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.     

Comparison of a sprayable pheromone formulation and two hand-applied pheromone dispensers foruse in the integrated control of oriental fruit moth (Lepidoptera: Tortricidae)

The efficacy of integrated programs using a sprayable pheromone formulation or one of two hand-applied pheromone dispensers, and a conventional oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae) control program, was compared using 4-5-ha blocks of peach orchard at three Niagara Peninsula farms during 2000-2002. In the integrated programs, chlorpyrifos and mating disruption with 3M Sprayable Pheromone, Isomate OFM Rosso, or Rak 5 hand-applied dispensers were used to control first-generation larvae, and mating disruption alone was used to control second- and third-generation larvae. In the conventional program, chlorpyrifos was used to control first-generation larvae, and pyrethroid insecticides were used to control larvae of the later generations. All programs were effective at maintaining fruit infestation by G. molesta below the industry tolerance level of 1%. An integrated program using sprayable pheromone required the use of more supplementary insecticide applications to control second- and third-generation larvae than a program using hand-applied dispensers. The elimination of insecticide sprays from integrated program blocks did not result in an increase in damage by plant bugs, Lygus spp. (Hemiptera: Miridae) or by the plum curculio, Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae).     

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.     

Evaluation of extended-season mating disruption of the Oriental fruit moth Grapholita molesta (Busck) (Lep., Tortricidae) in apples

Abstract:  Oriental fruit moth Grapholita molesta (Busck) (Lep., Tortricidae) has recently become a key pest of apples throughout the eastern USA. Pheromone-mediated mating disruption of Oriental fruit moth was successfully used in North Carolina apple orchards in the past few years. However, low levels of late-season fruit damage occurred in some orchards treated in late May with hand-applied pheromone dispensers because of inadequate dispenser longevity. To investigate alternative pheromone application schedules for extended mating disruption control, the following pheromone treatments were compared with conventional insecticides in Henderson County (NC) in 2002: late May application of hand-applied dispensers; late June application of hand-applied dispensers; late May application of hand-applied dispensers supplemented with a late August application of sprayable pheromone dispensers; late May application of hand-applied dispensers which have a longer activity period; and conventional insecticides as a control. All treatments were sprayed with an insecticide at petal fall in late April for thinning and for control of the first generation Oriental fruit moth adults. Pheromone trap catches were significantly reduced in all mating disruption blocks compared with conventional insecticide blocks. Among pheromone treatments, the highest trap captures were recorded in the delayed hand-applied dispenser treatment in June before treatment. However, the mean percentage fruit damage did not vary with timing of application of hand-applied dispensers and the type of pheromone dispenser used. Clearly, the combination of each mating disruption treatment with insecticide application against first generation Oriental fruit moth was as effective as the conventional insecticide treatment under moderate population pressure.     

Comparison of efficacy of programs using insecticide and insecticide plus mating disruption for controlling the obliquebanded leafroller in apple (Lepidoptera: Tortricidae)

The relative efficacy of an insecticide program and an insecticide plus mating disruption program using a sprayable pheromone formulation or a hand-applied pheromone dispenser was compared for control of the obliquebanded leafroller, Choristoneura rosaceana (Harris) at three commercial apple farms in a production area along the north shore of Lake Ontario, Canada, during 2000, 2001, and 2002. The average rate of disruption ranged from 50 to 80% in blocks of orchard treated with sprayable pheromone and from 84 to 98% in blocks treated with the hand-applied dispenser. The average proportion of shoots with larval feeding injury ranged from 0.002 to 0.09, 0.001 to 0.09, and 0.005 to 0.13 in the insecticide, insecticide plus sprayable pheromone, and insecticide plus hand-applied dispenser treatments, respectively, during the 3-yr study. The percentage of fruit with damage caused by spring, summer and overwintering larvae ranged from 0.03 to 0.06, 0.01 to 0.02, and 0.01 to 0.03 in the insecticide, insecticide plus sprayable pheromone, and insecticide plus hand-applied dispenser treatments, respectively. The addition of sex pheromone-mediated mating disruption to a conventional, insecticide-based program did not provide additional control of C. rosaceana feeding injury to shoots or fruit. The possible reasons for the failure of mating disruption to provide additional control are discussed.     

