Pheromone-mediated Mating Disruption Research Articles

Sensory Adaptation of Antennae and Sex Pheromone-Mediated Flight Behavior in Male Oriental Fruit Moths (Leptidoptera: Tortricidae) After Prolonged Exposure to Single and Tertiary Blends of Synthetic Sex Pheromone

Sensory adaptation has been measured in the antennae of male Grapholita molesta (Busck) after 15 min of exposure to its main pheromone compound (Z)-8-dodecen-1-yl acetate (Z8-12:OAc) at the aerial concentration of 1 ng/m(3) measured in orchards treated with pheromone for mating disruption. Exposing males to this aerial concentration of Z8-12:OAc for 15 min, however, had only a small effect on their ability to orientate by flight to virgin calling females in a flight tunnel. Experiments were undertaken to determine if exposure to the main pheromone compound in combination with the two biologically active minor compounds of this species, (E)-8-dodecen-1-yl acetate (E8-12:OAc) and (Z)-8-dodecen-1-ol (Z8-12:OH) would induce greater levels of sensory adaptation and have a greater effect on male sexual behavior. The exposure of male antennae to 0.5 g/m(3) air of one of the three pheromone compounds induced sensory adaptation to this compound and to the other two pheromone compounds demonstrating cross adaptation. Average percentage sensory adaptation to a pheromone compound was similar after 15 min of exposure to 1 ng/m(3) air of Z8-12:OAc, or to 1 ng/m(3) air of a 1:1:1 or 93:6:1 blend of Z8-12:OAc, E8-12:OAc, and Z8-12:OH. The exposure of males to 1 ng/m(3) air of Z8-12:OAc or the two ratios of Z8-12:OAc, E8-12:OAc, and Z8-12:OH for 15 min had no effect on their ability to orientate to a virgin calling female. The implications of these results for the operative mechanisms of sex pheromone-mediated mating disruption of this species are discussed.

Chemical Ecology and Management of Lobesia botrana (Lepidoptera: Tortricidae)

The moth Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae) feeds on grapes (Vitis vinifera L.), reducing yield and increasing susceptibility to fungal infections. L. botrana is among the most economically important insects in Europe and has recently been found in vineyards in Chile, Argentina, and California. Here, we review L. botrana biology and behavior in relation to its larval host (the grapevine) and its natural enemies. We also discuss current and future control strategies in light of our knowledge of chemical ecology, with an emphasis on the use of the sex pheromone-based strategies as an environmentally safe management approach. Pheromone-mediated mating disruption is the most promising technique available on grapes and is currently implemented on approximately 140,000 ha in Europe. Experience from several growing areas confirms the importance of collaboration between research, extension, growers, and pheromone-supply companies for the successful implementation of the mating disruption technique. In the vineyards where mating disruption has been successfully applied as an areawide strategy, the reduction in insecticide use has improved the quality of life for growers, consumers, as well as the public living near wine-growing areas and has thereby reduced the conflict between agricultural and urban communities.

Mating disruption of the ambrosia beetle Megaplatypus mutatus in poplar and hazelnut plantations using reservoir systems for pheromones

Megaplatypus mutatus (Chapuis) (Coleoptera: Curculionidae: Platypodinae) is an ambrosia beetle native to South America, but it has recently been introduced into Italy and represents a serious problem in commercial poplar and fruit tree plantations. Male M. mutatus emit a sex pheromone composed of (+)-6-methyl-5-hepten-2-ol [(+)-sulcatol], 6-methyl-5-hepten-2-one (sulcatone), and 3-pentanol. We performed three field trials of mating disruption of M. mutatus in hazelnut and poplar plantations in Argentina and Italy. To perform these tests, we made plastic pheromone reservoir-type dispensers for sulcatol, sulcatone, and 3-pentanol with zero-order kinetics that were deployed in the field during the female flight period. The number of galleries where mating took place was significantly higher in control than in treated areas, indicating that pheromone application had interfered with female behavior and male localization. Because damage reduction was >56% in both countries, these results demonstrate the potential for the strategy of pheromone-mediated mating disruption of M. mutatus in commercial poplar and hazelnut plantations. Also, our study provides the first evidence for successful pheromone-mediated mating disruption in a forest beetle.

