Pheromone-baited Trap Research Articles

Zoophytophagous predator sex pheromone and visual cues of opposing reflectance spectra lure predator and invasive prey.

In sub-Saharan Africa, the invasive South American leafminer Phthorimaea absoluta is the most damaging tomato pest. Females of the pest can reproduce both sexually and through parthenogenesis and lay their eggs on all tomato plant parts. The mirid predator Nesidiocoris tenuis, a biological control agent for the pest, is also a tomato pest when prey population is low. To date, however, no study has developed an eco-friendly solution that targets both the predator and its host in a tomato farming system. To develop a bio-based management system for both pest and predator based on the combined use of sexual communication in the predator and visual cues. We collected volatiles from both sexes of the Kenyan population of the predator N. tenuis and identified candidate sex pheromone components by coupled gas chromatography-mass spectrometry (GC-MS). We used electrophysiological assays to identify antennally-active odorants in the volatiles, followed by field trials with different pheromone-baited colored traps to validate the responses of both predator and prey. Thereafter, we compared the reflectance spectra of the colored traps with those of different tomato plant tissues. Our results reveal an interplay between different sensory cues which in the predator-prey interaction may favor the predator. Antennae of both sexes of predator and prey detect the predator sex pheromone identified as 1-octanol and hexyl hexanoate. Unexpectedly, our field experiments led to the discovery of a lure for P. absoluta females, which were lured distinctly into a pheromone-baited trap whose reflectance spectrum mimicked that of ripe tomato fruit (long wavelength), an egg-laying site for females. Contrastingly, N. tenuis males were lured into baited white trap (short wavelength) when the predator is actively searching for prey. Our results demonstrate the novel use of a predator sex pheromone and different visual cues to assess complex trophic interactions on tomatoes.

Effect of Trap Type and Height on the Captures of the Pink Bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), in Pheromone-Baited Traps in Cotton

The impact of trap type and height on the captures of adults of the pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), was assessed in cotton fields in three experimental sites (Nikaia, Nees Karyes, and Koilada) in Central Greece. Initially, the effectiveness of three different traps (white Delta, red Delta, and green Funnel) was compared. Subsequently, white Delta traps were positioned at three heights, i.e., 30, 60, and 90 cm, above ground level. Overall, captures notably increased in all traps from late July to mid-September. Funnel traps had poor performance for the captures of P. gossypiella adults, as compared with the respective figures for the other two Delta traps. Specifically, in two experimental sites (Nikaia and Koilada), both Delta traps cumulatively captured significantly more adults than the Funnel trap throughout the monitoring period. In the third site (Nees Karyes), the red Delta trap captured in total significantly more adults than the other two tested traps. Moreover, we found that traps in Nikaia placed at 90 cm captured significantly less adults as compared with the other two trap heights. The same trend was observed in Koilada; however, differences were significant only between traps at 30 and 90 cm. No significant differences were determined among different heights in the third site (Nees Karyes). These findings offer valuable insights for the monitoring protocols of P. gossypiella in cotton fields, on the basis of a standardized trapping strategy, that can take into account a wide range of factors, such as trap design and trap height.

Acetophenone and Green Leaf Volatiles Do Not Enhance the Efficacy of Verbenone for Inhibiting Attraction of Ips pini (Coleoptera: Curculionidae) to Pheromone-baited Traps in Northern Arizona.

We assessed attraction of pine engraver, Ips pini (Say) (Coleoptera: Curculionidae; Scolytinae), to pheromone-baited funnel traps treated with repellent semiochemicals in ponderosa pine, Pinus ponderosa var. scopulorum Engelm., forests in northern Arizona. Treatments included: 1) baited control (B, ipsdienol + lanierone), 2) 70 g of SPLAT Verb (a flowable, biodegradable formulation containing 10% verbenone, ISCA Technologies Inc., Riverside, CA, USA) + B, 3) 70 g of SPLAT Verb + (E)-2-hexen-1-ol+(Z)-2-hexen-1-ol + acetophenone + B, 4) 7.84-g verbenone pouch (Product #3413, Synergy Semiochemicals Corp., Delta, British Columbia, Canada) + B, and 5) 7.84-g verbenone pouch + (E)-2-hexen-1-ol+(Z)-2-hexen-1-ol + acetophenone + B. In total, 472 I. pini were collected. Trap catches were highest in baited traps and declined significantly with the addition of both formulations of verbenone. Traps treated with SPLAT Verb caught significantly fewer I. pini and male I. pini than those treated with verbenone pouches. The addition of (E)-2-hexen-1-ol+(Z)-2-hexen-1-ol + acetophenone to SPLAT Verb and the verbenone pouch had no effect on trap catch. Verbenone has potential as an effective tool for protecting P. ponderosa trees and slash from I. pini in northern Arizona, but the addition of (E)-2-hexen-1-ol+(Z)-2-hexen-1-ol + acetophenone to verbenone is unwarranted.

