Plant volatile compounds shorten reaction time and enhance attraction of the codling moth (Cydia pomonella) to codlemone

BACKGROUND: The codling moth is the most serious pest of deciduous tree fruit (apples, pears, crabapples, walnuts, quince) worldwide. The high frequency of insecticide treatments per season has resulted in breakdown of codling moth control owing to insecticide resistance. As an alternative, integrated pest management includes mating disruption to achieve population suppression in orchards. Under this scheme, the sex pheromone of the codling moth, (E, E)‐8,10‐dodecadien‐1‐ol (codlemone), is released from dispensers in crops to hinder mating by luring males. Increasing the attractiveness of codlemone formulations to codling moth males can be regarded as a key to increasing the efficacy of mating disruption. With this aim, the effects of adding plant volatiles on the behavioural responses of codling moth males to codlemone were tested. RESULTS: Adding R(+)‐limonene, linalool, (E)‐β‐farnesene or ethyl (E, Z)‐2,4‐decadienoate to codlemone significantly increases the proportion of males flying to the pheromone source in a wind tunnel. The response level is equivalent to that of males responding to females releasing codlemone. Using real‐time recordings, it is shown how these four plant products also shorten the response time of males to codlemone under the behavioural criteria time to activation, time till upwind flight is induced and time to pheromone source contact. CONCLUSION: Shortening the response time and increasing source location by males of dispensers releasing codlemone with R(+)‐limonene, linalool, (E)‐β‐farnesene or ethyl (E, Z)‐2,4‐decadienoate added would enhance mating disruption through better engagement of males with dispensers, to the detriment of females. Copyright © 2011 Society of Chemical Industry     

Mobile mating disruption of light-brown apple moths using pheromone-treated sterile Mediterranean fruit flies

BACKGROUND: Public opposition to aerial application of sex pheromone for mating disruption of light‐brown apple moth (LBAM), Epiphyas postvittana (Walk.), in California stopped its further use in the ca $ 74 million eradication programme in 2008, underscoring the need for other eradication tactics. It is demonstrated that pheromone‐treated sterile Mediterranean fruit flies (medflies), Ceratitis capitata Wied., can disrupt communication in male moths. RESULTS: Medflies topically dosed with moth pheromone (E)‐11‐tetradecenyl acetate showed a no observed effect level (NOEL) of ～10 µg fly^?1, with increasing toxicity from 30 to 100 µg fly^?1. Greater potency and longevity of attraction and lower mortality were achieved using microencapsulated pheromone. Releases of 1000 pheromone‐treated medflies ha^?1 prevented male moth catch to synthetic lures in treated 4 ha plots for 1 day in suburban Perth, Australia. Releases of ca 3000 pheromone‐treated medflies ha^?1 disrupted catch to single female moths in delta traps, and to synthetic pheromone lures. Percentage disruption on the first four nights was 95, 91, 82 and 85%. CONCLUSIONS: Disruption of moth catch using pheromone‐treated medflies is a novel development that, with future improvement, might provide a socially acceptable approach for application of the insect mating disruption technique to control invasive insects in urban environments. Adequacy of payload and other issues require resolution. Copyright © 2011 Society of Chemical Industry     

Electrophysiological and behavioural responses of Pityophthorus pubescens (Coleoptera: Scolytinae) to (E,E)‐α‐farnesene, (R)‐(+)‐limonene and (S)‐(−)‐verbenone in Pinus radiata (Pinaceae) stands in northern Spain

BACKGROUND: Some twig beetles in the genus Pityophthorus (Coleoptera: Scolytinae) may vector pitch canker disease Fusarium circinatum (Niremberg & O'Donnell) of Pinus spp. (Pinaceae). Because Pityophthorus pubescens (Marsh.) has been found to be associated with F. circinatum in the Basque Country (northern Spain), various experiments were conducted to assess the beetle's behavioural responses to (E, E)‐α‐farnesene, (R)‐(+)‐limonene and (S)‐(?)‐verbenone to develop a potential inhibitor to host attraction. These experiments comprise electroantennographic and double‐choice olfactometer tests, as well as field assays in Pinus radiata D. Don stands. RESULTS: Both sexes of P. pubescens showed similar electroantennographic responses to different doses (from 1 ng to 1 µg in decadic steps) of each individual compound, with depolarisations to (S)‐(‐)‐verbenone (100 ng) being similar to those of the aggregation pheromone (+)‐trans‐pityol. In olfactometer assays, both sexes were significantly attracted to (+)‐trans‐pityol, but the attraction was reduced when increasing amounts of the chemicals were added to the pheromone. Particularly relevant was the repellent effect induced by (S)‐(?)‐verbenone at 1 ng dose and higher. In the field, (E, E)‐α‐farnesene, (R)‐(+)‐limonene and (S)‐(?)‐verbenone reduced significantly the number of beetles attracted to (+)‐trans‐pityol and racemic trans‐pityol, with (S)‐(?)‐verbenone being the most effective. CONCLUSIONS: (S)‐(?)‐Verbenone showed an interesting potential for use in the protection of P. radiata stands. A potentially effective strategy, which could be implemented in further, more in‐depth studies, could involve the use of this semiochemical as repellent and (+)‐trans‐pityol‐baited traps as attractant in a ‘push‐pull’ strategy. Copyright © 2012 Society of Chemical Industry     

