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

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

不同剂型迷向剂处理对苹果蠹蛾控制效果比较

【背景】苹果蠹蛾是我国重要的检疫性害虫,目前从新疆迅速向东部扩散。苹果蠹蛾性信息素胶条迷向剂对防控苹果蠹蛾高效、安全,但成本较高。【方法】2013年在宁夏中卫市常乐镇马路滩村果园使用3种不同剂型的迷向剂对苹果蠹蛾进行了防治试验,每个处理果园面积3.3 hm~2,分别使用性诱剂处理后,用诱捕器监测处理后的诱蛾量,在生长期调查果实为害率,比较防治效果。【结果】通过整个生长季诱捕器监测,悬挂点以900个·hm~(-2)双层处理,胶条迷向剂在开花前处理1次,整个生长季处理区中心部位没有监测到苹果蠹蛾成虫;透明塑管迷向剂分别在开花前和6月底处理2次,整个生长季中心部位平均每个诱捕器诱到3.3头雄蛾;膏体迷向剂分别在开花前和6月底处理2次,整个生长季中心部位平均每个诱捕器诱到12头雄蛾。在6月下旬和果实采收前进行果实为害率调查,胶条迷向剂区平均蛀果率分别为0和0.56%,透明塑管迷向剂区蛀果率分别为0.89%和1.38%,膏体迷向剂处理区蛀果率分别为0.79%和1.38%。常规农药防治区2个时期蛀果率分别为1.44%和3.13%。【结论与意义】综合考虑防治效果和使用成本,在虫口密度高、效益高的果园可以使用胶条迷向剂,膏体迷向剂和透明塑管迷向剂只有在虫口密度较低的情况下使用。     

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.     

应用性信息素迷向法防治茶毛虫的田间试验

2003年在贵州省黔南州都匀茶场进行了性信息素迷向法防治茶毛虫Euproctis pseudoconspersaStrand的田间试验。通过比较处理区和对照区内茶毛虫发蛾量、交配率和后代虫口密度,发现剂量为0.5mg的性信息素释放器按5 m的间隔施放的防治效果显著好于其它处理,它在越冬代和第1代试验中茶毛虫诱蛾量分别减少83.90%和70.25%,交配率分别下降78.18%和73.21%,虫口密度减少59.02%和45.71%。试验结果表明性信息素迷向法可以作为防治茶毛虫的一种手段。     

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.     

Management of diamondback moth,Plutella xylostella (Lepidoptera: Plutellidae) by mating disruption

Abstract Field trials were conducted in China in 2008 and 2009 to evaluate the efficacy of mating disruption (MD) on diamondback moth, Plutella xylostella, in cabbage, Brassica oleracea var. capitata. Effectiveness was positively correlated with the MD dispenser density in the field. A density of 167 MD dispensers per ha produced an average population decrease of about 50% compared to the conventional‐practice field. Significant fewer males were captured in pheromone‐treated and conventional‐practice fields than in the blank control field, but the difference was not significant between the pheromone‐treated and conventional‐practice fields. In addition, fewer eggs and larvae were observed in pheromone‐treated fields. Our results suggest mating disruption coupled with minimal insecticidal supplements is a promising solution for resistance management and control of diamondback moth infestation.     

Mating disruption barriers in pome fruit for improved control of oriental fruit moth Grapholita molesta Busck (Lep., Tortricidae) in stone fruit under mating disruption

Oriental fruit moth (OFM) Grapholita molesta Busck (Lep., Tortricidae) is a very important pest in commercial orchards in Victoria, Australia. Pheromone‐mediated mating disruption (MD) applied in stone fruit orchards successfully controlled OFM populations for many years, but damage to shoot tips and fruit at the edge of peach blocks located adjacent to pear blocks under insecticide treatments has become problematic. To improve protection of stone fruit against edge damage and outbreaks of OFM, all orchards were treated with sex pheromone dispensers for MD on an area‐wide basis. Area‐wide MD treatment, including all pome and stone fruit orchards in a discrete area, successfully controlled edge infestations of OFM, but was expensive. To reduce the cost of OFM control, sex pheromone dispensers for MD were applied as barrier treatments to 54–60 m of neighbouring pears adjacent to peaches under MD. Detailed monitoring of the OFM population, shoot tip and fruit damage assessments indicated that application of MD barriers on pears during two consecutive seasons provided sufficient control of OFM on peaches. This MD barrier treatment was able to reduce the number of OFM caught in all experimental peach blocks, with damage to shoot tips and fruit giving similar results to MD treatment of the whole neighbouring pear block. Extending the MD treatment area for 54–60 m into the neighbouring pear block significantly reduced the edge damage in MD‐treated peaches in the first season and almost eliminated OFM damage in the second season.     