Host odour alpha-pinene increases or reduces response of Ips avulsus (Coleoptera: Curculionidae: Scolytinae) to its aggregation pheromone, depending on separation of release points

Abstract Monoterpenes in the resin of host trees are important host-location and -selection signals for conifer-infesting bark beetles and can increase or reduce responses to aggregation pheromones. Research on this interaction has been largely limited to collocated release points of the semiochemicals; however, sources are often separated in nature. I performed a trapping experiment to investigate whether distance between semiochemical release points influences how host monoterpene alpha-pinene affects Ips avulsus (Eichhoff) (Coleoptera: Curculionidae) response to its aggregation pheromone (ipsdienol and lanierone). High release (8 g/day) of alpha-pinene from a pheromone-baited trap caused a reduction in catches, but the same release of alpha-pinene from 4 m away significantly increased catches relative to pheromone alone. A low release (0.06 g/day) of alpha-pinene with either arrangement had no effect. Hence, a host odour released at rates sufficient to deter I. avulsus responses to its pheromone may nevertheless enhance attraction if the release point is sufficiently displaced from the pheromone source. The result suggests that, for I. avulsus, the semiochemical alpha-pinene may influence host finding and close-range assessment of host suitability in different ways. Operational lure formulations for some species of bark beetle might be improved by separating pheromone and host odour components or by adding a displaced host odour device.

Pheromone-Baited Traps Confirm the Presence of Duponchelia fovealis1 in Strawberry Crops in Mexico

We confirmed the presence of European pepper moth, Duponchelia fovealis Zeller (Lepidoptera: Crambidae), in Mexico. Pheromone-baited traps caught D. fovealis males, and larvae were collected from strawberry (Fragaria x ananassa Duchesne) fruit in the state of Michoacán.

Performance of Pheromone-Baited Traps to Monitor the Seasonal Abundance of Tortrix Moths in Chestnut Groves

Simple SummaryInvestigations were performed in 2018–2019 in chestnut groves in northern Italy to monitor the seasonal flight activity of Pammene fasciana (L.), Cydia fagiglandana (Zeller), and C. splendana (Hübner) with pheromone-baited traps. Commercially available and experimental pheromone blends were tested. Newly formed chestnut husks and fruits were randomly collected to evaluate damage. Damage was correlated with trap catches. P. fasciana was present in all the sites, while Cydia species were recorded in three of six sites, with differences in abundance related to pheromone blends studied. Several morphologically similar non-target species occurred, highlighting the risk of overestimating catches. Fruit damage did not correlate with trap captures, suggesting that monitoring probably underestimates the true size of the moths’ populations. These data contribute to ascertaining the presence of tortrix moths in northern Italian chestnut groves, and are important for planning specific control measures.(1) Background: Pammene fasciana (L.), Cydia fagiglandana (Zeller), and C. splendana (Hübner) (Lepidoptera: Tortricidae) are considered key moth pests of chestnut in Europe. (2) Methods: Investigations were performed in 2018–2019 in northern Italy. Sticky traps and commercially available pheromones were used for monitoring; moreover, two experimental pheromone blends were tested. All specimens were identified according to male genitalia and molecular analyses. Newly formed chestnut husks and fruits were randomly collected to evaluate the presence of larvae and/or feeding damage, by comparing it to trap catches. (3) Results: P. fasciana was present in all the sites, whereas Cydia species were recorded in three sites of six, with differences in abundance related to pheromone blends studied. Several non-target species, such as Oegoconia novimundi (Busck) and Cydia ilipulana (Walsingham), were present. Data about the seasonal flight activity are provided. (4) Conclusions: This research contributes to ascertaining the presence and abundance of tortrix moths in Italian chestnut groves, and the presence of non-target species highlights the risk of overestimating catches. Fruit damage recorded did not always reflect catches made by pheromone traps, suggesting that monitoring may underestimate the real size of moths’ populations. All of the data acquired are important for planning specific control measures.

