control in 2011 and 2012 (respectively) in Massachusetts, and 78.2% and 69.7% control in West Virginia. The level of C. nenuphar suppression caused by S. riobrave was higher than suppression by S. feltiae at both sites in 2011 (no differences were detected in 2012). Irrigation did not have a significant effect on C. nenuphar suppression at both sites and in both years of the experiments. The lack of irrigation effects is an unusual finding for field applications using entomopathogenic nematodes, and may have been due to the level of precipitation and water-holding capacity in the field soils tested. The results of this study have positive implications for the potential of incorporating entomopathogenic nematodes into a C. nenuphar management program. Published by Elsevier Inc.

Twenty eight insecticides were evaluated in the laboratory to characterize the impact of specific compounds on locomotory behavior and mobility of adult Halyomorpha halys (Stål) (Hemiptera: Pentatomidae). Horizontal distance and angular velocity were measured for individuals exposed to dry insecticide residue for 4.5 h to evaluate how quickly and intensely a given insecticide induced changes in motor activities in no-choice glass arenas. Eight out of nine pyrethroid insecticides induced uncoordinated and irregular movement within 10 min after exposure to insecticides. After 1.5 h, most adults were incapacitated. By contrast, there was no immediate stimulation when H. halys were exposed to organophosphate residues. After 1.5 h, four out of seven organophosphates resulted in increased horizontal distance moved and angular velocity indicating irregular walking paths by exposed adults. Carbamate and neonicotinoid insecticides produced fairly similar patterns with virtually no stimulation in horizontal distance moved or angular velocity, except for imidacloprid and thiacloprid. Neither endosulfan (organochlorine) nor indoxacarb (oxadiazine) affected the horizontal movement of H. halys. Vertical distance climbed by adult H. halys was measured immediately after the 4.5-h insecticide exposure period and at 7 d. In general, adults that survived until day 7 were able to climb vertical distances similar to those in the control. In particular, this result was observed for seven out of nine pyrethroid materials that incapacitated all adults after the 4.5-h exposure period. Mobility changes of adult H. halys are discussed in the context of enhancing integrated pest management programs.

We evaluated the effectiveness of three cyanoacrylate glues (trade names: Krazy [Elmer's Products Inc., Westerville, OH], Loctite [Henkel Corporation, Rocky Hill, CT], and FSA [Barnes Distribution, Cleveland, OH]) to attach harmonic radar tags securely on adult Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) and quantified the effect of the radar tag attachment on insect survivorship and mobility. In the laboratory, the strength of the glue bond between the radar tag and H. halys pronotum was significantly increased when the pronotum was sanded to remove cuticular waxes. The adhesive bond of the radar tag to the sanded pronotum of H. halys had strength of 160-190-g force and there was no significant difference among the three types of glue tested. The three glues had no measurable effect on the survivorship of radar-tagged H. halys over 7 d, compared with untagged insects. Over a 7-d period in the laboratory, horizontal distance traveled, horizontal walking velocity, and vertical climbing distance were all unaffected by the presence of the tags regardless of glue. A field experiment was conducted to compare the free flight behavior of untagged and radar-tagged H. halys. Adults were released on a vertical dowel and their flights were tracked visually up to ≍200 m from the release point. There was no significant difference in take-off time or in flight distance, time, or speed between untagged and radar-tagged individuals. In addition, prevailing flight direction was not significantly different between untagged and radar-tagged individuals. The absence of measurable impact of the radar tag attachment on H. halys survivorship or mobility validates the use of harmonic radar tags to study the dispersal ecology of this insect in field conditions.

BACKGROUND An evaluation was made of the effects of seven neurotoxic insecticides (esfenvalerate, indoxacarb, clothianidin, thiacloprid, azinphosmethyl, phosmet and imidacloprid), one insect growth regulator (novaluron) and two fungicides (myclobutanin and mancozeb), with water as the control, on the horizontal mobility of plum curculios exposed to dried pesticide residues. Mobility was recorded over a 2 h period using ethological tracking software. Mortality was recorded immediately after horizontal mobility experiments and 24 h later. RESULTS Esfenvalerate had the greatest impact on mobility. Immediately after exposure to this compound, plum curculios moved significantly greater distances and for a significantly longer period of time compared with all other compounds. After 24 h, esfenvalerate also led to high mortality rates (>86.0%). Exposure to azinphosmethyl and phosmet also led to high rates of mortality, although the impact on mobility was less pronounced. Exposure to indoxacarb, thiacloprid, imidacloprid, novaluron, myclobutanin and mancozeb had no impact on mobility and resulted in little to no mortality. Clothianidin affected mobility after a 2 h exposure period, and high mortality (60%) was recorded after 24 h. CONCLUSIONS The results indicate that, in the context of a treated orchard, plum curculios exposed to dried pesticide residues may be capable of foraging before succumbing to toxicant exposure, while exposure to pesticides such as esfenvalerate may rapidly incapacitate adult plum curculios.

