Vertical distribution of codling moth adults in pheromone-treated and untreated plots

The vertical distribution of codling moth,Cydia pomonella (L.) within pheromone-treated and untreated apple and pear orchard canopies was determined using tethered virgin females, unbaited sticky traps, and blacklight observation of released moths. Mating of virgin females tethered at various heights in untreated orchard canopies increased with placement height from 1–4 m. Application of pheromone dispensers for mating disruption at 2 and 4 m above the ground greatly decreased mating. Greatest capture of males and females on unbaited sticky traps occurred at mid- and upper-canopy heights. Total capture of males and females in pheromone-treated plots was not statistically different than in untreated plots. The percentage of mated females captured on sticky traps did not vary with trap height or pheromone treatment. Released moths marked with flourescent powder and observed at dark with a blacklight indicated that moths are primarily distributed high in the canopy. However, males shifted to a position lower in the canopy when pheromone dispensers were placed 2.1 m above the ground. Results suggest that pheromone dispensers be placed in the upper canopy for optimal disruption of codling moth mating.     

Labelling the blueberry leaftier, Croesia curvalana with foliar sprays of rubidium chloride

The feasibility of labelling blueberry leaftier by rearing the larvae on blueberry plants treated with foliar sprays of rubidium chloride (RbCl) at concentrations of 1000, 5000, 10 000 and 20 000 ppm were assessed. RbCl sprays above 5000 ppm significantly reduced survivorship to adult stage. The adult longevity, fecundity and mating were not affected when the larvae were reared on foliage treated with 5000 ppm RbCl solution. Reciprocal matings of 5000 ppm treated moths with untreated moths revealed transfer of label above the 0.1 µg Rb/insect threshold level from treated males to untreated females (in 8 out of 13 pairs) and vice versa (in 1 out of 9 pairs). Considerable loss of Rb (56–64%) occurred from the leaves over a 15 day period. All of the moths and pupae collected from the RbCl treated plots in 1989 and 1990 respectively, had a Rb content higher than the threshold level. In a preliminary dispersal study, marked male and female moths were found in sweepnet samples collected 20 and 60 m from the centre of the treated field. Labelled male moths were also captured in pheromone traps arranged in a circle, 40 m from the treated plot.     

Effects of sex pheromone in electrostatic powder on mating behaviour by Lobesia botrana males

Abstract:  In laboratory trials, mating behaviour of males of Lobesia botrana Den. and Schiff. (Lep., Tortricidae) was investigated after treatment with an electrostatically chargeable powder, Entostat^TM. Male moths were powdered with either blank Entostat or Entostat containing sex pheromone. Significantly more Entostat adhered to L. botrana males when sex pheromone was added to the powder compared with blank Entostat. Powdering male moths with Entostat, with or without sex pheromone, caused a significant reduction in antennal response when antennae were placed 2 cm away in downwind direction, while there was little effect when antennae were placed 25–100 cm from the EAG in downwind direction. In a flight study, powdering males of L. botrana caused significant increase in time before flight initiation and reduction in proportion of males making contact with calling females compared with untreated males. In a mating experiment in Petri dishes (to minimize required search time to locate female), significantly fewer females mated successfully (based on dissection of bursa copulatrix) when males had been treated with pheromone-loaded powder. Overall, powdering males of L. botrana caused considerable suppression of mating behaviour on various levels, and these suppressing effects were increased after adding sex pheromone to Entostat.     

The behavioural basis of a pheromone monitoring system for pea moth, Cydia nigricana

The flight and mating behaviour of the pea moth (Cydia nigricana) was studied at overwintering sites and in pea fields to see whether it could be exploited to provide early warning of adult immigration into pea crops. The field threshold temperature for take-off is 18 ^CC. Most flight activity-occurred in June and July between 16.00 and 18.00 B.S.T. with peak activity at 17.04 h. Moths were not caught in suction traps at heights above 0–4 m, but they can probably travel several km by fluttering above vegetation in winds of up to 10 km/h. Female moths produce a sex pheromone(s) highly attractive to males; ‘calling’ by females and mating occur during the period of maximum flight activity. Suction traps and egg counts detected the presence of moths in crops at about the same time. On average, sticky and water traps containing live virgin females as a lure caught respectively 17 and 130 times more males than suction traps and, on occasions, 25 and 300 times more; these attractive traps should detect the arrival of immigrants sooner than suction traps or egg counts. Extracts of virgin females dispensed from filter paper at doses of one and five female-equivalents (FE) attracted males rapidly but temporarily. Rubber dispensers with extracts of twenty FE remained attractive for 6 days. Several synthetic attractants were screened using doses of o-i mg on rubber dispensers in sticky traps. CYs-8-dodecenyl acetate and erans-8, frans-io-dodeca-dienol at doses of o-i mg were slightly attractive; the latter at doses of 1 -o mg was more attractive than twenty FE doses of extract and could be used for experimental monitoring of pea moth until its own synthetic sex pheromone(s) is available.     