An isometric virus of the potato tuber moth Tecia solanivora (Povolny) (Lepidoptera: Gelechiidae) has a tri-segmented RNA genome

A small isometric virus has been isolated from larvae of the Guatemala potato tuber moth, Tecia solanivora (Povolny), collected in Ecuador. It was designated the Anchilibi virus (AnchV). The non-enveloped viral particles have an estimated diameter of 32 ± 2 nm. Three major proteins were found in virions, with estimated sizes of 102.0 ± 2.1, 95.8 ± 2.0 and 92.4 ± 1.5 kDa for AnchV as determined by polyacrylamide gel electrophoresis. After denaturing agarose gel electrophoresis, the genome of AnchV appeared to be a tri-segmented single-stranded RNA with fragment sizes of 4.1 ± 0.2, 2.8 ± 0.2 and 1.65 ± 0.2 kb. In addition to a high virulence towards its original host, AnchV also caused high mortality in larvae of two other potato tuber moth species, Phthorimaea operculella (Zeller) and Symmetrischema (tangolias) plaesiosema (Turner). Electron microscopy confirmed that AnchV replication occurs in the cell cytoplasm, mainly in vesicles. Several important characteristics exhibited by this virus differ from those reported for known families of insect viruses. Thus, AnchV might be member of a new taxonomic group.     

梨小食心虫化学通信中的信息物质

梨小食心虫Grapholitha molesta Busck是我国北方果区发生的重要害虫。当前对该虫的防治主要依赖化学农药, 但引起的害虫抗药性、 杀伤天敌和环境污染等问题非常严重。食心虫自身的信息素、 寄主/非寄主的他感化学物质对于调节其配偶选择和寄主定位起着至关重要的作用, 基于信息化学物质的害虫管理策略为果园食心虫的治理提供了新的途径。本文综述了国内外有关梨小食心虫化学信息物质研究进展, 包括雌蛾释放的性信息素组分及对雄、 雌两性的引诱, 雄蛾释放的信息素, 利用性信息素的迷向研究, 寄主植物挥发性引诱物质的鉴定和筛选, 以及梨小食心虫寄主转换机制等方面的研究现状和存在的问题。具体来说, 雌蛾的性信息素包括顺-8-十二碳烯醋酸酯、反-8-十二碳烯醋酸酯、顺-8-十二碳烯-1-醇和十二碳-1-醇, 各个组分的比例在地理种群间存在变异。在室内, 通过行为试验证实两种醋酸酯对雄蛾的引诱是必不可少的, 微量的顺-8-十二碳烯-1-醇对二元组分起到增效作用。在田间, 上述3种物质组成的诱芯具有较强的活性; 由此开发的性信息素迷向技术（人工迷向丝、 可喷施的微胶囊和蜡滴）被用于梨小食心虫交配干扰, 取得了很好的效果。梨小食心虫最主要的寄主植物桃梢挥发物包括22种化合物, 其中绿叶挥发物占到50%, 行为生测证实6~8个碳原子的物质是主要的活性化合物。顺-3-己烯丁酸酯、顺-3-己烯醇、反-2-己烯醛、苯甲醛和苯甲腈的五组分混合物, 其引诱力与天然桃梢挥发物相当。通过钙成像试验证实, 尽管苯甲腈在桃梢天然挥发物中仅占0.14%, 但雌蛾对含有该物质的混合物有显著趋性, 该物质对梨小食心虫成功识别寄主具有重要意义。最后对梨小食心虫信息化学物质下一步的研究和应用前景进行了探讨。     

Isolation and characterization of polymorphic microsatellites in the Potato Tuber Moth Tecia solanivora (Povolny, 1973) (Lepidoptera: Gelechiidae)

Nine polymorphic microsatellite markers were isolated from Tecia solanivora, one of the most serious pests of potato tubers in Central and South America. As found in other studies of Lepidoptera, development of microsatellites is a difficult task: in our case, despite the large number of clones sequenced (796), of which 70 were unique, only nine loci were found to be both variable, and in Hardy-Weinberg equilibrium, No null alleles were detected. The loci were tested in three other co-occurring Gelechiidae species, one of which was variable. These loci will be used to provide a greater understanding of the genetic changes occurring during the invasive process in this species.     

