Efficacy Of Mating Disruption Research Articles

Mating disruption technology: An innovative tool for managing yellow stem borer (Scirpophaga incertulas Walker) of rice in Indonesia

Yellow stem borer (YSB) of rice, Scirpophaga incertulas Walker, causes significant damage to rice production in Indonesia. YSB management largely depends on insecticide applications and alternative management practices are very few and impractical. Pheromone-mediated mating disruption (MD) is a new way to manage YSB while reducing dependence on conventional insecticides. Pheron™ RSB is an low-density polyethylene (LDPE) MD dispenser, containing 1.25 g of a four-way blended insect sex pheromone components - Z11-Hexadecenal, Z9-Hexadecenal, Z13-Octadecenal, Z9-Octadecenal in a ratio of 75, 8.6, 9.4, and 7 respectively. The objective is to evaluate MD by Pheron™ RSB as a tool for season-long management of YSB. Dispensers were applied at a rate of 20 dispensers/ha in a minimum area of 4 ha. We conducted these trials at 74 locations, non-replicated, across Java, in the wet and dry seasons of 2020–2021 where YSB are endemic and problematic. Efficacy of MD in pheromone foundational practice (PFP) was compared to conventional grower practice (CGP). Trap reduction, a measure of MD was significantly higher (>70%) in PFP as compared to CGP. A major benefit of MD is reduction in damage. Significantly lower damage to rice tillers (40–46%) was seen in PFP compared to CGP. Lower damage in PFP likely protected yield by 0.43 to 0.76 ton/ha compared to CGP. Compared to PFP, CGP required 40–56% higher insecticide applications to manage YSB. Pheron™ RSB provided season-long MD and proved to be a powerful tool for integrated management of YSB.

Pheromone-mediated mating disruption of the European grain moth Nemapogon granellus in ham factories

Nemapogon granellus is a lepidopteran species that can cause significant damage to stored animal products such as meats, sausages and cheeses. In the warehouses where such products are stored, pheromone-based control approaches can avoid or reduce insecticide chemical treatments and be more effective than traditional control methods. This study aimed to evaluate the effectiveness of mating disruption (MD) techniques to control N. granellus populations in ham factories. Trials were conducted in two factories located in Northern Italy. In both locations two warehouses were selected: a warehouse test where dispensers, loaded with 10 mg of N. granellus pheromone, were deployed at a density ranging from 1 unit/22.5 m3 (factory A) to 1 unit/25 m3 (factory B), and a control warehouse left untreated. To assess the mating disruption efficacy, the reduction of the number of mated females in water traps, placed in control and treated warehouses, was used as main parameter. The results indicated a substantial reduction in mated females in the treated warehouses in comparison with control warehouses in both the sites of experiments. In detail, the total number of mated females sampled in water traps was above 90% in control warehouses, in warehouses treated with MD technique this percentage was below 50%. In addition, a “trap shutdown” effect was recorded in MD treated warehouses of both factories. These findings suggest that mating disruption is a promising technique that can be positively applied in the integrated pest management of N. granellus in ham factories.

Adoption of Amyelois transitella (navel orangeworm) monitoring and management practices across California tree nut crops

Abstract In California, the most significant insect pest of almonds and pistachios is the navel orangeworm, Amyelois transitella (Walker) and is a pest of walnuts. This pest attacks the nuts and infestation is associated with aflatoxin contamination. While there are multiple integrated pest management (IPM) practices available, anecdotal evidence suggests that not all tools are equally utilized. To understand current industry practices and barriers to adoption, the authors surveyed tree nut growers and industry professionals across 7 University of California Cooperative Extension meetings in California’s Central Valley. Findings indicate that as managed acres decreased, participants were less likely to report using as many IPM tools, and pest control advisers reported higher use of multiple practices compared to orchard owners and managers. Key barriers to adoption varied by practice and included high economic costs, low labor availability, environmental conditions, and/or timing constraints. Many respondents were skeptical of the efficacy of mating disruption, a relatively new strategy compared to other IPM tools. Finally, a cluster analysis identified thirteen aggregate grower profiles. Groups primarily differed in their use of monitoring practices, although some groups were also less likely to use sanitation or pesticides. Two groups were distinguished as “early adopters” through their use of mating disruption and/or ovibait traps. These findings document variability in adoption of IPM practices for A. transitella in tree nuts. Identification of the primary barriers and constraints for specific grower groups will inform research and extension efforts to further promote adoption of key IPM strategies.