Quantifying the Benefits of Areawide Pheromone Mating Disruption Programs that Target Codling Moth (Lepidoptera: Tortricidae)

A 4 yr research and implementation project in Michigan apple production showed that deploying pheromone-mediated mating disruption for codling moth, Cydia pomonella L., in an areawide (AW-CMMD) program where mating disruption is established on all apple-producing acreage on individual and adjacent farms significantly improves control of codling moth. The areawide project was compared with mating disruption applied to individual apple blocks (Block-CMMD) on farms with other orchard acreage not under disruption, or apple blocks not treated with mating disruption (No-CMMD). Pheromone-baited traps were deployed at 1/ha over 850 ha of AW-CMMD and 16 ha of Block-CMMD; 16 ha were not treated. Average captures of codling moth in AW-CMMD declined each season and were lower than in the Block-CMMD and the No-CMMD programs. Captures of male codling moth in pheromone-baited traps were reduced 93% by year 4 of the project in AW-CMMD orchards. Injury to fruit and the overall number of insecticides targeting codling moth decreased each year in the areawide program; in Block-CMMD orchards, injury levels remained about the same with slight reductions in insecticide use from year, and in the No-CMMD orchards, injury increased significantly, but insecticide use varied little from year to year. Growers who implemented AW-CMMD realized a mean savings of $55–65/ha through reduced fruit injury and use of insecticides as compared with orchards using insecticide-only programs. This Michigan project demonstrates that an areawide approach to mating disruption improves the benefits of deploying pheromone in individual blocks.

Efficacy of Mating Disruption for Control of the Coffee Leaf Miner

The coffee leaf miner, Leucoptera coffeella (Guerin-Meneville) (Lepidoptera: Lyonetiidae), is the main pest of coffee plantations in Brazil. Indiscriminate chemical control has been used frequently to control the attack of L. coffeella, causing serious problems to the environment. To avoid such problems, new techniques have been developed to control the attack of this pest. A technique to control lepidopteran pests, called mating disruption, aims to obstruct the communication among sexual partners. The potential of pheromone-mediated mating disruption for control of leaf miner population was evaluated in a coffee plantation in Patrocinio-MG, Brazil. Three experimental areas were installed: 20 ha plot treated with synthetic sex pheromone; another 20 ha plot with insecticide applications and 20 ha plot maintained as control. The pheromone plot was treated with 400 pheromone dispensers with 1g of 5,9-dimethylpentadecane per dispenser. The efficacy of mating disruption was evaluated by the comparison of number of males caught in delta traps (20 traps per plot) baited with 0.5 mg of 5,9 - dimethylpentadecane. The number of mined leaves was also recorded in each plot. The presence of pheromone did not reduce the number of males caught nor decreased the number of mined leaves in the plot. The failure of the mating disruption technique may be attributed to a combination of several factors, such as composition and dose of the pheromone and its formulation, the moment of application in the crop, the population density at the begin of the experiment and climatic factors.

Codling Moth Management and Chemical Ecology

Lepidopteran insects use sex pheromones to communicate for mating. Olfactory communication and mate-finding can be prevented by permeating the atmosphere with synthetic pheromone. Pheromone-mediated mating disruption has become a commercially viable pest management technique and is used to control the codling moth, Cydia pomonella, a key insect pest of apple, on 160,000 ha worldwide. The codling moth sex pheromone, codlemone, is species specific and nontoxic. Orchard treatments with up to 100 grams of synthetic codlemone per hectare effectively control codling moth populations over the entire growing season. Practical implementation of the mating disruption technique has been realized at an opportune time, as codling moth has become resistant to many insecticides. We review codling moth chemical ecology and factors underlying the behavioral mechanisms and practical implementation of mating disruption. Area-wide programs are the result of collaborative efforts between academic research institutions, extension, chemical industries, and grower organizations, and they demonstrate the environmental and economic relevance of pheromone research.