Effects of SPLAT® GM sprayable pheromone formulation on gypsy moth mating success

Several integrated pest management programs rely on the use of mating disruption tactics to control insect pests. Some programs specifically target non‐native species, such as the gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae). We evaluated SPLAT^® GM, a new sprayable formulation of the gypsy moth sex pheromone disparlure, for its ability to disrupt gypsy moth mating. The study was conducted in 2006, 2007, and 2008 in forested areas in Virginia, USA. Mating success of gypsy moth females was reduced by >99% and male moth catches in pheromone‐baited traps by >90%, in plots treated with SPLAT^® GM at dosages ranging from 15 to 75 g of active ingredient (a.i.) ha^?1. Dosage‐response tests conducted in 2008 indicated that SPLAT^® GM applied at a dosage of 7.5 g a.i. ha^?1 was as effective as a 15 g a.i. ha^?1 dosage.     

Examining disruption of pheromone communication in Choristoneura rosaceana and Pandemis limitata using microencapsulated (Z)-11-tetradecenyl acetate applied in a laboratory flight tunnel

Pheromone‐based mating disruption of lepidopteran pests (Tortricidae) of pome fruits using hand‐applied dispensing systems has become standard management practice for many producers in western North America. Sprayable microencapsulated (MEC) pheromone formulations that enable the application of pheromone controls with other orchard sprays and assist in the development of multispecies mating‐disruption systems are currently under development. Responses of male Choristoneura rosaceana (Harris) and Pandemis limitata (Robinson) (Lepidoptera: Tortricidae) to calling females in clean air, and air treated with their major pheromone component (Z)‐11‐tetradecenyl acetate (Z11‐14:OAc), released from a 3M sprayable pheromone formulation containing proprietary 3M Phase I microcapsules, applied at doses of 1, 10, and 100 mg of active ingredient (ai) m^?2 to the upwind end of a flight tunnel (equivalent to field rates of 10, 100, and 1000 g ai ha^?1) were compared in laboratory flight tunnels. In both species, disorientation was found to be dose‐dependent, because relative to male orientation to calling females in clean air, the orientation of male P. limitata was disrupted 23.3, 46.3, and 71.3%, and orientation by male C. rosaceana was disrupted 31.6, 37.7, and 45.8% by treatment doses of 1, 10, and 100 mg m^?2, respectively. Latency of male responses to calling females in a background of Z11‐14:OAc relative to responses in clean air was also dose‐dependent. Albeit short, the disruption lasted 26, 74, and 218 h in P. limitata and 30, 54, and 174 h in C. rosaceana at each application rate, respectively. Disruption by pheromone treatment was greater in P. limitata than in C. rosaceana. This difference may be correlated with species’ differences in the pheromone release rates of females. Mechanisms of disruption invoked by this 3M MEC pheromone formulation are discussed in relation to issues of its longevity and observed differences in the effects against the two species. It appears possible to evaluate relative activity of MEC pheromones in a laboratory setting which may aid in development of new formulations for mating disruption.     

Sprayable microencapsulated sex pheromone formulation for mating disruption of oriental fruit moth (Lepidoptera: Tortricidae) in Australian peach and pear orchards

Areawide mating disruption treatments have been effective in controlling infestation of oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), in Australian pome and stone fruit orchards. Although successful, the areawide mating disruption program has been an expensive approach by using hand-applied Isomate dispensers. Sprayable microencapsulated (MEC) pheromone formulations that can be applied with standard spray equipment could substantially reduce the cost of application. Field trials conducted during two consecutive seasons (2002-2004) demonstrated that monthly applications of MEC-OFM phase V (3M Canada, London, Ontario, Canada) at a rate of 125 ml/ha (37.1 g [AI]/ha) in replicated 2-ha blocks of both peaches and pears reduced oriental fruit moth shoot tip and fruit damage as effectively as a single application of Isomate OFM Rosso hand-applied dispensers (500 dispensers per ha) and as or more effectively than standard broad-spectrum insecticide sprays. Fruit protection was achieved despite high oriental fruit moth population densities in both crops as measured by moth catches in terpinyl acetate food and pheromone traps. Similar numbers of oriental fruit moths were captured among all treatments in food traps but captures of males in pheromone traps were disrupted (96-99%) in pheromone-treated blocks relative to controls. The results of this study suggest that microencapsulated formulations of pheromone could be effectively used in areawide mating disruption programs for oriental fruit moth in Australia as a cost-saving alternative to reservoir-style dispensers requiring labor-intensive hand application.     