Perception of Heterospecific Sex Pheromone Causes Less Effective Mating Disruption in the Beet Semilooper, Autographa nigrisigna (Lepidoptera: Noctuidae).

Confuser® V is a pheromone-based mating disruptant designed to reduce damage caused by seven species of moth pests, including the beet semilooper, Autographa nigrisigna (Lepidoptera: Noctuidae). Eggs and larvae of A. nigrisigna are often found in fields treated with Confuser® V, suggesting that some components in the Confuser® V blend may have adverse effects on the efficacy of mating disruption of this species. Therefore, we examined whether A. nigrisigna perceives heterospecific pheromone components in the Confuser® V blend and delineated the roles of these components with respect to attraction and communication disruption. We found that several heterospecific pheromone components in the Confuser® V blend were perceived by male A. nigrisigna, and the addition of these components to the pheromone blend of A. nigrisigna reduced the attraction of males in the field, and tended to reduce the efficacy of mating disruption in cage bioassays.

MANAGEMENT OF PINK BOLLWORM WITH MATING DISRUPTION TECHNIQUE IN SMALLAR PLOTS OF COTTON

Pink bollworm, Pectinophora gossypiella is the most damaging pest of cotton irrespective of Bt and non Bt. The damage of the Pink bollworm has increased in Pakistan since 2015 to till now. The main purpose to conduct this study was the evaluation of mating Disruptor’s efficiency against Pink bollworm in smaller plots of cotton. This experiment was conducted at farmer’s field at Bomb more Jalalpur pirwala district Multan on cotton season 2018. The PB-ropes were installed in 1st treatment at the rate of 150 ropes/ acre while the PB-ropes were applied in the 2nd treatment at the rate of 200 ropes/acre and the third treatment was kept as control. The gossyplure baited traps were installed in the cotton at flowering stage in 1st week of August The gossyplure baited traps were installed in the cotton field to monitor the activity of Pink bollworm moth catches in both treatments and control block. It was also observed that the mating disruption efficacy of PB-Ropes remained up to three months. The significant decrease of % damage in green bolls was observed in the plot treated with PB-Ropes @ 200 ropes/ acre (4.73±0.57b) following 150 ropes treated plot (4.73±0.57 b) as compared to control block (31.04±2.42a). The number of moth catches was reduced in the plot treated with PB-Ropes @ 200 ropes /acre(3.40±0.34b) following 150 ropes treated plot (4.64 ± 0.37b) as compared to control block(40.47 ± 1.67a) .The results were further confirmed by % infestation in leftover bolls of the plot treated with PB-Ropes @ 200 ropes / acre (14.00 ± 0.57 b) following plot treated with PBRopes @ 150 ropes / acre (20.33 ± 0.88 b) as compared to control plot (63.00 ± 2.08 a).

MANAGEMENT OF PINK BOLLWORM WITH MATING DISRUPTION TECHNIQUE IN SMALLAR PLOTS OF COTTON

Pink bollworm, Pectinophora gossypiella is the most damaging pest of cotton irrespective of Bt and non Bt. The damage of the Pink bollworm has increased in Pakistan since 2015 to till now. The main purpose to conduct this study was the evaluation of mating Disruptor’s efficiency against Pink bollworm in smaller plots of cotton. This experiment was conducted at farmer’s field at Bomb more Jalalpur pirwala district Multan on cotton season 2018. The PB-ropes were installed in 1st treatment at the rate of 150 ropes/ acre while the PB-ropes were applied in the 2nd treatment at the rate of 200 ropes/acre and the third treatment was kept as control. The gossyplure baited traps were installed in the cotton at flowering stage in 1st week of August The gossyplure baited traps were installed in the cotton field to monitor the activity of Pink bollworm moth catches in both treatments and control block. It was also observed that the mating disruption efficacy of PB-Ropes remained up to three months. The significant decrease of % damage in green bolls was observed in the plot treated with PB-Ropes @ 200 ropes/ acre (4.73±0.57b) following 150 ropes treated plot (4.73±0.57 b) as compared to control block (31.04±2.42a). The number of moth catches was reduced in the plot treated with PB-Ropes @ 200 ropes /acre(3.40±0.34b) following 150 ropes treated plot (4.64 ± 0.37b) as compared to control block(40.47 ± 1.67a) .The results were further confirmed by % infestation in leftover bolls of the plot treated with PB-Ropes @ 200 ropes / acre (14.00 ± 0.57 b) following plot treated with PBRopes @ 150 ropes / acre (20.33 ± 0.88 b) as compared to control plot (63.00 ± 2.08 a).