Bounds on Absolute Gypsy Moth (Lymantria dispar dispar) (Lepidoptera: Erebidae) Population Density as Derived from Counts in Single Milk Carton Traps.

Estimates of absolute pest population density are critical to pest management programs but have been difficult to obtain from capture numbers in pheromone-baited monitoring traps. In this paper, we establish a novel predictive relationship for a probability (spTfer(r)) of catching a male located at a distance r from the trap with a plume reach D.

Sharpening the Precision of Pest Management Decisions: Assessing Variability Inherent in Catch Number and Absolute Density Estimates Derived from Pheromone-Baited Traps Monitoring Insects Moving Randomly.

During a trapping study interval, each target insect is either caught or not caught. Therefore, the current analysis treats trapping as a binomial process. Data from a binomial calculator, along with computer simulations of random walkers, documented that the inherent variance associated with estimates of absolute population density generated by a single catch number in a pheromone-baited monitoring trap becomes very high when catch probability averaged across the trap's sampling area falls below 0.02, as is the case for most insect trapping systems operating in the open field. The imprecision associated with interpretations of single catch numbers renders many current pest management decisions risky and unsatisfactory. Here we reinforce how single-trap, multiple-release experiments can and should be used to measure catch probability, plume reach, and trap sampling area. When catch probability lies in the danger zone below 0.02, steps are suggested for how multiple traps might be deployed to raise composite catch probability to a level where estimates of absolute pest density become reliable. Heat transfer is offered as an appropriate conceptual model for the mechanics of trapping. A call is made for a radical rethinking in the designs of insect monitoring traps in light of their significant current deficits highlighted by this study.

Estimating Monitoring Trap Plume Reach and Trapping Area for Nymphal and Adult Halyomorpha halys (Hemiptera: Pentatomidae) in Crop and Non-crop Habitats.

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), the brown marmorated stink bug, is an invasive polyphagous insect that can cause serious economic injury to specialty and row crops in the United States and globally. To date, H. halys has been managed with repeated insecticide applications. While progress has been made toward development of trap-based monitoring tools to guide management decisions, little is known regarding the trapping area over which a single pheromone-baited trap captures H. halys. We conducted single trap, multiple distance mark-release-recapture experiments; results were used to estimate trapping area for nymphs and adults in sites without host plants present (open field) and for adults in sites with host plants present (apple orchard). Plume reach for pheromone-baited sticky traps was consistently estimated to be <3 m. Maximum dispersive distance in an open field devoid of host plants was estimated to be 40 m for nymphs and 120-130 m for adults resulting in trapping areas of 0.58 ha and 4.83-5.56 ha, respectively. When traps were deployed in association with host plants within the border row of an apple orchard, adult maximum dispersive distance and trapping area was reduced to 70 m and 1.67 ha, respectively. These results indicate that the behavioral response of H. halys to pheromonal stimuli is influenced by the presence of host plants and that trapping area for pheromone-baited traps will likely change relative to the cropping system in which it is deployed. Caution should be taken when extrapolating these results, because the measured values may differ in other crop systems.

A Physical Barrier Reduces Capture of Euschistus servus (Hemiptera: Pentatomidae) in Pheromone-Baited Traps Near Peach Trees

Many species of stink bugs (Hemiptera: Pentatomidae) are pests of many crop plants and the polyphagous nature of these pests facilitates their movement across farmscapes. However, when feeding, their movement generally entails short distance moves within the height of the host plant. During 2014 and 2015, we used a tall barrier fence around peach trees to determine if this structure would deter adult Euschistus servus (Say) (Hemiptera: Pentatomidae) from being attracted to a pheromone-baited trap near the tree. Each year, cumulative data showed a significant decrease in capture of E. servus in traps enclosed with the barrier fence compared to traps near trees without the fence. Differences in treatments between sampling dates were not always significant. Overall, the barrier fence did reduce attraction of E. servus to pheromone-baited traps near peach trees. Future studies will assess the effect of physical barriers enclosing larger areas of an orchard on stink bug movement into peach, and if fruit injury is reduced.