Effects of intentional gaps in spray coverage on the efficacy of gypsy moth mating disruption

Abstract:  The study was conducted during 2001 and 2002 in forested areas in Virginia, US to examine the effects of gaps in coverage of pheromone on gypsy moth, Lymantria dispar (L.) (Lep., Lymantriidae), mating disruption. Gypsy moth male moth catches in pheromone-baited traps were significantly reduced in plots treated with the gypsy moth sex pheromone, disparlure, at an overall application rate of 37.5 g of active ingredient (AI)/ha but with untreated gaps of 30 or 90 m between 30-m wide treated swaths. In one of the two plots with 90 m gaps, significantly more males were captured in traps in the untreated areas compared with the treated areas within the plot. However, in another plot, significant differences in trap catches between treated and untreated areas were not observed. No difference in male moth catches in the pheromone-baited traps was observed between treated and untreated areas within the plots treated with 30 m gaps. Female mating success did not differ significantly between treated and untreated areas within the one plot in which it was measured. These results suggest that it may be possible to lower costs associated with gypsy moth mating disruption applications by alternating treated and untreated swaths, which would reduce flight time and fuel costs, without a reduction in efficacy.     

二化螟雄蛾交配行为与精巢大小的关系

【目的】为了明确二化螟Chilo suppressalis雄蛾交配行为与精巢大小的关系,阐明信息素群集诱杀防治二化螟的有效性。【方法】本研究通过测定和比较不同日龄、交配状态以及性信息素诱捕的二化螟雄蛾精巢体积,建立精巢体积与雄蛾发育及交配状态的相关性。【结果】雄蛾日龄显著影响二化螟的交配,刚羽化(0日龄)雄蛾的交配率较低,1日龄雄蛾的交配率最高,之后随着日龄增加交配率逐渐降低。精巢体积与二化螟雄蛾日龄之间存在显著的负相关性。同一日龄交配的二化螟雄蛾的精巢体积显著大于未交配雄蛾;性诱捕器诱捕雄蛾的精巢体积显著大于未被性诱捕器诱捕雄蛾,与已交配雄蛾的精巢体积相似。交配之后,精巢的发育过程和未交配雄蛾相似。田间性信息素引诱二化螟雄蛾精巢体积小于0-1日龄未交配雄蛾,大于2-6日龄未交配雄蛾。【结论】本研究结果表明,二化螟雄蛾对雌蛾性信息素的反应与其精巢大小存在正相关性;性信息素引诱的二化螟雄蛾具有更强的性信息素反应能力,同时性信息素引诱的大部分雄蛾为未交配状态;交配过程并不影响二化螟雄蛾精巢体积,也不影响精巢发育。二化螟交配能力与精巢大小的关系在理论上解释了性信息素群集诱杀二化螟的防控有效性,并为其他蛾类昆虫的交配研究提供依据。     

Movement of the grape berry moth, Endopiza viteana: displacement distance and direction

Abstract. Mark–release–recapture is used to quantify displacement by adults of the North American grape berry moth, Endopiza viteana Clemens (Lepidoptera: Tortricidae) under field conditions. Moths marked with fluorescent dust are released eight times in the centre of a vineyard over 2 years, and recaptured using pheromone traps and interception traps. In vineyards, male moths are recaptured an average of 13.8 ± 0.8 m from the release site (maximum 58.2 m), whereas female displacement is similar with average flight distances of 11.4 ± 6.7 m (maximum 41.2 m). Increasing wind speed during moth flight activity periods suppresses displacement by both sexes, and females are less likely than males to fly in winds above 0.6 m s^?1. The majority of males are recaptured upwind from the release site or at a tangent to the overall mean wind direction when responding to pheromone traps, whereas female moths trapped in interception traps exhibit a large variability in direction from the release point. Releases of marked moths in woods adjacent to a vineyard demonstrates interhabitat movement by E. viteana males and by a single female. The average maximum displacement by males during interhabitat movement is 105.4 ± 3.9 m, significantly greater than the average maximum of 39.7 ± 6.7 m inside the vineyard habitat.     