Trapping experiments targeting brown marmorated stink bug, Halyomorpha halys (Stal), addressed the effects of: (1) a modification to the trap container of a commercial trap, (2) the age of methyl (2E,4E,62)-decatrienoate lures, and (3) the age of dichlorvos-impregnated kill strips on bug captures. In the trap modification study, ventilation holes in the containers atop standard, commercial AgBio (TM) traps were modified to resemble a USDA prototype trap. Captures were compared among the standard traps, modified commercial traps, and prototype traps. Halyomorpha halys captures were significantly greater in the prototype trap than in standard commercial traps, whereas captures in modified commercial traps were intermediate between but not significantly different from AgBio or prototype traps. Traps baited with kill strips that were fresh or that had been field-aged for 1, 2, 3 or 4 wk showed no significant differences in the total number of H. halys captured over a 15-d trapping interval, although the percentage of dead bugs was significantly greater in traps containing fresh kill strips than in those with 3- or 4-wk-old kill strips. In the aged lure experiment, captures were not significantly different among traps baited with fresh, 1- and 2-wk-old lures or among those baited with 2-, 3- or 4-wk old lures or unbaited. Most (64.8%) bugs were captured during the first 3-d sample interval, during which traps with fresh lures captured more H. halys than those with each aged lure treatment. Weekly gravimetric measurements to determine the release of methyl (2E,4E,6Z)-decatrienoate from lures over 4 wk showed a sharp decrease in lure weight during the first 3-d interval at 20 and 25 degrees C.

Captures of the invasive brown marmorated stink bug, Halyomorpha halys (Stal), were significantly greater in pyramid traps baited with the known attractant, methyl (2E,4E,6Z)-decatrienoate, compared with unbaited traps. A dose-dependent response by adults to lures formulated with increasing amounts of methyl (2E,4E,6Z)-decatrienoate and deployed in association with black pyramid traps also was observed. Among pyramid traps representing different visual stimuli including black, green, yellow, clear, white and yellow, significantly greater captures were recorded in baited black pyramid traps for adults in 2009 and nymphs in 2010 compared with other trap types; the dark upright silhouette created by this trap likely represents a trunk-mimicking visual stimulus to foraging bugs. A ground-deployed baited black pyramid trap also captured significantly greater numbers of nymphs and adults compared with canopy-deployed commercially available baited traps from Japan. Based on semi-field cage studies, brown marmorated stink bug was confirmed to be bivoltine within the mid-Atlantic region. Thus, the need for a reliable monitoring tool to detect presence, abundance and seasonal activity of brown marmorated stink bug in tree fruit and other cropping systems is critical.

The efficacy of 37 insecticide treatments against adult Halyomorpha halys (Stal) was established based on exposure to 18-h old dry insecticide residue in laboratory bioassays. Individual adult H. halys were exposed to an insecticide residue for 4.5 h and then monitored daily for survivorship over a 7-d period. The proportion of dead and moribund insects was used as an estimate of overall insecticide efficacy against H. halys immediately after the exposure period and over the 7-d trial. Among all materials evaluated, 14 insecticides exhibited increasing efficacy, in which the percentage of dead and moribund insects (used as a measure of insecticide efficacy) increased by >10% after 7 d. By contrast, insecticide efficacy values of eight insecticides declined by >10% (based on recovery of adults from a moribund state) over the 7-d period with most belonging to the pyrethroid class. In this study, the efficacy value of neonicotinoid, acetamiprid, showed the greatest decline from 93 to 10% over 7 d. Alethality index (scale of 0-100) was developed to compare insecticides based on quantifying the immediate and longer-term effects of insecticide exposure on H. halys. Among all materials evaluated, dimethoate, malathion, bifenthrin, methidathion, endosulfan, methomyl, chlorpyrifos, acephate, fenpropathrin, and permethrin yielded the highest values (>75) because of a high degree of immediate mortality with very little recovery. Our results provide baseline information regarding potential of candidate insecticides against adult H. halys and highlight the need to consider longer-term effects in establishing overall efficacy ratings against this invasive species.

Four commercial orchards in the mid-Atlantic region of the United States were surveyed weekly in 2010 and 2011 for the presence of brown marmorated stink bug and the injury caused to both apple and peaches. Among tested sampling techniques, pyramid traps baited with the aggregation pheromone of Plautia stali Scott, methyl-(2 E ,4 E ,6 Z )-decatrienoate, yielded the most brown marmorated stink bug adults and nymphs, followed by visual observations. Brown marmorated stink bugs began to feed on apples and peaches soon after fruit set and continued to feed on fruit throughout the growing season. Injury to apple was relatively inconsequential until after mid-June, whereas feeding on peaches resulted in immediate economic injury as the surface became distorted, dented, discolored, and the flesh beneath turned brown. Significantly more apples were injured and with greater severity in 2010 than in 2011. Likewise, percent injury on the exterior portion of each apple plot was significantly greater than injury reported from the interior in both years. Growers increased the number of insecticide applications nearly 4-fold from 2010 to 2011. In addition to the increased number of targeted insecticide applications, growers also reduced the interval between treatments in 2011. A metric was created to compare the relative intensity of each grower's commercial management program between seasons and amongst each other.