Disruption of Pheromone Communication in <I>Tecia solanivora</I> (Lepidoptera: Gelechiidae): Flight Tunnel and Field Studies

The moth Tecia (Scrobipalpopsis) solanivora Povolny (Lepidoptera: Gelechiidae) is the most important pest of potato, Solanum spp., in Central America and adjacent South American countries. Insecticide treatments are not sufficiently effective; therefore, we investigated the feasibility of pheromone-mediated mating disruption for control of T. solanivora. Pheromone dispensers were formulated with 70 mg of the three sex pheromone compounds (E)-3-dodecenyl acetate, (Z)-3-dodecenyl acetate, and dodecyl acetate, in a ratio of 100:56:100, respectively. Male attraction to these compounds is optimal at a ratio of 100:1:20, thus the mating disruption dispensers contained an off-blend, which attracted only a few males. Nonetheless, one mating disruption dispenser suppressed male attraction to calling females in a flight tunnel and reduced male activation in response to female pheromone. Communication disruption is accordingly due to camouflage of the female signal and possibly due to a reduction of male responsiveness by sensory imbalance. Only a few males were observed in a 3-ha potato field treated with 84 g pheromone/ha, compared with an untreated control field. During 2 mo, male attraction to traps baited with calling females or synthetic pheromone was strongly reduced. This reduction confirms the potential of mating disruption for management of T. solanivora. The efficacy of the pheromone treatment can be further improved by earlier dispenser application, by increased dispenser load, and by treatment of larger fields to reduce immigration of mated females.

Impact of sub-lethal residues of azinphos-methyl on the pheromone-communication systems of insecticide-susceptible and insecticide-resistant obliquebanded leafrollers Choristoneura rosaceana (Lepidoptera: Tortricidae).

The effects of sub-lethal residues of azinphos-methyl on pheromone production, calling, female attractiveness and the ability of males to locate sources of natural and synthetic pheromone were compared in azinphos-methyl-susceptible (susceptible) and azinphos-methyl-resistant (resistant) obliquebanded leafrollers, Choristoneura rosaceana (Harris). The amount of pheromone in susceptible females was reduced by 29-33% after exposure to azinphos-methyl; this treatment did not affect the pheromone content of resistant females. Azinphos-methyl-treated resistant females contained 39-43% less pheromone than azinphos-methyl-treated susceptible females. Resistant females that were not treated with azinphos-methyl contained 35-56% less pheromone than susceptible females that were not treated with insecticide. The incidence of calling was reduced by 67-100% in azinphos-methyl-treated susceptible females; the incidence of calling by resistant females was not affected by exposure to azinphos-methyl. The incidence of calling by azinphos-methyl-treated susceptible females was 58-100% lower than that of azinphos-methyl-treated resistant females. There was no difference in the incidence of calling between susceptible and resistant females that had not been treated with insecticide. In a flight tunnel, treatment with insecticide reduced the attractiveness of susceptible females by 38%; treatment with insecticide did not affect the attractiveness of resistant females. There was no difference in the proportion of males attracted to susceptible and resistant females that had, or had not been treated with insecticide. In an apple orchard, the attractiveness of susceptible and resistant females treated with azinphos-methyl was reduced by 84 and 12%, respectively. The proportion of males attracted to azinphos-methyl-treated susceptible females was 58% lower than the proportion attracted to azinphos-methyl-treated resistant females, whereas, if females were not treated with insecticide, the proportion attracted to resistant females was 57% lower than the proportion attracted to susceptible females. In a flight tunnel, azinphos-methyl did not affect the ability of susceptible or resistant males to locate a source of pheromone gland extract. Likewise, in an apple orchard, the insecticide treatment had no effect on the ability of susceptible or resistant males to locate a source of synthetic pheromone. In a flight tunnel, there was no difference in the proportion of azinphos-methyl-treated susceptible and resistant males locating a source of pheromone gland extract; however, in the orchard, 39% fewer azinphos-methyl-treated resistant males located a source of synthetic pheromone than azinphos-methyl-treated susceptible males. A similar proportion of susceptible and resistant males that had not been treated with insecticide located a source of pheromone gland extract in the flight tunnel, but in the orchard, the proportion of resistant males not treated with azinphos-methyl that located the source of synthetic pheromone was 32% lower than the proportion of susceptible males not treated with this insecticide. The implications of the differences in the effect of sub-lethal residues of azinphos-methyl on the pheromone communication system of susceptible and resistant moths are discussed in relation to the theory of the development of insecticide resistance, the detection of resistance in feral populations of moths using sex pheromone-baited traps, and the control of moths using sex pheromone-mediated mating disruption.