Disruption of the odour-mediated mating behaviour of Plodia interpunctella using high-frequency sound

Abstract Indian meal moths, Plodia interpunctella Hübner (Lepidoptera: Pyralidae), have ears which are sensitive to high‐frequency calls produced by echolocating, insectivorous bats. The influence of artificially generated, high‐intensity, ultrasound signals (25 kHz, 106 dB SPL at 1 m distance) on different parameters involved in the odour‐mediated mating behaviour of this species and its potential use in population control was investigated. All moths flying towards olfactory cues in flight tunnel experiments reacted strongly to a 1 s ultrasound pulse by cessation of flight and falling out of the odour plume. The source contact proportion of both male moths orienting towards the female‐produced sex pheromone and of mated female moths orienting towards an oviposition cue was reduced by 40%, compared to unexposed moths. Calling females responded to the sound by retraction of the ovipositor or by falling to the ground. Long‐term exposure to repetitive pulses of ultrasound suppressed female calling by up to 27%. Furthermore, mating in plastic tents was disrupted by up to 58% in ultrasound‐treated tents using different sound regimens, compared to control tents. The results are discussed in relation to the potential use of ultrasound technology for the population control of pyralid stored product pests.     

Comparison of efficacy of pheromone dispensing technologies for controlling the grape berry moth (Lepidoptera: Tortricidae) by mating disruption

The efficacy of 3M Sprayable Pheromone for Grape Berry Moth, BASF RAK 1R pheromone dispensers, Isomate GBM pheromone dispensers, and an insecticide program were compared during two seasons for controlling grape berry moth, Endopiza viteana (Clemens), in Niagara peninsula, Ontario, Canada, vineyards. The average number of E. viteana captured in pheromone-baited traps in plots treated with BASF RAK 1R and Isomate GBM dispensers was reduced by 90-100% compared with the average number captured in insecticide-treated plots, indicating a high level of mating disruption. By contrast, there was no difference in the number of moths captured in plots treated with sprayable pheromone and in plots treated with insecticide during the second flight of 1999, suggesting that the sprayable pheromone did not affect the mate-seeking ability of male moths. During the third flight of 1999, and the three flights of 2000, however, the average number of E. viteana captured in plots treated with sprayable pheromone was reduced by 50-99% compared with the average number captured in insecticide-treated blocks, indicating a moderate-to-high level of mating disruption. There was no detectable difference in feeding injury to grape clusters when E. viteana was controlled using two application rates of a sprayable pheromone formulation, two hand-applied pheromone dispensers, or a conventional, insecticide-control program. The disparity between estimated disruption and crop damage in plots treated with sprayable pheromone during the second flight of 1999 suggests that pheromone-baited traps may not provide a reliable estimate of the level of mating disruption when using sprayable pheromone.     

Female moths of cotton bollworm (Lepidoptera: Noctuidae) captured by waterbasin traps baited with synthetic female sex pheromone

Cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), is one of the most important pest insects in cotton fields in China. Female moths were captured by waterbasin traps with a synthetic female sex pheromone blend in cotton fields over three years. The blend contained (Z)‐11‐hexadecenal and (Z)‐9‐hexadecenal with a ratio of 97:3. Each pheromone dispenser was impregnated with 2.0 mg of pheromone blend and 0.2 mg of antioxidant dissolved with 0.1 mL of hexane, and there was a control dispenser with a similar amount of antioxidant and solvent only. Waterbasin traps were deployed in three configurations in the fields. ‘A’ was pheromone traps only, ‘B’ was both pheromone and control traps, ‘C’ was control traps only. (i) In four plots of ‘A’, the average weekly female catch was 1.5, and more females were captured by centrally located pheromone traps, (ii) In three plots of ‘Brsquo;, control traps also captured female as well as male moths, but average weekly female catches of control traps was significantly lower than that in pheromone‐baited traps. (iii) There were significant linear relationships between the average weekly female catch and the corresponding layer in pheromone‐baited traps in both ‘A’ and ‘B’ plots, and in quadratic equations in control in ‘B’ plots. (iv) With the increase of the interval of traps, average weekly female catches per trap increased but average weekly female catches per hectare decreased. (v) Among the female moths captured by pheromone traps, 88.3% were mated female moths which each containing 1.46 spermatophores, while in control traps 86.9% of the mated female moths had 0.90 spermatophores. There was a significant difference between the average numbers of spermatophores of mated females in pheromone traps and in controls.     