苹果蠹蛾性信息素缓释剂的控害效果

2010年在甘肃、宁夏、黑龙江3地对苹果蠹蛾Cydia pomonella(L.)性信息素缓释剂(购自澳大利亚Bioglobal公司;性信息素含量为0.16g/根)对苹果蠹蛾的迷向防治效果进行了试验;观察了不同生态区设置不同缓释剂密度的防治效果和持效期。结果表明,在低虫口密度下,在不同生态区每公顷悬挂660、990和1320根性信息素迷向丝,均能取得较好的防治效果;在越冬代活动前处理,基本上可以控制整个生长期苹果蠹蛾对果实的为害。在新侵入的低密度果园,通过诱蛾监测、调查蛀果和树干绑诱虫带等验证方法,初步证明使用该性信息素缓释剂处理1年可以达到铲除的效果。依据本研究结果,结合防治成本,在苹果蠹蛾发生地区,采用660根/hm2的悬挂密度使用进口性信息素缓释剂处理果园可以达到良好的防治效果。     

Characterization of a Costa Rican granulovirus strain highly pathogenic against its indigenous hosts,Phthorimaea operculella and Tecia solanivora

A granulovirus isolate collected from diseased Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae) larvae in Costa Rican potato [Solanum tuberosum L. (Solanaceae)] crops was characterized at the molecular and biological level. Restriction endonuclease analysis identified this isolate as a novel P. operculella granulovirus (PhopGV) (Baculoviridae: Betabaculovirus) strain and was designated as PhopGV‐CR1. In addition, PCR amplification of four specific variable genomic regions yielded multiple amplicons for two open reading frames, revealing the presence of different genotypic variants within the virus population. Biologically, PhopGV‐CR1 was highly pathogenic for its two indigenous hosts, although significant differences of up to four‐fold were detected against P. operculella [LD₅₀ = 17.9 occlusion bodies (OBs) mm^?2] and Tecia solanivora (Povolny) (Lepidoptera: Gelechiidae) (LD₅₀ = 69.1 OBs mm^?2). The two P. operculella colonies, from Costa Rica and France, were equally susceptible to PhopGV‐CR1. Serial passage of PhopGV‐CR1 over four generations in T. solanivora increased its pathogenicity by five‐fold in three generations, suggesting an ongoing adaptation to its alternate host.     

Dispersal of potato tuber moth estimated using field application of Bt for mark-capture techniques

A new mark-capture technique involving field applications of Bacillus thuringiensis Berliner (Bt) to study the dispersal of potato tuber moth, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae), was investigated as a tool to improve information on the potential impact of insect pest dispersal on crop infestation and insecticide resistance. The acquisition and persistence of Bt on moths were characterized and potential contamination of moths from naturally occurring Bts was examined. This mark-capture technique was developed to mark larger numbers of moths than had been previously achieved with laboratory marking using fluorescent dyes in mark-release-recapture experiments. Applications of commercial preparations of Bt to 0.3 and 1.0 ha potato fields were estimated to have marked ca. 50 000 moths in each experiment. Pheromone trap catches of potato tuber moths in the Bt-sprayed fields and in potato fields at distances of ca. 80, 200, 350, and 750 m were assayed for the Bt marker using selective microbiological media and identification of characteristic Bt crystal inclusions. Marking rates of moths were 78–100% in the sprayed fields and, compared with our previous mark-release-recapture studies, marking at ca. 200 m was increased by 15–18-fold to >3.0 moths per trap. This capture rate allowed the calculation of a dispersal curve that improved the reliability of estimates of movement at farm-scale distances. These estimates indicated that 10% of the population dispersed to 240 m in 3 days, and suggested that moths can potentially disperse throughout a typical potato-growing area in one growing season. This level of dispersal has implications for the spread and management of potato tuber moth populations, especially if insecticide resistance is present.     