TOWARD PHEROMONE-BASED MATING DISRUPTION OF ENARMONIA FORMOSANA (LEPIDOPTERA: TORTRICIDAE) ON ORNAMENTAL CHERRY TREES

AbstractThe potential for pheromone-mediated mating disruption of the cherry bark tortrix (CBT), Enarmonia formosana (Scopoli), was evaluated by attaching PVC tube dispensers to the trunks of mature (> 40 cm diameter at breast height) ornamental cherry trees, Prunus cvs., lining suburban streets of New Westminster and Vancouver, British Columbia. Dispensers released either a blend of (E)-9-dodecenyl acetate (E9-12:OAc, 49.5%), (Z)-9-dodecenyl acetate (Z9-12:OAc, 49.5%), and (Z)-7-decenyl acetate (Z7-10:OAc, 1%) at a rate of 29 mg/day (Exp. 1), or E9-12:OAc alone at 27 mg/day (Exp. 2), 4 mg/day (Exp. 3), or 0.5 mg/day (Exp. 4). A sticky Delta trap baited with a grey rubber septum impregnated with CBT pheromone components E9-12:OAc (40 μg), Z9-12:AOc (60 μg), and Z7-10:OAc (1 μg) was placed in each tree. Captures of male CBTs in treatment trees were significantly reduced compared with control trees in all experiments. Results suggest that disruption of pheromone-based communication in CBT around individual cherry trees is feasible with a pheromone blend or with E9-12:OAc alone, and could become part of an integrated management strategy for CBT in urban environments.

Control of the codling moth (cydia pomonella) in apple and pear orchards in Israel by mating disruption

Control of the codling moth,Cydia pomonella (L.) (Lepidoptera: Tortricidae), by pheromone-mediated mating disruption, was studied in Israel using two types of dispensers: Shin-Etsu twist-tie (normal and long-life) and TNO matrix formulation (square wafers). Factors affecting mating disruption: initial pest population density, timing of the pheromone application, early season insecticide treatments and monitoring of the pest, were evaluated. Efficacy of mating disruption was assessed by comparing catch of males in pheromone traps located in pheromone-treated and chemically sprayed control plots. Fruit infestation during the season and at picking time was the major criterion to assess mating disruption. The preferred time for pheromone application was before the first flight of the moth. When pheromones were applied at a later stage, one or two early insecticide sprays had to be used to reduce the initial level of the codling moth population. In all tests, trap catch in pheromone-treated plots was drastically reduced as compared with respective control plots. In pheromone-treated plots where total seasonal trap catch (after pheromone application) was less than 12 males/trap, fruit infestation was less than 1.5%; zero trap catch resulted in 0.1-0.3% infestation. At high population levels, mating disruption was ineffective, with the rate of infestation at picking-time being similar in pheromone-treated and control plots. All the field tests indicated that mating disruption with either Shin-Etsu ropes or TNO squares can control codling moth infestations in apple and pear orchards, at relatively low densities of the pest, as efficiently as commercial insecticide sprays.

MATING DISRUPTION FOR CONTROLLING THE CODLING MOTH, CYDIA POMONELLA (L.) (LEPIDOPTERA: TORTRICIDAE), IN ORGANIC APPLE PRODUCTION IN SOUTHWESTERN ONTARIO

AbstractSex pheromone-mediated mating disruption using Isomate-C® pheromone dispensers was evaluated as a means of controlling the codling moth, Cydia pomonella, over three consecutive growing seasons in organically managed blocks of apples at two commercial apple orchards in Ontario. The objective of the study was to determine if mating disruption could be used to stabilize or reduce the amount of damage caused by indigenous codling moth populations. The emission rate of the pheromone dispensers was estimated using volumetric and gravimetric methods. Efficacy of the pheromone treatment was assessed by comparing pheromone-baited trap catches of adult male codling moths in pheromone- and insecticide-treated blocks of apples, and by estimating damage caused by first- and second-generation codling moths in pheromone- and insecticide-treated blocks as well as in small plots of apples where the codling moth was not controlled. The estimated average release rate of pheromone varied from 22.2 to 30.3 mg per ha per h. The seasonal total number of adult male moths trapped in the pheromone-treated blocks was from 3.8 to 25.3% of the number trapped in insecticide-treated blocks; during one season at one farm, no moths were trapped in a pheromone-treated block. Treatment with pheromone did not prevent an increase in codling moth damage. At one farm, damage increased ca. 5-fold during the 3-year study. At the other farm, damage increased ca. 4-fold during two consecutive growing seasons in one block and ca. 4-fold during three consecutive seasons in the other block. At both farms there was a marked increase in the amount of damage between the first and second generations of the pest. Possible reasons for the failure of the pheromone treatment to prevent increases in codling moth damage are discussed.