Attractiveness and competitiveness of irradiated light brown apple moths

The sterile insect technique (SIT) potentially provides a socially acceptable approach for insect eradication of new pest incursions. The light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), was discovered in Berkeley (CA, USA) in 2006, leading to an incursion response that included this technology. In this study, we assessed factors affecting mating success from a bisex release of irradiated moths: effects of radiation dose on male multiple mating, male flight competition, female sex pheromone titre and attractiveness of irradiated females to males, and identification of successful mating in vineyards of either irradiated or wild males (identified by isotope analysis of spermatophores from sentinel females). There was a significant negative relationship between male radiation dose and mating frequency. In head‐to‐head flights of irradiated males against non‐irradiated males to a pheromone lure in a wind tunnel, irradiated males reached the lure first only 31% of the time. With increasing radiation dose, the production of the major sex pheromone component in females, (E)‐11‐tetradecenyl acetate, dropped, from 0.7 ± 0.1 ng per female in non‐irradiated females to 0.2 ± 0.07 ng per female when irradiated at 300 Gy. Male catch was reduced to 11% of control females in traps containing females irradiated at 300 Gy. Isotope analysis of spermatophores found in the bursa copulatrix of females indicated that mating success of irradiated males inside the live (entry‐only) traps containing virgin females was lower (13.1 ± 3.3%) than suggested by male catch (21.2 ± 3.8%) in pheromone traps, the current standard for assessing field competitiveness. Impacts of irradiation on male and female moth fitness should be taken into account to improve estimates of irradiated to wild male E. postvittana overflooding ratios needed for population suppression.     

Modelling female mating success during mass trapping and natural competitive attraction of searching males or females

Simulation models of insects encountering sex pheromone with or without mass trapping in which the searching sex is either male (moths and many insect species) or female (some true bugs, beetles, and flies) were developed. The searching sex moved as a correlated random walk, while the opposite sex remained stationary (calling) and released an attractive sex pheromone. The searching sex was caught when encountering a pheromone‐baited trap, and females mated when encountering a male. An encounter with pheromone was defined by the searcher's interception of a circle termed the effective attraction radius (EAR_c). Parameters of movement (speed and duration), initial numbers of calling sex and searching sex, number of traps, area, and EAR_c of traps and calling sex were varied individually to evaluate effects on the percentage of females mating. In the natural condition without traps, female mating success in both models was identical. Increasing the EAR_c of the calling sex caused diminishing increases in female mating success, suggesting that evolution of larger pheromone release and EAR_c is limited by increasing costs (production/sensitivity) relative to diminishing increases and benefits of mating encounters. With mass trapping, increasing the EAR_c of traps or density of traps caused similar declines in female mating in both models, but the female‐searching model predicted slightly lower mating success than the male‐searching model. Increasing the EAR_c of calling insects or the initial density of insects caused similar increases in female mating in both models, but again the female‐searching model had slightly lower mating success than the male‐searching model. The models have implications for mating lek formation and for understanding the variables affecting the success of mass trapping programs for insect pests with either male or female sex pheromones.     

Comparison of mating disruption with pesticides for management of oriental fruit moth (Lepidoptera: Tortricidae) in North Carolina apple orchards

The efficacy of mating disruption by using Isomate-M 100 pheromone dispensers and two formulations of microencapsulated sprayable pheromone for management of oriental fruit moth, Grapholita molesta (Busck), was compared with conventional insecticides in large plot studies in Henderson County, North Carolina, in 2000 and 2001. In addition, experiments were conducted in small and large plots to test the response of oriental fruit moth males to different application rates of sprayable pheromone. Pheromone trap catches were significantly reduced in mating disruption blocks compared with conventional and abandoned orchards. Pheromone traps placed in the upper canopy captured significantly more moths than traps placed in the lower canopy across all treatments, and lures loaded with 100 microg of pheromone caught more moths than traps with 300 microg, but the difference between doses was statistically significant at only one location in 2001. Isomate-M 100 provided excellent trap shutdown and was significantly more effective than sprayable pheromone formulations. Fruit damage by oriental fruit moth larvae was very low (< or = 1%) in mating disruption blocks and was generally lower than in conventional and nonmanaged blocks. Based on male moth response to pheromone traps in small plots, there was little difference among doses of sprayable pheromone, ranging from 12.4 to 49.1 g (AI)/ha, but efficacy declined at 2.4 g (AI)/ha. With the exception of one orchard, there was no significant difference between 12.4 and 37.1 g (AI)/ha under low and high oriental fruit moth population pressure in large plot studies. Mating disruption proved to be an alternative to organophosphate insecticides for managing oriental fruit moth populations in North Carolina apple orchards.     