Comparison of pheromone-mediated mating disruption and conventional insecticides for management of tufted apple bud moth (Lepidoptera: Tortricidae)

Large-plot studies were used to compare pheromone-mediated mating disruption and conventional insecticide applications for management of tufted apple bud moth, Platynota idaeusalis (Walker), in North Carolina in 1993 and 1994. Pheromone trap catches were reduced in mating disruption blocks, and traps placed in the lower stratum of the canopy had a higher level of trap capture reduction compared with traps placed in the upper stratum. First-generation tufted apple bud moth exposure to either pheromones for mating disruption or insecticides affected second generation pheromone trap catches in the lower and upper canopy. More second generation male moths were caught in pheromone traps placed in the upper compared with the lower canopy in blocks treated with pheromones for mating disruption during the first generation, whereas the opposite was true in blocks treated with insecticides during the first generation. Despite reduced trap catches in pheromone-treated blocks, egg mass densities were not reduced in these blocks compared with insecticide-treated blocks. Furthermore, fruit damage was not significantly different between mating disruption blocks and conventionally treated blocks in orchards with relatively low populations of tufted apple bud moth, but damage was greater in mating disruption blocks in orchards with higher moth densities.     

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.     

Mating disruption for the control of the olive moth, Prays oleae (Bern) (Lep., Yponomeutidae) with the ajor sex pheromone component

Abstract: Mating disruption to control the olive moth Prays oleae (Bern) was tested from 1992 to 1996 in olive groves in Greece. The major sex pheromone component (Z)-7-tetradecenal was formulated in β-cyclodextrin (β-CD) and polyvinyl chloride (PVC) polymers. Pheromone trap catches were reduced by up to 96–100% in the mating-disruption plots. During the first year of mating disruption a treatment with Bacillus thuringiensis (var. kurstaki ) (Bt) was applied to reduce the first generation or larvae. Fruit damage in the mating disruption plots was lower compared with the fruit damage in Bt, insecticide and untreated plots. In high fruiting years, the proportion of fruit damage was lower than in low fruiting years. Mating disruption applied in the same olive grove over several years progressively reduced the olive moth population from year to year.     

Mating disruption of Lobesia botrana (Lepidoptera: Tortricidae): effect of pheromone formulations and concentrations

The reluctance of Israeli vine growers to adopt the mating disruption technique to control the moth Lobesia botrana Den. & Schiff. has been attributed to the high cost of this method compared with that of traditional insecticide control. In this study, we tested the possibility of reducing the cost, first by testing different pheromone formulations (and thus open the market for competition) and second by reducing the pheromone concentration used in vineyards. Comparisons were made between two pheromone formulations--Shin-Etsu (Tokyo, Japan) at 165 g/ha and Concep (Sutera, Bend, OR) at 150 g/ha--and between two concentrations of Shin-Etsu, 165 and 110 g/ha. Pheromone dispensers were placed at the onset of the second moth generation. Comparison of the numbers of clusters infested with eggs and larvae of L. botrana showed no significant differences in the performance, either between the two formulations, or between the two tested concentrations. The results suggest that 1) the two formulations are equally effective, and 2) a low pheromone concentration is sufficient to maintain good control of small populations of L. botrana. However, when the population is high, pest control efficacy is not improved by increasing the pheromone concentration. Therefore, in the interest of reducing the relatively high cost of mating disruption, we emphasize that increasing the pheromone concentration does not provide improved control of high populations of L. botrana. The cost of mating disruption can be diminished by reducing the applied pheromone concentration and by using the least expensive pheromone formulations     

Pheromone pre-exposure and mating modulate codling moth (Lepidoptera: Tortricidae) response to host plant volatiles

Abstract 1 Two codling moth Cydia pomonella kairomonal attractants, ethyl (E,Z)‐2,4‐decadienoate (pear ester) and (E)‐β‐farnesene, were tested in an insecticide‐sprayed apple orchard and an orchard treated for mating disruption with synthetic pheromone (E,E)‐8,10‐dodecadienol (codlemone). Male captures with pear ester were higher in the pheromone‐treated than in the insecticide‐treated orchard, whereas captures with (E)‐β‐farnesene were not different. Subsequent wind tunnel experiments confirmed that pre‐exposure to sex pheromone codlemone increased the behavioural response of codling moth males to pear ester. This supports the idea that male attraction to the plant volatile pear ester and sex pheromone codlemone is mediated through the same sensory channels. 2 Pear ester is a bisexual codling moth attractant and even captures of female moths were significantly increased in the pheromone‐treated orchard. In the laboratory wind tunnel, pheromone pre‐exposure had no effect on female response to pear ester, but significantly more mated than unmated codling moth females flew upwind towards a pear ester source. Differences in mating status in insecticide‐treated vs. pheromone‐treated orchards may thus account for the differences in female trap captures with pear ester. 3 These findings are important with respect to monitoring of codling moth with pear ester in mating disruption orchards. They also emphasize the importance of host plant volatiles in pheromone‐mediated mating disruption, which has been neglected to date.     