Drones That Deliver: Pheromone-Based Mating Disruption Deployed via Uncrewed Aerial Vehicles in U.S. Cranberries.

Cranberry fruitworm (Acrobasis vaccinii Riley (Lepidoptera: Pyralidae)) and blackheaded fireworm (Rhopobota naevana Hubner (Lepidoptera: Tortricidae)) threaten cranberry production annually by causing significant fruit damage. Up to four pesticide applications are made each year to control these insects, which are costly to producers and elevate pesticide residues in fruit. Pheromone-based mating disruption technology can provide control of these pests in cranberry production, with the potential to minimize, or eliminate, pesticide applications. In 2016, an uncrewed aerial vehicle (UAV) was investigated to apply a thick paraffin emulsion containing insect sex pheromones. Traditional agricultural equipment is not capable of applying the paraffin emulsion to cranberry beds due to the product's viscous, paste-like consistency. The first objective of this study was to retrofit an UAV (octocopter) with a novel extrusion device that had been engineered to deliver the pheromone-loaded paraffin at regular intervals during flight. The second objective was to confirm adequate distribution of the pheromones by measuring the mating disruption efficacy by monitoring male moth trap catches. The UAV was able to fly autonomously along a prescribed itinerary, deploying the paraffin product uniformly; however, the increased mass of the retrofitted UAV limited flight times to ~12 min. The number of male cranberry fruitworm and blackheaded fireworm moths caught in lure-baited traps were reduced in the paraffin-treated beds compared with untreated beds, indicating adequate distribution of the pheromones. The UAV-applied pheromones concept could be developed into a production scale application method in the future, although issues of battery life and lifting capacity will need to be resolved.

Parthenogenesis in UK field populations of the tomato leaf miner, Tuta absoluta, exposed to the mating disruptor Isonet T.

The tomato leafminer, Tuta absoluta is a damaging pest of tomato crops worldwide. In the UK T. absoluta is controlled using an integrated pest management (IPM) strategy that includes pheromone-based mating disruption. However, some growers have reported a loss of efficacy of this technology, and there are concerns that T. absoluta may evolve resistance via changes in its capacity to reproduce asexually. In this study we investigated the reproductive capacity of virgin populations of T. absoluta collected from a UK glasshouse before (EVH2016) and after (EVH2019) the introduction of the mating disrupter Isonet T. In line with earlier reports, we demonstrate that UK populations of T. absoluta can reproduce parthenogenetically, and observed a small but significant increase in the rate of parthenogenesis associated with the use of Isonet T. Marked differences in several other life history traits associated with reproduction were also observed between the two virgin populations, with the EVH2019 strain producing fewer eggs, a delayed onset of egg laying and increased lifespan. The low rate of parthenogenetic reproduction seen in this study is unlikely to result in loss of efficacy of mating disruption. However, the observed changes in longevity and egg laying may allow T. absoluta to persist for longer within the crop, and, together with the increased rate of parthenogenesis, may reflect selection from the use of Isonet T. Thus, regular monitoring of the reproductive capacity of UK populations should be conducted, and mating disruption used only as part of IPM to avoid the emergence of resistance. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Individual and Additive Effects of Insecticide and Mating Disruption in Integrated Management of Navel Orangeworm in Almonds.