Interference with the mate-finding communication system of the Chinese tortrix Cydia trasias (Lep., Olethreutidae) using synthetic sex pheromones

Abstract: Interference with the mate-finding communication system of Cydia trasias (Meyrick) using sex pheromone dispensers (60% E8,E10-dodecadienyl acetate and 40% E8,E10-dodecadien-1-ol, 0.5 mg/dispenser) was investigated in three plots of the Chinese scholar-tree, Sophora japonica L., in Beijing, China, in 2000. Treatments were evaluated by pheromone-baited traps, caged virgin females, pupating and hibernating populations on tree trunks, and assessment of larval damage in petioles and seed pods. Six to eight natural rubber septum dispensers were placed in each tree at the pheromone-treated plots at three separate periods: at the beginning of overwintering generation flight, the first- and the second-generation flights. Application of pheromone dispensers reduced the incidence of mating of virgin females in treated plots relative to those in the control plots. Pheromone-baited trap catches were lowered on average by 96%, suggesting a high level of disruption. Average larval density on tree trunks was significantly lower in the pheromone-treated plots than in the untreated control plots. The mean percentage of Chinese scholar-tree petioles infested with first- and second-generation larvae, and seed pods infested with third-generation larvae was significantly greater in untreated control plots than in pheromone-treatment plots. These results suggest that disruption of pheromone-based communication in C. trasias is prospective, with synthetic sex pheromone on trees in urban environments.     

Identification of components of the female sex pheromone of the potato tuber moth, Scrobipalpopsis solanivora

The sex pheromone produced by virgin female S. solanivora moths has been shown to contain (E)-3-dodecenyl acetate with approximately 2% of the Z isomer by electroantennography and gas chromatography. In the field, traps baited with (E)-3-dodecenyl acetate alone or in combination with 1% or 2% of the Z isomer caught at least as many male S. solanivora moths as those baited with virgin female moths, and there was some evidence that addition of 5% of the Z isomer reduced catches.

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Résumé S. solanivora est l'un des plus importants lépidoptères détruisant les pommes de terre en Amérique Centrale. L'analyse par chromatographie en phase gazeuse (GC) des produits obtenus par lavage de l'ovipositeur de femelles vierges, associée à des électro-anténnogrammes (EAG) a révélé un composé actif unique en EAG. Les durées de rétention pour ce constituant correspondaient à celles des acétates monoinsaturés à 12 carbones, et les analyses sur colonne GC liées avec une phase liquide cristal ont montré un pic principal correspondant à l'acétate (E)-3-dodécénul et un pic secondaire, correspondant à l'isomère Z, et au niveau de 2,5% du pic principal. L'acétate dodécyl a aussi été décelé en quantités variables, approximativement 10% du pic principal.Dans la nature, des pièges contenant de l'acétate (E)-3-dodécényl, seul ou mélangé avec 1 ou 2% de l'isomère Z, ont capturé autant des mâles de S. solanivora que des pièges contenant des femelles vierges, et certaines indications montrent que l'addition de 5% de l'isomère Z réduit les captures.

     

Pheromone puffs suppress mating by Plodia interpunctella and Sitotroga cerealella in an infested corn store

The efficacy of pheromone mating disruption was investigated in a 7×6×3 m corn storage room harboring a high population density of Indian meal moth, Plodia interpunctella (Hübner) and Angoumois grain moth, Sitotroga cerealella (Olivier). Pheromones were released from a controlled release dispenser, the metered semiochemical timed release system (MSTRS^TM) at emission rates of 0.6 g min^–1 (Z9,E12:14:Ac for Indian meal moth) and 0.2 g min^–1 (Z7,E11-16:Ac for Angouimois grain moth). Mating disruption efficacy was evaluated using three parameters: male capture in pheromone traps, visual examination of mating behavior, and the incidence and frequency of mating as measured by spermatophores. In three trials, comparisons were made between data collected before pheromone treatment and during treatment. Disruption of pheromone source location by males averaged 70% and 40% for P. interpunctella and S. cerealella, respectively, in the three trials. In addition, reduced levels of copulation by both species were recorded during pheromone treatment. More importantly, significant reductions were recorded in the incidence and frequency of mating by females of both species collected during the treatment period. While 85% of P. interpunctella females collected before pheromone treatment in three trials had mated at least once, only 50% of the females collected during treatment had mated. The mean number of matings, as measured by spermatophores, ranged between 0.8–1.1 and 0.5–0.7 before and during pheromone treatment, respectively. Similarly, a 20–30% reduction in the proportion of mated S. cerealella females was recorded during pheromone treatment. In the three trials, mean number of spermatophores per S. cerealella female averaged 1.0 and 0.7 during the pretreatment and treatment periods, respectively. Additional tests conducted in small boxes also recorded significant mating disruption of both species.     