Potential for mating disruption of Sparganothis sulfureana (Lepidoptera: Tortricidae) in cranberries.

The feasibility of disrupting mating of Sparganothis fruitworm with a sprayable microencapsulated formulation of (E)-11-tetradecenyl acetate (E11-14:Ac), the major pheromone component, was evaluated in New Jersey during 1996 and 1997 seasons. In both years, application of encapsulated E11-14:Ac, at 25-187.5 g (AI)/ha, reduced the incidence of mating of virgin females placed in treated plots relative to those placed in control plots. Pheromone trap catches were lower in pheromone treated plots, indicating that fewer male moths were able to locate the traps in treated plots. Larval density and fruit damage were significantly lower in plots treated with 62.5,125, or 187.5 g (AI)/ha of pheromone than in the untreated control. Air and foliage samples were collected to determine the air titers and foliage residuals of E11-14:Ac throughout the adult flight during 1996 and 1997. E11-14:Ac levels in air and foliage samples, declined sharply one wk after the pheromone application. However, detectable levels of E11-14:Ac were present in both air and foliage samples throughout the 3- to 4-wk period after the pheromone application. Multiple applications of pheromone at lower rates may be more effective in maintaining pheromone levels than a single dose at higher rates. These results suggest that mating disruption is a promising strategy to manage Sparganothis fruitworm in cranberries.     

Attraction of the sexes inFormica lugubris Zett (Hymenoptera: Formicidae)

Summary Sexuals ofFormica lugubris fly to mating places, where females attract males by using a sex pheromone. Females collected on the nest surface before departing on a mating flight are much less attractive than those collected on the mating place after the mating flight, suggesting that the mating flight triggers the release of the sex pheromone. Olfactory cues are essential for males to locate females while they patrol. Males probably use visual cues to locate females once they have alighted nearby them. Males are also attracted by aggregations of other males on the ground, probably because one or several females are likely to be close to male aggregations.     

Sexual differences in the flight performance of the oriental fruit moth, Cydia molesta

Cydia molesta Busck (Lepidoptera: Tortricidae), a major pest of stone fruits and an increasingly important late season pest of apple, is predominately monitored by pheromone trapping of male moths. We investigated flight performance in relation to sex, age, and mating status using computer-linked flight mills, and also examined the relationship between female flight and reproduction. The crepuscular flight pattern of the experimental moths in relation to photointensity was very similar to that reported from field studies. Female moths significantly outperformed males in all measured flight parameters including total distance flown, distance of longest single flight, and velocity. The proportion of long-flying females (categorised as those completing an unbroken flight of greater than 1 km) was three to six times greater than that of males. Female flight performance was not related to mating status, but mated males displayed significantly greater flight than unmated males. The maximal flight period of mated females commenced on the third day after eclosion, following 30% egg deposition. Male flight was not significantly related to age. The data suggest that a limited proportion of the population, in particular females, may have the capacity to make inter-orchard flights. The limitations of monitoring C. molesta populations in apple orchards solely by pheromone trapping of males are discussed.     

Concurrent modulation of neuronal and behavioural olfactory responses to sex and host plant cues in a male moth

Mating has profound effects on animal physiology and behaviour, not only in females but also in males, which we show here for olfactory responses. In cotton leafworm moths, Spodoptera littoralis, odour-mediated attraction to sex pheromone and plant volatiles are modulated after mating, producing a behavioural response that matches the physiological condition of the male insect. Unmated males are attracted by upwind flight to sex pheromone released by calling females, as well as to volatiles of lilac flowers and green leaves of the host plant cotton, signalling adult food and mating sites, respectively. Mating temporarily abolishes male attraction to females and host plant odour, but does not diminish attraction to flowers. This behavioural modulation is correlated with a response modulation in the olfactory system, as shown by electro-physiological recordings from antennae and by functional imaging of the antennal lobe, using natural odours and synthetic compounds. An effect of mating on the olfactory responses to pheromone and cotton plant volatiles but not to lilac flowers indicates the presence of functionally independent neural circuits within the olfactory system. Our results indicate that these circuits interconnect and weigh perception of social and habitat odour signals to generate appropriate behavioural responses according to mating state.     