Simple SummaryMating disruption is an increasingly important part of pest management for the navel orangeworm Amyelois transitella. Industry groups have long supported mating disruption research and development with the divergent objectives of both minimizing damage from this key pest and reducing insecticide used on these crops. It is therefore important to know whether the benefits of mating disruption and insecticide are additive or, alternatively, if using both together provides no additional benefit over either alone. Ten years of data from research trials in a large commercial almond orchard found that the benefits of mating disruption are generally additive with lower damage if both are used together than either alone. Substantial year-to-year variability in navel orangeworm damage was also evident, even with stringent management. These findings indicate that the combination of mating disruption and insecticide can reduce the impact of navel orangeworm damage on the almond industry. Further improvements in monitoring and predictions of navel orangeworm abundance and damage are necessary for mating disruption to effectively contribute to the industry goal of reduction of insecticide use by 25%.Damage from Amyelois transitella, a key pest of almonds in California, is managed by destruction of overwintering hosts, timely harvest, and insecticides. Mating disruption has been an increasingly frequent addition to these management tools. Efficacy of mating disruption for control of navel orangeworm damage has been demonstrated in experiments that included control plots not treated with either mating disruption or insecticide. However, the navel orangeworm flies much farther than many orchard pests, so large plots of an expensive crop are required for such research. A large almond orchard was subdivided into replicate blocks of 96 to 224 ha and used to compare harvest damage from navel orangeworm in almonds treated with both mating disruption and insecticide, or with either alone. Regression of navel orangeworm damage in researcher-collected harvest samples from the interior and center of management blocks on damage in huller samples found good correlation for both and supported previous assumptions that huller samples underreport navel orangeworm damage. Blocks treated with both mating disruption and insecticide had lower damage than those treated with either alone in 9 of the 10 years examined. Use of insecticide had a stronger impact than doubling the dispenser rate from 2.5 to 5 per ha, and long-term comparisons of relative navel orangeworm damage to earlier- and later-harvested varieties revealed greater variation than previously demonstrated. These findings are an economically important confirmation of trade-offs in economic management of this critical pest. Additional monitoring tools and research tactics will be necessary to fulfill the potential of mating disruption to reduce insecticide use for navel orangeworm.

Control of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in open field tomato crops using the mating disruption technique

This study was conducted in Meram district of Konya province (Turkey) in 2018 and 2019 to evaluate the efficacy of mating disruption against the tomato leafminer, Tuta absoluta in an open-field tomato growing area. Three pheromone-treated fields and three control fields were used to evaluate the effectiveness of mating disruption in both years. In pheromone-treated fields, mating disruption pheromone was applied once at a rate of 2500 g/ha with a caulking gun. In control fields, only pheromone traps were hung for monitoring and comparing the pest population. Male captures in monitoring pheromone traps and infestation rates of tomato plants by T. absoluta were recorded weekly. The mean number of males captured in the traps per week in pheromone-treated fields in 2018 and 2019 was 120.86 ± 16.82 and 69.90 ± 15.70, respectively. In control fields, the mean number of males captured in the traps per week in 2018 and 2019 was 299.73 ± 16.82 and 230.75 ± 15.70, respectively. The mean percentage of infestation of the pest was 4.40 ± 0.56% in pheromone-treated fields, while it was 11.80 ± 0.56% in control fields in 2018. In 2019, the mean percentage of infestation of the pest was recorded in pheromone-treated and control fields as 1.88 ± 0.52% and 7.39 ± 0.52%, respectively. As a result of the study, it was determined that the mating disruption application against T. absoluta was successful in all three pheromone-treated fields when compared to control fields in both years. This technique was tested for the first time against the tomato leafminer in Turkey with this project.

Comparison of Mating Disruption and Insecticide Application for Control of Peachtree Borer and Lesser Peachtree Borer (Lepidoptera: Sesiidae) in Peach.

Simple SummaryThe peachtree borer and lesser peachtree borer are destructive insect pests of peach and other stone fruit. Damage is caused by larval feeding on the vascular cambium, which reduces tree health and vigor and can lead to tree death. The traditional method to control these pests is with directed trunk sprays of the organophosphate insecticide, chlorpyrifos. However, the ongoing review of pesticide tolerances mandated by the United States Environmental Protection Agency (US-EPA) makes the option of future long-term use of chlorpyrifos uncertain. Mating disruption is an alternative method of control that uses synthetic sex pheromones to disrupt male mate-finding behavior and prevent mating. We conducted field studies to compare the efficacy of mating disruption and application of chlorpyrifos insecticide for control of this pest complex. Although our data indicated that mating disruption can provide growers with an effective non-chemical alternative to chlorpyrifos trunk sprays, several variables may affect its long-term success in West Virginia peach orchards; most notably the presence of high population densities of the pest species, problems with maintaining adequate pheromone coverage in orchards, and the need for area-wide implementation.The peachtree borer, Synanthedon exitiosa, and lesser peachtree borer, S. pictipes, are economically important indirect pests of peach in West Virginia. The purpose of this 3-year study was to compare the efficacy of mating disruption and post-harvest trunk sprays of chlorpyrifos insecticide for control of this pest complex in a commercial peach orchard. Overall, Isomate PTB-Dual disruption dispensers applied at a rate of 371/ha significantly disrupted the male mate-finding behavior of S. exitiosa and S. pictipes. In addition, the infestation of peach trees by S. exitiosa larvae did not vary significantly between mating disruption and insecticide treated plots. Hot-spot maps of S. exitiosa infestation showed significant spatial clusters of infestation predominately near the perimeter of all orchard plots, or where trees were missing within and/or between rows. The generation of standard deviational ellipses revelated that the location of S. exitiosa infestations in orchard plots remained relatively constant between years, and were generally oriented in a north and easterly direction, which coincided with the prevailing wind direction. Although our data indicated that mating disruption can provide growers with an effective non-chemical alternative to chlorpyrifos trunk sprays, several variables may affect its long-term success in West Virginia peach orchards; most notably the presence of high population densities, problems with maintaining adequate pheromone coverage, and the need for area-wide implementation.