Models for mating disruption by means of pheromone for insect pest control

Models are presented to investigate the population dynamic behavior of a pest population with the release of pheromone for mating disruption. Three mechanisms of mating disruption are considered: (i) confusion of males, (ii) competition with female pheromone trails yielding false trail following, (iii) emigration of males prior to mating. In addition, several refinements to confusion are considered. Confusion and emigration of males were found to be very similar both quantitatively and dynamically; also, a combination of both mechanisms was very little more efficient than either one separately. False trail following is difficult to compare with the other two, since competition with wild females is involved and thus the total population size enters the equations. Density dependence of the action of pheromones results in some cases in which mating disruption cannot control the pest population. Similarly, aggregation of the pest population decreases the efficiency of the method unless the pheromone action is density independent. Delayed mating of females makes control easier, and may constitute one mechanism for mating disruption.     

Gypsy moth mating disruption in open landscapes

1 Aerial applications of Disrupt II, a plastic laminated flake formulation containing a racemic form of the gypsy moth sex pheromone, disparlure, achieved > 99% reduction of mating among females on individual, isolated trees surrounded by an area cleared of trees.
2 These results support the use of mating disruption to eradicate isolated gypsy moth populations in open landscapes, such as parks, residential areas and commercial settings.
3 Mating success in both treated and untreated areas varied with the initial distance between males and females. When the initial distance between males and females was < 5 cm in an area receiving a dosage of 37.5 g of racemic disparlure per ha, mating success was reduced by 27% compared with a similar deployment in an untreated area. Mating was eliminated in areas treated at the same dosage when males and females were initially deployed 1 m apart but on separate trees.
4 This suggests that mating disruption may not be an effective tactic for gypsy moth eradication in cases where the infestation is concentrated on a small number of trees and males and females are in close proximity in space and time.     

Mating disruption in Agrotis segetum monitored by harmonic radar

The long-range, pheromone-mediated, flight behaviour of male moths under natural and mating disruption conditions was monitored by means of harmonic radar. Individual male turnip moths, Agrotis segetum (Denis & Schiffermüller) (Lepidoptera: Noctuidae), tagged with radar transponders, were released and tracked in plots with or without disruptive doses of sex pheromone. In addition, male attraction to pheromone-baited traps and mating of calling females in treated and untreated plots was investigated. High doses of a four-component pheromone blend reduced trap catch by 79% and mating of females by 62% when compared with control plots in pre-radar experiments. Surprisingly, this effect was not associated with any pronounced differences in flight behaviour of males between a treatment and a control plot as revealed by harmonic radar recordings. In total, 20 flight tracks from a control plot and 22 flight tracks from a treatment plot were analysed. Moths could be followed for up to 77 min, corresponding to a track length of 7350 m. Mean ground speed ranged from 0.7 m s^–1 to 5.4 m s^–1. There was a strong trend (P = 0.06) for a greater number of male orientations to traps from downwind in the control field compared to the treatment field. Many flight tracks were fragmented due to radar shadow. Advantages and constraints using harmonic radar to study the pheromone-mediated flight behaviour of nocturnal moths are discussed.     

Mechanisms of communication disruption by pheromone in the control of Lepidoptera: a review

ABSTRACT. Five possible mechanisms involved in the disruption of phero-mone-mediated behaviour in the control of lepidopterous pests are discussed. The various techniques used in the field, laboratory investigations of such mechanisms, and possible limitations in the application of such studies, are reviewed.