Influence of Pheromone-Baited Traps on Stink Bugs in Cotton.

Stink bugs (Hemiptera: Pentatomidae) are economic pests in fruit, vegetable, grain, and row crops worldwide. Pyramid traps baited with lures of stink bug aggregation pheromones capture these pests in the field, but stink bugs can congregate on plants near traps. Our specific objective was to examine the area of arrestment of stink bugs based on their density on cotton at different distances from pheromone-baited traps. We used lures of the aggregation pheromone of Euschistus spp., methyl (2E,4Z)-2,4-decadienoate (MDD), and Plautia stali Scott, methyl [2E,4E,6Z]-2,4,6-decatrienoate (MDT). Overall, Euschistus servus (Say), Euschistus tristigmus (Say), Chinavia hilaris (Say), and Nezara viridula (L.) were the main stink bug species on cotton. Over the 3-yr study, adult stink bug density was significantly higher on the row of cotton immediately adjacent to a pheromone-baited trap than on the second and third row from the trap. Stink bug density was significantly lower on the seventh cotton row beyond the trap in 2015, on the fourth, eighth, and 16th rows in 2017, and on the fourth and eighth rows in 2018 compared to the two or three rows nearest the trap. These results indicate that adult stink bugs congregated mainly on the three cotton rows (2.73 m in width) nearest a trap. Management strategies utilizing pheromone-baited traps for stink bug control, such as trap cropping in combination with traps, should take into consideration this area of arrestment.

Effect of trap type and height in monitoring the orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae) and its parasitoid, Macroglenes penetrans (Kirby) (Hymenoptera: Pteromalidae)

The orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), is a common pest of wheat that is frequently parasitized by Macroglenes penetrans (Kirby) (Hymenoptera: Pteromalidae). Both species need to be detected and quantified using a reliable monitoring system to assess the risk for wheat crops and, if necessary, determine the timing of insecticide treatments in order to ensure their efficiency against the pest and prevent adverse side-effects on beneficial insects. Four trap types, placed at 0.6 m above ground level, were compared for their efficiency in catching S. mosellana and M. penetrans: yellow sticky traps, white sticky traps, yellow water traps and pheromone-baited traps. For the pheromone-baited and yellow water traps, three heights (0.2, 0.6 and 1 m above ground level) were tested. For S. mosellana, the pheromone-baited trap was the most efficient and 0.2 m was the best height. In non-source fields with important flights of immigrant female midges, however, yellow water traps could be more efficient than pheromone-baited traps, capturing males almost exclusively. For M. penetrans, the most efficient traps were the sticky and yellow water traps and the best height was 0.6 m. These relative efficiencies of traps and height positions were clearly related to differences in flight behavior between the species and between the sexes.

Monitoring the occurrence of Asian gypsy moth(Lymantria dispar asiatica)with sex pheromone-baited trap in five types of forest stands

Monitoring the occurrence of Asian gypsy moth(Lymantria dispar asiatica)with sex pheromone-baited trap in five types of forest stands

First report of tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), in Botswana

BackgroundThe tomato leaf miner Tuta absoluta (Lepidoptera: Gelechiidae) is an invasive insect pest of tomato and other solanaceous plants which is rapidly expanding its geographic range. It has a highly damaging effect on tomatoes and potential of threatening food production and consequently national food security. Here, we report on the first detection of T. absoluta in Botswana, its consequences on agriculture and food security, and recommend on management strategies. The pest was observed feeding on Solanum lycopersicum L. plants at Genesis farm, Matshelagabedi village in northern Botswana. Following detection, we incubated infected tomato fruits until adult eclosion. External morphology was conducted and confirmed at Botswana International University of Science and Technology (Botswana). Molecular identification and morphological male genitalia were confirmed at Stellenbosch University (South Africa). In addition, we set up some sex-specific pheromone (Tuta optima PH-937-OPTI) at the core detection site and surrounding areas.ResultsMorphological genitalia features of pheromone-baited trap catches confirmed the insect pest was indeed T. absoluta. Molecular analysis also confirmed the morphological identification and thus confirming this first report of T. absoluta in Botswana.ConclusionThis first record of T. absoluta in Botswana is worth reporting to promote coordinated efforts amongst stakeholders, research specialists and extension officers in Botswana and across the southern African region in monitoring and managing the pest.