Mating Disruption of Helicoverpa armigera (Lepidoptera: Noctuidae) on Processing Tomato: First Applications in Northern Italy.

Helicoverpa armigera is a polyphagous and globally distributed pest. In Italy, this species causes severe damage on processing tomato. We compared the efficacy of mating disruption with a standard integrated pest management strategy (IPM) in a two-year experiment carried out in Northern Italy. Mating disruption registered a very high suppression of male captures (>95%) in both growing seasons. Geostatistical analysis of trap catches was shown to be a useful tool to estimate the efficacy of the technique through representation of the spatial pattern of captures. Lower fruit damage was recorded in mating disruption than in the untreated control plots, with a variable efficacy depending on season and sampling date. Mating disruption showed a higher efficacy than standard IPM in controlling H. armigera infestation in the second season experiment. Mating disruption showed the potential to optimize the H. armigera control. Geostatistical maps were suitable to draw the pheromone drift out of the pheromone-treated area in order to evaluate the efficacy of the technique and to detect the weak points in a pheromone treated field. Mating disruption and standard IPM against H. armigera were demonstrated to be only partially effective in comparison with the untreated plots because both strategies were not able to fully avoid fruit damage.

Efficacy of mating disruption compared with chemical insecticides for controlling Tuta absoluta (Lepidoptera: Gelechiidae) in Kuwait

The efficacy of mating disruption with Isonet®-T at the rate of 30, 45 or 60 g a.i. ha –1 of sex pheromone to control Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in greenhouse tomato crops was compared with conventional insecticides (flubendiamide, 60 mg L–1 and azadirachtin, 3 g L–1) in winter and summer. In both trials, significantly fewer moths were captured in mating disruption and insecticide-treated plots compared with the control. Differences in male captures between plots disrupted with 60 g a.i. ha –1 of sex pheromone and the insecticide-treated was significant only in summer. In plots disrupted with 60 g a.i. ha –1 of sex pheromone, male captures were significantly reduced by 90% in both trials. No significant differences were found in foliage and fruit damage between plots disrupted with 60 g a.i. ha –1 of sex pheromone and the insecticide-treated. The lower pheromone doses did not achieve a reduction in moth population, foliage, or fruit damage compared with the high pheromone dose or the insecticide treatments. The results suggest that mating disruption applied at high doses could be as effective as insecticides in managing T. absoluta, and could serve as a key component of an IPM program for the pest.

Simultaneous mating disruption of two Grapholita species in apple orchards

Abstract Two Grapholita species (G. molesta and G. dimorpha) cause serious losses in apple production by means of direct fruit damage and destruction. These two congeners occurred at similar seasons in the same orchards. Furthermore, the two species occurred in similar population sizes in apple orchards, though G. molesta occurred much more in total occurrence density than did G. dimorpha in a pear orchard. The two species share two major sex pheromone components, (Z)-8-dodecenyl acetate (Z8-12:Ac) and (E)-8-dodecenyl acetate (E8-12:Ac), but differ with regard to the relative mixture ratio necessary to create conditions of maximal attraction. To develop a simultaneous mating disruption (SMD), a mass ratio of 95:5 of Z8-12:Ac and E8-12:Ac was selected due to its high cross-calling activity and subsequent high mating disruption against both species. When the mixture was applied to orchards, it resulted in significant mating disruption against both species. However, mating disruption efficacy was slightly higher in G. dimorpha than in G. molesta. Application dose and dispenser type affected efficacy duration of SMD. In addition, the high density occurrence of G. molesta significantly reduced the SMD efficacy. Using a wax-type of dispenser, an application of SMD in 100 g per hectare dispersed in early spring recorded >90% mating disruption efficacy through the entire growing season against both Grapholita species.