Optimization of pheromone dosage for gypsy moth mating disruption

The effect of aerial applications of the pheromone disparlure at varying dosages on mating disruption in low‐density gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), populations was determined in field plots in Virginia, USA during 2000 and 2002. Six dosages [0.15, 0.75, 3, 15, 37.5, and 75 g active ingredient (AI)/ha] of disparlure were tested during the 2‐year study. A strongly positive dose–response relationship was observed between pheromone dosages and mating disruption, as measured by the reduction in male moth capture in pheromone‐baited traps and mating successes of females. Dosages of pheromone 15 g AI/ha (15, 37.5, and 75 g AI/ha) reduced the mating success of females by >99% and significantly reduced male moth catches in pheromone‐baited traps compared to untreated plots. Pheromone dosages <15 g AI/ha also reduced trap catch, but to a lesser extent than dosages 15 g AI/ha. Furthermore, the effectiveness of the lower dosage treatments (0.15, 0.75, and 3 g AI/ha) declined over time, so that by the end of the study, male moth catches in traps were significantly lower in plots treated with pheromone dosages 15 g AI/ha. The dosage of 75 g AI/ha was initially replaced by a dosage of 37.5 g AI/ha in the USDA Forest Service Slow‐the‐Spread (STS) of the Gypsy Moth management program, but the program is currently making the transition to a dosage of 15 g AI/ha. These changes in applied dosages have resulted in a reduction in the cost of gypsy moth mating disruption treatments.     

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.     

Control of pheromone biosynthesis in mated redbanded leafroller moths

Mating in the redbanded leafroller moth, Argyrotaenia velutinana, causes a permanent decline in pheromone titers. Three hours following the termination of mating, phermone titers were significantly decreased from premating levels, and titers remained low for at least four days after mating. Pheromone titers were similar in females that had been decapitated or mated for twenty-four hours. In the redbanded leafroller moth, two peptides control pheromone production. The pheromone biosynthesis activating neuropeptide is produced in the brain and the pheromonotropic bursa peptide is produced in the corpus bursae. Both peptides stimulated pheromone biosynthesis in mated females and extracts prepared from brains and bursae of mated females contained pheromonotropic activity. However, severing the ventral nerve cord before mating prevented the decline in pheromone titer that occurred in mated females. Hemolymph collected during scotophase from mated females did not have pheromonotropic activity, whereas hemolymph collected during scotophase from virgin females contained activity. These results indicate that mating produces a signal sent by the ventral nerve cord to the brain to stop the release of pheromone biosynthesis activating neuropeptide. © 1993 Wiley-Liss, Inc.     

Comparison of three dispenser distribution patterns for pheromone mating disruption of Paralobesia viteana (Lepidoptera: Tortricidae) in vineyards

Over two growing seasons, Isomate GBM-Plus tube-type dispensers releasing the major pheromone component of grape berry moth, Paralobesia viteana (Clemens) (Lepidoptera: Tortricidae), were evaluated in vineyards (Vitis spp.) in Michigan, New York, and Pennsylvania. Dispensers were deployed in three different density-arrangement treatments: 124 dispensers per ha, 494 dispensers per ha, and a combined treatment with 124 dispensers per ha in the vineyard interior and 988 dispensers per ha at the vineyard border, equivalent to an overall density of 494 dispensers per ha. Moth captures and cluster infestation levels were compared at the perimeter and interior of vineyards receiving these different pheromone treatments and in vineyards receiving no pheromone. Orientation of male moths to pheromone-baited traps positioned at the perimeter and interior of vineyards was reduced as a result of mating disruption treatments compared with the nontreated control. These findings were consistent over both years of the study. Disruption of male moth captures in traps varied from 93 to 100% in treated vineyards, with the 494 dispensers per ha application rates providing significantly higher level of disruption than the 124 dispensers per ha rate, but only in 2007. Measurements of percentage of cluster infestation indicated much higher infestation at perimeters than in the interior of the vineyards in all three regions, but in both sample positions there was no significant effect of dispenser density on cluster infestation levels in either year. The contrasting results of high disruption of moth orientation to traps in vineyards that also had low levels of crop protection from this pheromone treatment are discussed in the context of strategies to improve mating disruption of this tortricid pest.     