The apple maggot fly, Rhagoletis pomonella (Walsh), is a key pest of apple in eastern North America that has been historically controlled with organophosphate insecticide applications. Here we report on progress toward development of an effective and maintenance-free attracticidal sphere system for this pest species. In our studies, we evaluated lethality of spinosad in combination with a feeding stimulant (sucrose) to replace a Tangletrap sticky coating as the killing agent of a sphere-based behavioral control system. Spinosad was incorporated into cylindrical and contoured controlled-release caps that were fixed atop visually stimulating sphere bases. For both cap styles, spinosad at or near 1.0% (a.i.) proved to be a relatively durable fly-killing agent, providing approximate to 85% mortality after simulated rainfall exposure reflective of average season-long precipitation levels experienced during the primary period of risk of apple maggot injury to fruit in the northeastern United States. In field trials, we assessed the impact of color degradation of contoured controlled-release caps on visual responsiveness of apple maggot fly and found that it had no significant impact on captures. In commercial orchard trials designed to evaluate the potential of attracticidal spheres with contoured caps for direct control of apple maggot, a perimeter-based deployment provided protection comparable to plots receiving 1-2 whole-plot insecticide applications.

The plum curculio, Conotrachelus nenuphar, is a major pest of stone and pome fruit (e.g., apples, pears, peaches, cherries, etc.). Entomopathogenic nematodes (Steinernema spp. and Heterorhabditis spp.) may be used to control the larval stage of C. nenuphar following fruit drop. Indeed, certain entomopathogenic nematodes species have previously been shown to be highly effective in killing C. nenuphar larvae in laboratory and field trials. In field trials conducted in the Southeastern, USA, Steinernema riobrave has thus far been shown to be the most effective species. However, due to lower soil temperatures, other entomopathogenic nematode strains or species may be more appropriate for use against C. nenuphar in the insect's northern range. Thus, the objective of this study was to conduct a broad screening of entomopathogenic nematodes. Under laboratory conditions, we determined the virulence of 13 nematode strains (comprising nine species) in two different soils (a loam and clay-loam) and three different temperatures (12°C, 18°C, and 25°C). Superior virulence was observed in S. feltiae (SN strain), S. rarum (17 C&E strain), and S. riobrave (355 strain). Promising levels of virulence were also observed in others including H. indica (HOM1 strain), H. bacteriophora (Oswego strain), S. kraussei, and S. carpocapsae (Sal strain). All nematode treatments were affected by temperature with the highest virulence observed at the highest temperature (25°C). In future research, field tests will be used to further narrow down the most suitable nematode species for C. nenuphar control.

Apple maggot, Rhagoletis pomonella (Walsh) (Diptera: Tephritidae), is a key pest in apple (Malus spp.) production areas located in the northeastern and midwestern United States and the eastern provinces of Canada. The development of Surround WP has offered a new approach for controlling apple maggot and other tephritid species, because this material is considered to be compatible with advanced integrated pest management and organic production systems. We conducted studies aimed at identifying the behavioral and biological effects of this material on apple maggots. Specifically, we examined the effect of Surround WP on the visual ecology of adult flies under field conditions, on tactile responses of flies in semifield trials, and on fly mortality in laboratory-based-bioassays. We demonstrated that an even coating of white particles over a fruit-mimicking sphere surface reduced visual attractiveness. We also found that spotty-coated fruit-mimicking spheres (meant to mimic ripe fruit bearing an uneven coating of Surround WP) were perceived by flies as not having the ideal round silhouette shape stimulus. Surround WP served as a tactile deterrent; the residence time of females introduced on to treated fruit was much shorter compared with untreated fruit. Surround WP also had a toxic effect on both adult apple maggot and Rhagoletis suavis (Loew); flies exposed to and forced to stand on Surround-treated surfaces died in <2 d in all trials. The combined effectiveness of Surround WP is based on a reduction in the attractiveness of fruit-based visual cues, an increase in the likelihood of flies leaving treated surfaces due to tactile deterrence, and a potential for increased mortality due to exposure to Surround WP particles.