Effects of the 3M™ MEC Sprayable Pheromone® formulation on gypsy moth mating success

The study was conducted during 2000, 2001, 2003 and 2004 in forested areas in Virginia, USA to evaluate the 3M™ MEC-GM Sprayable Pheromone® formulation of the gypsy moth sex pheromone, disparlure, for its ability to disrupt mating in gypsy moth, Lymantria dispar (Lep.: Lymantriidae). Both mating success of gypsy moth females and male moth catches in pheromone-baited traps were significantly reduced in plots treated with the 3M™ MEC-GM formulation at dosages ranging from 15 to 75 g of active ingredient/ha. However, the 3M™ MEC-GM formulation reduced trap catch to a lesser extent than did the currently registered Hercon Disrupt® II plastic flakes used as a positive control and applied at similar or lower dosages. Furthermore, the effectiveness of the 3M™ sprayable formulation declined through time, so that by the end of the male flight season, male moth catches in traps were significantly higher than in plots treated with Hercon plastic flakes. Based on the reported results, 3M™ MEC-GM Sprayable Pheromone® formulation was never integrated into the operational treatment projects of USDA Forest Service Cooperative Slow-the-Spread of the Gypsy Moth management programme.     

Development of pheromone-based mating disruption for control of the eye-spotted bud moth, Spilonota ocellana

The potential for pheromone-based mating disruption of eye-spotted bud moth (ESBM), Spilonota ocellana (Denis & Schiffermüller) (Lepidoptera: Tortricidae), in apple orchards in the Okanagan Valley of British Columbia was examined in small-plot trials. In a preliminary experiment, treatment of the orchard atmosphere with a 99:1 blend of Z8-tetradecenyl acetate (Z8-14:OAc) and Z8-tetradecenyl alcohol (Z8-14:OH) completely inhibited captures of male ESBM in pheromone-baited traps, but treatment with Z8-14:OAc alone did not. Therefore, all subsequent trials used the two-component blend as a disruptant. Mean catches of male ESBM in traps baited with 0.1, 1, 10, or 20 mg of 99:1 Z8-14:OAc and Z8-14:OH were significantly reduced (81–97%) in pheromone-treated plots relative to similar traps placed in control plots. In both control and treated plots, there was a significant positive relationship between trap bait dose and trap catch. In pheromone-treated plots, this suggests that high doses of trap baits over-ride the camouflage effect of disruption or overcome the effect of sensory adaptation and habituation. The number of virgin-female baited traps capturing at least one male ESBM was reduced by 96%, and mating of virgin females on mating tables was reduced by 95% in plots treated with the two-component pheromone. The total amount of Z8-14:OAc released from pheromone disruption dispensers during the latter field trials was estimated to average 6.4 g ha^-1 over 11 days or 26.4 mg ha^-1 h^-1. The low levels of Z8-14:OH released from disruption dispensers could not be estimated by GC analysis. Dispensers loaded with a 99:1 blend of Z8-14:OAc and Z8-14:OH were highly attractive to males in baited traps, indicating that they have the potential to induce false trail following.     

Influence of within-orchard trap placement on catch of codling moth (Lepidoptera: Tortricidae) in sex pheromone-treated orchards

The influence of trap placement on catches of codling moth, Cydia pomonella L., was examined in a series of studies conducted in orchards treated with Isomate-C Plus sex pheromone dispensers. Mark-recapture tests with sterilized moths released along the interface of pairs of treated and untreated apple and pear plots found that significantly more male but not female moths were recaptured on interception traps placed in the treated plots. In a second test, significantly higher numbers of wild male and female moths were caught on interception traps placed in treated versus untreated plots within a heavily infested orchard. The highest numbers of male moths were caught on traps placed along the interior edge of the treated plots. Trap position had no influence on the captures of female moths. In a third test, north-south transects of sex pheromone-baited traps were placed through adjacent treated and untreated plots that received a uniform release of sterilized moths. Traps on the upwind edge of the treated plots caught similar numbers of moths as traps upwind from the treated plots. Moth catch was significantly reduced at all other locations inside versus outside of the treated plots, including traps placed on the downwind edge of the treated plot. In a fourth test, five apple orchards were monitored with groups of sex pheromone-baited traps placed either on the border or at three distances inside the orchards. The highest moth counts were in traps placed at the border, and the lowest moth counts were in traps placed 30 and 50 m from the border. In a fifth test, the proportion of traps failing to catch any moths despite the occurrence of local fruit injury was significantly higher in traps placed 50 versus 25 m from the border. The implications provided by these data for designing an effective monitoring program for codling moth in sex pheromone-treated orchards are discussed.