Relationship between efficacy of mating disruption and gypsy moth density

ABSTRACTMating disruption tactics involve the deployment of pheromones to interfere with mate finding behaviors in insect populations. This management strategy is the dominant one used against expanding gypsy moth populations in the United States, and historically it has been assumed to be most effective against low-density populations. Operationally, mating disruption is used in areas where the season-long trap catch is <30 males/trap, however the maximum population density at which mating disruption is effective remains unknown. We analysed historical gypsy moth mating disruption treatment data from 2000 to 2010, and used this information to guide the mating disruption field studies conducted from 2012 to 2015 against artificially-created populations of various densities, from 0 to 116 males/trap/day. We observed that mating disruption tactics at a dose of 15 g AI/ha were effective against gypsy moth populations with a season-long trap catch of at least 115 males/trap. This research highlights the utility of mating disruption in higher gypsy moth densities than what is currently recommended in management programs.

Identification of a floral-derived kairomone for currant clearwing, Synanthedon tipuliformis

The currant clearwing Synanthedon tipuliformis (Clerck) (Sesiidae) is a worldwide pest of black currants, Ribes nigrum. This moth has been observed to feed on nectar of inflorescences of Canada thistles, Cirsium arvense (L.) Scop. This work was undertaken to identify floral compound(s) produced by Canada thistles inflorescences that mediate the response of the currant clearwing. Floral volatiles were collected during the day and analysed by coupled gas chromatography/electroantennographic detection (GC/EAD) and gas chromatography/mass spectrometry (GC/MS). Three compounds consistently elicited EAD response from moth antennae and were identified by GC/MS as phenylacetaldehyde, methyl salicylate and dimethyl salicylate. When the compounds were tested individually or in various combinations in field trapping experiments, a 3-component blend attracted the largest number of female and male currant clearwings. Subsequent field trapping experiments were conducted to determine the optimal attraction dose for the ternary blend using three loadings of 1, 10 and 100 mg loaded into a polyethylene sachet. The highest catches were in traps baited with the 100 mg loading. In all trials, males and mated females were caught in significant numbers, while very low numbers of virgin females were found in the traps. In recent years the efficacy of mating disruption against currant clearwing has been reported as declining. The new kairomone blend identified in this study can be used with the sex pheromone to provide an effective control option for this important pest.

Co-application of microencapsulated pear ester and codlemone for mating disruption of Cydia pomonella

Studies were conducted in two apple orchards in 2009 and 2010 to examine whether the efficacy of mating disruption can be improved by co-applying microencapsulated (MEC) pear ester (DA-MEC) and codlemone (Ph-MEC) in comparison to DA-MEC and Ph-MEC treatments alone. Combined applications were made at a rate of 5 g a.i ha−1 DA-MEC + 25 g a.i ha−1 Ph-MEC in HV (635 L water ha−1) and ULV (40 L water ha−1) sprays. Moth catches were monitored weekly with delta-style traps containing 3 mg each of codlemone and pear ester. Moths in DA-combo traps were sexed and females were dissected to determine mating status. Codling moth catches did not differ significantly between the ULV and HV sprays of DA-MEC + Ph-MEC. The combinational MEC-treatments applied in both spray volume maintained good trap shutdown, each averaging 85 % reduction in moth capture over distant control orchards. While DA-MEC and Ph-MEC treatments alone disrupted male codling moth orientation to traps by 43 and 61 %, respectively. In the DA-MEC, Ph-MEC and combinational blocks, DA-combo traps caught a lower percentage (9–14 %) of female moths than those placed in both untreated and insecticide-treated blocks. In July and September, fruit damage was evaluated by visually inspecting a total of 1,200 randomly chosen fruits per orchard. Depending on the spray volume used, the combined MEC sprays reduced the number of fruits infested with larvae by 85–93 % compared with untreated control. In conclusion, DA-MEC can effectively augment pheromone mating disruption and offers additional control option for integrated pest management programmes.