Abstract The plum curculio, Conotrachelus nenuphar (Herbst), is a serious pest of stone and pome fruits (Rosaceae) in eastern North America. We recorded captures of adult plum curculios in the field and measured electroantennogram (EAG) activity in the laboratory associated with cultivars of four hosts, ‘Formosa’ Japanese plum (Prunus salicina Lindl.), ‘Stanley’ European plum (P. domestica L.), ‘Empire’ apple (Malus domestica Borkh.), and ‘Loring’ peach (P. persica (L.) Batsch) (Rosaceae) to determine whether hosts that may be attractive to the plum curculio under field conditions also elicit positive EAG responses. Trap captures of adults on ‘Formosa’ plum were significantly greater than on any other host, and corresponding headspace extracts also produced strong EAG responses throughout the active season. ‘Stanley’ plum and ‘Loring’ peach, the other stone-fruit hosts included in the study, elicited strong EAG responses throughout the season, although trap captures associated with these hosts were generally not as high as for ‘Formosa’ plum. Throughout the season, trap captures of adults were significantly lower for ‘Empire’ apple than for ‘Formosa’ plum, and EAG responses were much lower than for all stone-fruit hosts. Our results indicate that volatiles from ‘Formosa’ plum likely contain uniquecompounds or are comprised of ratios of stimulating compounds that make it much more attractive to plum curculio in the field.

Adult brown stink bugs, Euschistus servus (Say), were caged individually on limbs with apple fruit of 6 cultivars in research orchards in West Virginia. Studies were performed to describe specific characteristics of damage that could be used for field and/or laboratory diagnosis of stink bug injury to apple fruit at harvest. These characteristics were separated into surface and subsurface features. On the apple surface, 3 prevailing types of stink bug injury were observed in the field: (1) a discolored dot, i.e., stink bug feeding puncture; (2) a discolored dot with a depression in the fruit; and (3) a discolored dot with a discolored depression in the fruit. Subsurface characters were related to the extent of damage observed on the fruit skin. Common subsurface damage ranged from a stylet sheath to corky tissue of variable color, shape, and size that sometimes was not contiguous with the skin. Laboratory evaluations under a dissecting microscope revealed that the size of the stink bug feeding puncture was ~0.17 mm diam. This character was the only consistent, definitive symptom of stink bug injury present among all observed damage. Due to variability in other surface and subsurface characters, and potential problems with visual apparency of injury in the field, evaluations of suspected stink bug damage should be performed with 40X magnification in the laboratory to confirm the presence of stink bug feeding punctures.

Reliable electroantennogram (EAG) responses were obtained from the plum curculio, Conotrachelus nenuphar (Herbst), by using a whole body mount with glass electrodes filled with KCl-saturated AgCl solution that penetrated the antennal club (recording electrode) and the membrane attached to the cervical sclerite between the thorax and the head (indifferent electrode). Known attractive odor sources including extracts of headspace collections of 'Stanley' plum and 'Empire' apple tissues and a synthetic source of racemic grandisoic acid were used to verify the sensitivity of the technique. The amplitude of responses was significantly greater for females than males among all candidate stimuli evaluated. The recorded amplitudes for all odor stimuli evaluated were significantly greater than the methylene chloride solvent control. The development of this EAG technique will facilitate use of a coupled gas chromatographic-electroantennographic detection system to aid in detection of novel, biologically and behaviorally active volatile sources that can be subsequently evaluated in behavioral trials and ultimately lead to more powerful attractants for use in monitoring and management programs for plum curculios in commercial fruit orchards.

We assessed host preference of adult plum curculio, Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae), based on the total number of mark-released and wild adults recovered and the total distance moved by mark-released adults in an orchard whose layout was designed to specifically allow foraging plum curculios to choose among host tree species. Host trees included apple, Malus domestica Borkh.; pear, Pyrus communis (L.); peach, Prunuspersica (L.) Batsch; apricot, Prunus armeniaca L.; tart cherry, Prunus cerasus L.; sweet cherry, Prunus avium (L.); European plum, Prunus domestica L.; and Japanese plum, Prunus salicina Lindl. (all Rosaceae). We released 2900 marked adults and recovered 17.7%. We used screen traps to provide a measure of the number of adults that arrived at and climbed up particular host trees and found that significantly greater numbers of marked adults and the greatest number of wild adults were recovered from screen traps attached to Japanese plum. We sampled host tree canopies by tapping limbs to provide a measure of the number of adults within a tree canopy at a particular moment. Again, significantly greater numbers of marked and wild adults were recovered from plum species, with no difference between Japanese and European plum cultivars for marked individuals, but with significantly greater numbers of wild individuals recovered from Japanese plum. The preference index (PI) for Japanese plum based on total distances moved by all marked adults recovered on Japanese plum divided by the total distance moved by marked adults recovered on other host trees indicated that Japanese plum was the most highly preferred host, followed by European plum, peach, sweet cherry, tart cherry, apricot, apple, and pear, respectively.