Integrated control of oriental fruit moth (Lepidoptera: Tortricidae) in peach orchards using insecticide and mating disruption

The efficacy of an integrated and a conventional oriental fruit moth, Grapholita molesta (Busck), control program was compared using 4-ha blocks of peach at three Niagara Peninsula farms during 1997-1999. In the integrated program, chlorpyrifos was used to control first-generation larvae and mating disruption using Isomate M100 pheromone dispensers was used to control the second and third generations. In the conventional program, chlorpyrifos was used to control first-generation larvae and pyrethroids were used to control larvae of the later generations. The average release rate of pheromone was 23.7-26.4 mg/ha/h over a period of 86-91 d. The pheromone treatment reduced the capture of moths in pheromone-baited traps on average by 98%, suggesting a high level of disruption. The integrated program provided control of oriental fruit moth similar to the control provided by a conventional program. The mean percentage of peach shoots infested with first- and second-generation larvae, and fruit infested with third-generation larvae was not significantly greater in the integrated-program blocks during the 3-yr study. The elimination of insecticide sprays from the integrated-program blocks did not result in an increase in damage caused by plant bugs. The incidence of damage caused by other pests was negligible in both the integrated and conventional blocks.     

Pheromone release rate determines whether sexual communication of Oriental fruit moth is disrupted competitively vs. non‐competitively

Communicational disruption mechanisms for Oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), were determined using a suite of mathematical tools and graphical operations that enable differentiation between competitive attraction and non‐competitive mechanisms of disruption. Research was conducted in 20 field cages, each covering 12 mature apple trees. Commercial monitoring lures releasing Oriental fruit moth pheromone at a rate of 0.04 μg h^?1 and distributed at densities of 0, 1, 2, 4, 8, and 17 per cage were used to evaluate the effect of low‐releasing dispensers on the disruption of sexual communication. Graphical analyses revealed that near‐female‐equivalent pheromone dispensers disrupted Oriental fruit moth competitively. Commercial mating disruption dispensers releasing Oriental fruit moth pheromone at 60 μg h^?1 and deployed at 0, 4, 6, 10, 15, 20, and 30 per cage were used to evaluate the effect of high‐releasing dispensers on the disruption of sexual communication. Oriental fruit moth disruption shifted to a non‐competitive mechanism for high‐releasing dispensers. This is the first time such a shift in disruption mechanism has been demonstrated against a background of otherwise identical experimental conditions. Near‐female‐equivalent pheromone dispensers were also used to quantify the additive effect of an attract‐and‐remove control strategy compared with competitive mating disruption. We report a five‐fold reduction in Oriental fruit moth captures under attract‐and‐remove compared to mating disruption using near‐female‐equivalent dispensers. Surprisingly, release of female Oriental fruit moths into these large‐cage disruption studies had no measurable impact on male trapping.     

Persistent effects of aerial applications of disparlure on gypsy moth: trap catch and mating success

In forest plots treated aerially with a plastic laminated flake formulation (Disrupt^® II) of the gypsy moth sex pheromone disparlure to disrupt gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), mating was monitored the year of treatment and 1–2 years after treatment to determine the effects of the treatment on suppression of trap catch and mating success. In the year of treatment, there was a greater than 95% reduction in trap catch and a greater than 98% reduction in mating success compared to controls. One year after treatment at a dosage of 37.5 g active ingredient (a.i.) ha^?1, trap catch was reduced by 46–56% and mating success was reduced by 60–79%. Both trap catch and mating success were significantly reduced compared to controls in plots treated 1 year previously at 15 g a.i. ha^?1. Trap catch, but not mating success, was significantly reduced 2 years after treatment at 37.5 g a.i. ha^?1. The efficacy of mating disruption (MD) treatments in the Slow‐the‐Spread of the Gypsy Moth program was significantly reduced 2 years compared to 1 year after treatment. No such reduction was observed in plots treated with aerial applications of Bacillus thuringiensis kurstaki. The higher apparent efficacy of MD treatments 1 year after application may result to some extent from the suppression of moth capture in pheromone traps from the persistent effects of the previous year's treatment.