Development of single-dispenser pheromone suppression of Epiphyas postvittana, Planotortrix octo and Ctenopseustis obliquana in New Zealand stone fruit orchards

BACKGROUND: Pheromones of two native leafrollers of economic importance to the New Zealand horticulture industry, Planotortrix octo [(Z)‐8‐tetradecenyl acetate and tetradecyl acetate] and Ctenopseustis obliquana [(Z)‐5‐tetradecenyl acetate and (Z)‐8‐tetradecenyl acetate], were reinvestigated and combined with pheromone of Epiphyas postvittana [light‐brown apple moth, (E)‐11‐tetradecenyl actetate and (E, E)‐9,11‐tetradecen‐1‐yl acetate] to develop a single dispenser for mating disruption of three pest species for integrated pest management. RESULTS: Additional compounds identified from pheromone gland extracts were characterised as repellents for P. octo. However, for C. obliquana from Central Otago, a change in ratio of (Z)‐5‐tetradecenyl acetate and (Z)‐8‐tetradecenyl acetate and the addition of three compounds found in the gland (dodecyl acetate, tetradecyl acetate and hexadecanal) led to a significant improvement in catch over previous lures. Males from Central Otago showed antennal electrophysiological responses to hexadecanal, unlike C. obliquana from Auckland, which did not. Three multiple‐species disruption blends were devised in a single dispenser to target E. postvittana, P. octo and C. obliquana. Disruption of traps was recorded in single‐tree replicates with all three blends, but the five‐component blend was overall most effective at disruption and was deployed area wide in commercial orchard plots. CONCLUSIONS: Deployment of single dispensers into commercial stone fruit orchards led to disruption of trapping for the three species and measurable reductions in insecticide use in cherries, peaches and nectarines without increased fruit damage (assessed in apricots). Copyright © 2011 Society of Chemical Industry     

Combined use of a synthetic trail pheromone and insecticidal bait provides effective control of an invasive ant

BACKGROUND: Except for sex pheromones, use of pheromones in pest management has been largely unexplored. A high concentration of trail pheromone disrupts ant trail following and foraging, and thus synthetic trail pheromone can be a novel control agent for pest ants. In this study, a year‐long treatment of small areas (100 m² plots of urban house gardens) with synthetic trail pheromone, insecticidal bait or both was conducted to develop a novel control method of the invasive Argentine ant Linepithema humile (Mayr). RESULTS: The ant population could be maintained lower than or similar to the initial level only by combined treatment with synthetic trail pheromone and insecticidal bait. Actually, the ant population was nearly always lowest in combination treatment plots. Throughout the study period, the ant population in plots treated with either one of synthetic trail pheromone or insecticidal bait remained similar to no‐treatment plots. CONCLUSIONS: Combination treatment may be a more effective and environmentally friendly method for controlling invasive ants than conventional methods. Extermination of ants by insecticidal bait and inhibition of re‐infestation by pheromone may be the mechanism of the combination effect. This is the first study to show a significant effect of synthetic trail pheromone on ant population. Copyright © 2011 Society of Chemical Industry     

Studies on the development of a mating disruption system to control the tomato leafminer, Tuta absoluta Povolny (Lepidoptera: Gelechiidae)