A Comparative Study on the Effect of Pheromone Baited Traps and Acalypha indica Extract on Leucinodes orbonalis

Botanical insecticides are naturally occurring chemicals extracted from plants. This study aims to analyze the insecticidal activity of bioactive compounds present in the aqueous extract of Acalypha indica and to analyze the efficacy of pheromone baited traps in integrated pest management. In this study, various bioactive compounds present in the aqueous extract of Acalypha indica were analyzed by phytochemical screening and GC-MS analysis. The molecular properties of the compounds identified from GC-MS analysis were screened based on Tice rules using bioinformatics molecular property analysis tools. Out of 8, four compounds namely oleic acid, phytol, flavone and estra-1, 3, 5[10]-trien-17a`-ol strictly follows Tice rules. The aqueous extracts were used for the screening of insecticidal activity against 3rd instar larvae of Leucinodesorbonalis by diet incorporation bioassay. On observation it was revealed that the aqueous extract of Acalypha indica induce antifeedant effect, which was very efficient at 80% concentration. Three pheromone baited traps namely yellow sticky trap, bucket trap and sleeve trap were used to evaluate its efficacy in pest management. From the evaluation, out of three pheromone baited traps, sleeve traps performed statistically better than others, trapping higher population of adult Leucinodes orbonalis. The sticky traps captured the highest number of non-target insects, mostly being ants, flies, and beetles. In bucket trap moderate non-target populations were present. Thus, on the comparative study the preliminary screening shows that Acalypha indica can be used to derive a novel insecticide and pheromone baited sleeve trap shows positive integrated pest management.

Simulation Modeling to Interpret the Captures of Moths in Pheromone-Baited Traps Used for Surveillance of Invasive Species: the Gypsy Moth as a Model Case.

When pheromone traps are used for detection of an invasive pest and then delimitation of its distribution, an unresolved issue is the interpretation of failure to capture any target insects. Is a population present but not detected, a so-called false negative? Using the gypsy moth (Lymantria dispar) as an exemplar, we modeled the probability of males being captured in traps deployed at densities typical for surveillance (1 per 2.6km2 or 1 per mi2) and delimitation (up to 49 per 2.6km2). The simulations used a dynamic wind model generating a turbulent plume structure and varying wind direction, and a behavior model based on the documented maneuvers of gypsy moths during plume acquisition and along-plume navigation. Several strategies of plume acquisition using Correlated Random Walks were compared to ensure that the generated dispersions over three days were not either overly clumped or ranged many km. Virtual moths were released into virtual space with patterns mimicking prior releases of gypsy moth males in Massachusetts at varying distance from a baited trap. In general, capture rates of virtual and real moths at varying trap densities were similar. One application of this approach was to estimate through bootstrapping the probabilities of not detecting populations having densities ranging from 1 to 100 moths per 2.6km2 and using traps that varied from 25 to 100% in their efficiencies of capture. Low-level populations (e.g., 20-30 per 2.6km2) often were not detected with one trap per 2.6km2, especially when traps had low efficiencies.

Evaluation of the Counting Success of Pheromone-Baited Trap with Electronic Control Unit

Pheromone-baited traps are used to monitor bark beetle adult populations for pest management. In the present study, beetles have been counted using a pheromone-baited trap prototype, with electronic control unit. The recording success of their instant date, hour, temperature and humidity parameters have been evaluated. In the tests, 87.1% of the beetles has been counted and recorded. The reliability of the instant parameters has been verified with external equipment. Although the counting success ratios of the tests conducted in dark and under daylight conditions vary in a statistically significant manner, they are close to each other, i.e. 83.7% and 90.2% respectively. A statistically significant difference has not been detected between the counting success of these throwing frequencies, and the counting success ratios vary between 80.7% and 91.8%. When the beetles were thrown by groups of two, three and four in the trap at the same, it has also been found that at least 83.3% of the beetles can be counted successfully in the tests.