Initial Studies of Mating Disruption of the Black headed Fire worm of Cranberries (Lepidoptera: Tortricidae)

We assessed the potential of pheromone-mediated mating disruption to control the black headed fire worm of cranberries, Rhopobota naevana (Hubner). In experimental plots (30 by 30 m) on cranberry farms, spiral polyvinyl chloride pheromone dispensers released either the main component of fire worm pheromone, (Z)-ll-tetradecen-l-ol acetate, or a 3-component blend, (Z)-ll-tetradecen-l-ol acetate, (Z)-ll-tetradecen-l-ol, and (Z)-9-dodccen-1-ol acetate, which is similar to the natural pheromone. In both years of the study, the incidence of mating of laboratory-reared female moths placed in pheromone-treated plots was reduced relative to those placed in control plots. Release rates of pheromone, which were estimated from the curvilinear relationship between the amount remaining in dispensers and time in the field, declined linearly and slowly over the experimental period. The estimated release ratio of the 3-component blend decreased from 5.2:1.9:1.0 at the beginning of the Season to 1.9:1.1:1.0 at the end. Results suggest that mating disruption is a promising technique for Immagement of the black headed fire worm.

CONTROL OF ORIENTAL FRUIT MOTH BY MATING DISRUPTION USING SEX PHEROMONE IN THE NIAGARA PENINSULA, ONTARIO

AbstractDisruption of mating for control of Oriental fruit moth [Grapholita molesta (Busck) (Lepidoptera: Tortricidae)] using Isomate M pheromone dispensers was tested from 1987 to 1990 in the Niagara Peninsula of Ontario. The effectiveness of pheromone was evaluated using virgin female-baited traps, synthetic pheromone-baited traps, and by inspecting samples of twigs and fruit for evidence of G. molesta damage. No males were caught in virgin female-baited traps placed in pheromone-treated plots. Synthetic pheromone-baited trap catches of male moths were reduced by 85–100%. Pheromone provided commercially acceptable control over two consecutive growing seasons at a commercial farm with a relatively low density G. molesta population. Pheromone did not provide commercially acceptable control at an experimental farm with a relatively high density G. molesta population. The incidence of capture of males in virgin female-baited traps, in synthetic pheromone-baited traps, and the incidence of damage to peach twigs by first- and second-generation G. molesta larvae could not be used to predict the incidence of damage to fruit at harvest. The results suggest that pheromone-mediated mating disruption may have potential as a method for controlling the Oriental fruit moth in orchards with relatively low density populations.

Parasitism of Tufted Apple Bud Moth (Lepidoptera: Tortricidae) in Conventional Insecticide and Pheromone-Treated Pennsylvania Apple Orchards

A faunistic study was conducted over a four year period in apple orchards utilizing different pesticide management strategies to determine the parasitoid complex of the tufted apple bud moth, Platynota idaeusalis (Walker). The relative effectiveness of these parasitoids as control agents in conventional orchards using broad-spectrum insecticides was compared to those using pheromone-mediated mating disruption to control P. idaeusalis. Limited samples were also taken of other tortricids found in these orchards to determine if they were serving as alternate hosts for P. idaeusalis parasitoids. Thirty-one parasitoid and two hyperparasitoid species were recovered during this study which, when combined with other records, present a total parasitoid complex of 41 species for P. idaeusalis. Total parasitism was higher for summer brood P. idaeusalis larvae in mating disruption orchards than in conventional orchards. Total parasitism of the overwintering brood of P. idaeusalis was higher than the summer brood in conventional orchards. Rates of parasitism were comparable in mating disruption blocks during both broods. The ichneumon Exochus atriceps Walsh. was the most common parasitoid species, and it attacked both broods of P. idaeusalis. The braconids Meteorus trachynotus Viereck, Bassus anulipes (Cresson), B. cinctus (Cresson), Apanteles polychrosidis Viereck, and an Apanteles sp. near edwardsii Riley were also common but they attacked only the overwintering brood. Four undescribed species of braconids were found during this study.