Assessment of SPLAT formulations to control Grapholita molesta (Lepidoptera: Tortricidae) in a Brazilian apple orchard

Mating disruption is a technique that uses synthetic copies of sex pheromones to control insect pests. We aimed to control Oriental fruit moth (OFM) Grapholita molesta (Busck) (Lepidoptera: Tortricidae) with formulations of SPLAT Grafo (SG) and SPLAT Grafo Attract and Kill (SGAK) in small (1 ha) apple (Malus domestica Borkh.) orchards. Our experiment was conducted in a commercial orchard with 'Gala' trees (spacing 1.5 x 4.5 m) in Vacaria, Rio Grande do Sul State, Brazil. We evaluated the effect of four treatments on G. molesta population densities: a) SG at 1 kg ha-1 (300 point sources of 3.3 g each), b) SGAK at 1 kg ha-1 (1000 point sources of 1 g each), c) insecticides as recommended by Integrated Apple Production (IAP), and d) untreated control (no treatment). Specialized Pheromone and Lure Application Technology (SPLAT) treatments were applied on 1 August 2004 and reapplied after 120 d (1 December 2004). The treatment effect was evaluated by weekly counts of males captured in Delta traps baited with commercial synthetic sex pheromone lures (eight traps per treatment). We assessed fruit damage caused by G. molesta in eight replicates of 200 fruits each on 26 October, 30 November 2004, and 5 and 31 January 2005. Applying 1 kg ha-1 of SG and SGAK in August and December 2004 significantly reduced the number of male moths caught in Delta traps. Damage to fruits at harvest, however, did not differ significantly from the control. This indicates a decline in the efficacy of mating disruption when SG and SGAK are used to protect small areas (1 ha) under high Oriental fruit moth pressure.

Mating disruption of pea moth (Cydia nigricana) in organic peas (Pisum sativum)

We appraised mating disruption (MD) to control pea moth, Cydia nigricana (Fabricius) (Lepidoptera: Tortricidae), by assessing male attraction to monitor traps, larval pod infestation, and larval age structure in pheromone-treated and untreated grain pea fields [Pisum sativum L. (Fabaceae)], over a 5-year period. Cellulose pheromone dispensers were manually attached to the top shoots of pea plants and released 540 mg ha−1 day−1 synthetic pheromone E8,E10-dodecadien-1-yl acetate in a first test series (2000–2001) and ca. 4 200 mg pheromone ha−1 day−1 in a second series (2004–2006). The dispensers had a half-life of about 30 days. Although male attraction to pheromone monitoring traps was largely suppressed at the edges and within MD fields in both test series, MD treatments did not reduce pod infestation in the open field in 2000 and 2001. In the 2004–2006 series, larval damage reduction was achieved in the majority of the trials but overall MD efficacy in the open field was only 61% and not significant. In contrast, in field cages placed within the experimental sites and supplied with unmated pea moths, MD control was consistently high and significant. There were no obvious differences in the larval age distribution in all MD and control treatments, suggesting that infestations started and developed further similarly. As a univoltine species, C. nigricana larvae stay in the soil of pea fields for hibernation and pupate. The following year, emerging adults disperse and fly to the closest pea crop. Combined emergence site and pea crop treatments were conducted over 2 years to include this early migration phase of C. nigricana adults. However, the emergence site treatments did not enhance MD-control efficacy. We conclude that mating activity was only prevented in cage tests, whereas substantial mating occurred during the transit phase outside the pheromone-treated fields either within non-crop vegetation and/or at the edges of pheromone-treated pea fields orientated upwind. Thus, resulting gravid female entry can be regarded as the major constraint to reliable MD control.

Field Assessment of Female Mating Success Based on the Presence—Absence of Spermatophore: a Case Study with Spruce Budworm, Choristoneura fumiferana

The mating success of female spruce budworms was evaluated using the presence—absence of spermatophore in genitalia. Sampling was conducted in the 1970s in Atlantic Canada at 21 locations/years characterized by high budworm densities. More than 99.8% of in-flight females (captured at light or malaise traps) and migrant females (collected while ascending above tree canopies or in the airspace) were mated, which may reflect physiological constraints restricting flight in gravid females. About 85% of resident females (collected using sweep nets or by fogging trees with insecticide) were mated; mating success was low among young females collected early in the season and increased over time to reach a level similar (98%) to that of females that died from natural causes. These findings highlight the importance of unbiased estimates of mating success to evaluate the efficacy of mating disruption and the role of mate-encounter Allee effects on population dynamics.