Forest tent caterpillar, Malacosoma disstria (Lepidoptera: Lasiocampidae), mate-finding behavior is greatest at intermediate population densities: implications for interpretation of moth capture in pheromone-baited traps

The forest tent caterpillar, Malacosoma disstria Hubner (Lepidoptera: Lasiocampidae) is a native forest defoliator with a broad geographic range in North America. Forest tent caterpillars experience cyclical population changes and at high densities, repeated defoliation can cause reduced tree growth and tree mortality. Pheromone-based monitoring of forest tent caterpillar moths can provide information on spatial and temporal patterns of incipient outbreaks. Pheromone-baited trap capture of male moths correlates to the number of eggs and pupae in a population but this relationship breaks down at high population densities, when moth trap capture declines. The objective of the current study is to understand the mechanisms that reduce trap capture at high population densities. We tested two different hypotheses: 1) at high population densities, male moth orientation to pheromone sources is reduced due to competition for pheromone plumes; and 2) moths from high density populations will be in poor condition and less likely to conduct mate-finding behaviors than moths from low density populations. A field study showed non-linear effects of density on male moth capture in female-baited traps. The number of males captured increased up to an intermediate density level and declined at the highest densities. Field cage studies showed that female moth density affected male moth orientation to female-baited traps, as more males were recaptured at low than high female densities. There was no effect of male density on the proportion of males that oriented to female-baited traps. Moth condition was manipulated by varying larval food quantity. Although feeding regimes affected the moth condition (size), there was no evidence of an effect of condition on mate finding or close range mating behavior. In the field, it is likely that competition for pheromone plumes at high female densities during population outbreaks reduces the efficacy of pheromone-baited monitoring traps.

Efficacy of Pheromone Trapping of the Sweetpotato Weevil (Coleoptera: Brentidae): Based on Dose, Septum Age, Attractive Radius, and Mass Trapping

Pheromone dose, effective trapping distance, and longevity of the rubber septa loaded with sex pheromone of Cylas formicarius (F.) (Coleoptera: Brentidae) were evaluated for their impact on the efficacy of mass trapping of the insect in sweet potato fields in Guam in 2012-2013. The number of adults caught at different distances (10-100 m) was significantly different. Catches declined with increasing release distance from the trap in both downwind and upwind directions. While the maximum radius of attraction of pheromone-baited trap for C. formicarius in the field was 80 m, the effective distance for recapturing marked adults in the pheromone-baited Unitraps was 60 m. Pheromone lures were able to capture adults of C. formicarius after being stored in the laboratory for up to 98 d. The number of catches per trap per week was highest when lures were 0-14- and 15-28-d-old, and longer storage of septa led to a progressive reduction of catches. Pheromone traps baited with 100-μg lures captured significantly more adults compared with those loaded with 10-μg lures. In addition, effectiveness of pheromone trapping on damage to sweet potato was tested at two locations. Number of trapped adults, damage level at different times after trap installation, and yield production were evaluated. The number of C. formicarius adults collected in traps at both locations fluctuated dramatically among sampling dates and peaked on 13 September 2013, after which time the number of captures noticeably declined. This decrease was correlated to the increasing age and depletion of the pheromone lures. Pheromone traps significantly reduced feeding damage caused by weevils (<1 feeding hole per root in treatment; up to 38 feeding holes per root in the control) at both locations. Being consistent with damage levels, sweet potato yields in fields with traps were higher than those in untreated controls. We conclude that pheromone-baited traps are effective in reducing damage due to C. formicarius.

Effects of trap height, location, and spacing on pheromone-baited trap catch efficacy for oriental fruit moths (Lepidoptera: Tortricidae) in a peach orchard

AbstractThe establishment of standardised methods for monitoring the oriental fruit moth Grapholitha molesta (Busck) (Lepidoptera: Tortricidae) requires the identification of factors that significantly affect trap catch efficacy. We examined the effects of trap height, trap location, and inter-trap spacing on trap catches in a conventional peach orchard. Traps were placed at heights of up to 3.0 m above the ground and sets of nine traps were positioned in grids with inter-trap distances of 10–50 m to determine the optimum trap height, location, and spacing. Traps were checked daily over 10 days for males during four periods corresponding to peak moth flight. Moth catches were higher when traps were placed toward the tops (2.5 m) and outside the canopy (3.0 m). Moth catches in traps located upwind and outside tended to be higher than in the central trap for all inter-trap distances. When inter-trap distances were shorter than 30 m, interference between traps occurred. Our results provide an efficient trap distribution for monitoring G. molesta in peach orchards.