A MODIFIED LIVE-TRAP FOR ASSESSING MATING DISRUPTION OF MICROLEPIDOPTERA

In field studies of pheromone-mediated mating disruption of lepidopteran pests, there are several ways to determine if mate location has been disrupted. One indirect method is to count the number of males caught in sticky traps baited with synthetic pheromone. A reduced catch in pheromone-treated plots relative to control plots shows that males were unable to find the source of synthetic pheromone and suggests that mating has been disrupted. More direct methods are: (1) to count the number of males attracted to sticky traps baited with virgin females; or (2) to assess the incidence of mating of (a) feral females collected in light-, bait- or other traps, (b) females caged with males in pheromone-treated areas, or (c) virgin females placed in the field and later retrieved. Females may be tethered with thread to non-sticky traps or partially dealated and placed on a “mating table” from which they cannot escape.

EFFICACY OF MATING DISRUPTION FOR CONTROLLING THE GRAPE BERRY MOTH, ENDOPIZA VITEANA (CLEMENS) (LEPIDOPTERA: TORTRICIDAE), A CASE STUDY OVER THREE CONSECUTIVE GROWING SEASONS

AbstractSex pheromone-mediated mating disruption was used to control the grape berry moth, Endopiza viteana (Clemens) (Lepidoptera: Tortricidae), at two farms in the Niagara peninsula, Ontario, during three consecutive growing seasons, 1989 through 1991, to determine if earlier observed between-generation increases in the percentage of infested grape clusters would continue between growing seasons. The relative performance of the pheromone treatment was assessed by comparing the percentage of infested clusters in the pheromone-treated plot with the percentage of infested clusters in an adjacent, insecticide-treated plot. Although the percentage of infested clusters increased from 1.7- to 56.5-fold between successive generations in the pheromone-treated plots, there was no indication that the level of infestation at harvest affected the level of infestation the following spring. At one farm, the percentage of infested clusters was greater in the pheromone-treated than in the insecticide-treated plot during 1989, but during 1990 and 1991, the level of infestation was similar in the two plots. At the other farm, the level of infestation was from 2- to 3-fold greater in the insecticide-treated than in the pheromone-treated plot.

Control of Codling Moth in Apple and Pear with Sex Pheromone-Mediated Mating Disruption

During 1987-1988 replicated 0.3-ha plots of apple and pear were used to measure the efficacy of sex pheromone-mediated mating disruption of codling moth, Cydia pomonella (L.). Comparisons of fruit injury were made between pheromone-treated and untreated plots either with or without releases of field-collected moths. In IH87, one moth per tree was released twice during the season in two apple orchards and total season fruit injury in untreated plots ranged from 7.0 to 21.2%. Levels of fruit injury in the pheromonetreated plots were 1.0-4.0%. In 1988, either one moth was released per five trees three times during the season or no moths were released in replicated apple plots. Seasonal fruit injury ranges in untreated plots were 1.41-1,65% and 0.39-1.21% with and without moth releases, respectively. Correspondingly, levels of fruit injury in the pheromonetreated plots were 0.09-0.27% and 0.05-0.07% with and without moth releases, respectively. In 1988, fruit injury in the pheromone-treated and untreated pear plots with moth releases were 0.05 and 0.16%, respectively. Average emission levels of (E, E)-8,10- dodecadien-l-ol at dusk for a 14-d period after releases were 8.4-40.9 mg/ha per h each year. Spatial analysis of fruit injury showed that fruit injury was aggregated and moth movement within orchards was limited and not influenced by the presence of pheromone. Our data suggested that more fruit injury occurred on ‘Golden Delicious’ than ‘Red Delicious’.