BACKGROUND: The tomato leafminer (Tuta absoluta Povolny) has rapidly colonised the whole Mediterranean and South‐Atlantic coasts of Spain, and it has become a key problem in both outdoor and greenhouse crops. New control methods compatible with biological control are required, and mating disruption appears to be a perfect method in current agriculture, as it is an environmentally friendly and residue‐free technique. IPM packages tested have included the use of pheromones to detect populations, but there has not been much previous research on mating disruption of T. absoluta. In this work, pheromone doses varying from 10 to 40 g ha^?1, emitted at a constant rate over 4 months, were tested in greenhouses with different levels of containment in order to evaluate the efficacy of mating disruption on T. absoluta. RESULTS: Trials on containment level revealed that the flight of T. absoluta was satisfactorily disrupted with an initial pheromone dose of 30 g ha^?1, and levels of damage did not significantly differ from those in reference plots with insecticide treatments. Later efficacy trials confirmed previous experiences, and release studies showed that control of damage and flight disruption were taking place when releasing at least 85 mg pheromone per ha per day. CONCLUSION: Effective control using pheromone application against T. absoluta can be achieved, in greenhouses with high containment levels, for 4 months, with initial doses of 30 g ha^?1. Further research must be conducted in order to evaluate the prospect of outdoor application of mating disruption systems. Copyright © 2011 Society of Chemical Industry     

红火蚁信息素及其在化学防治中的应用研究进展

文章介绍了红火蚁的危害特征,分析了目前国内外红火蚁防治的主要方法,对利用化学信息素类物质防治红火蚁的研究方法及进展进行了综述;通过借鉴化学信息素在其他害虫防治中的应用,重点分析了化学信息素在红火蚁防治中的必要性和可能性,对红火蚁相关信息素的特点和化学结构进行了详细描述,并介绍了相关化学信息素的合成方法,揭示了信息素类物质在红火蚁综合防治中的重要性及优越性。     

粘虫雌蛾性信息素特征成分鉴定及其不同配比的室内引诱效果

为确定粘虫Mythimna separata(Walker)雌蛾的性信息素特征成分及其不同配比的室内引诱效果,采用气相色谱-质谱和气相色谱-触角电位联用技术检测了雌蛾性腺浸提液,并利用Y型嗅觉仪测定了粘虫雄蛾对不同配比性信息素特征成分的选择反应。结果显示,从粘虫的求偶雌蛾性腺浸提液中可分离到顺-11-十六碳烯醛、十六碳醛和顺-11-十六碳烯醇3种特征成分,在色谱柱中的保留时间依次为15.82、16.06和17.27 min,含量分别为3.37、1.83和0.10 ng,比例约为34∶18∶1。无论是天然存在于雌蛾性腺还是人工合成的顺-11-十六碳烯醛均能够激发雄蛾的电生理反应。顺-11-十六碳烯醛、十六碳醛和顺-11-十六碳烯醇不同配比对雄蛾表现出不同的引诱活性,最大引诱率达87%,极显著高于对照溶剂石蜡油对雄蛾的引诱率。表明顺-11-十六碳烯醛、十六碳醛和顺-11-十六碳烯醇为中国粘虫种群的雌蛾性信息素特征成分,且其不同配比对雄蛾有不同的引诱活性。     

Field evaluation of synthetic sex pheromone traps for the cocoa mirid Sahlbergella singularis (Hemiptera: Miridae)

BACKGROUND: Field trapping experiments were conducted to evaluate the attractiveness of five different pheromone blends as well as the impact of trap design on attractiveness towards cocoa mirids, Sahlbergella singularis Hagl. and Distantiella theobroma (Dist.), in Cameroon. RESULTS: A total of 361 adults of S. singularis (359 males and two females) were caught. The highest numbers of mirids were found in traps with pheromone blends that combined a monoester and a diester, compared with traps with the diester or the monoester individually and control traps with no pheromone. Rectangular traps caught significantly more mirids compared with delta traps. The mean number of 5.1 mirids trap^?1 year^?1 caught in rectangular traps was significantly higher compared with the 1.8 mirids trap^?1 year^?1 for the delta traps. CONCLUSION: The data revealed that rectangular traps containing pheromone blends combining both the monoester and the diester have a good potential to lure and trap adult males of S. singularis on cocoa farms. The pheromone blends used were specific for S. singularis, and the use of pheromone traps appears to be a promising strategy for incorporation into integrated pest management strategies for the monitoring or even the control of S. singularis in cocoa plantations. Copyright © 2011 Society of Chemical Industry     

Mating disruption of California red scale,Aonidiella aurantii Maskell (Homoptera: Diaspididae), using biodegradable mesoporous pheromone dispensers

BACKGROUND: The control of California red scale, Aonidiella aurantii (Maskell), has encountered many difficulties, which has raised interest in alternative control methods. Up to now, the A. aurantii sex pheromone has been used only for monitoring. In a previous work the authors described a biodegradable mesoporous pheromone dispenser for mating disruption. To verify the efficacy of these dispensers, three field trials were conducted, and the results are shown in this paper. RESULTS: The study of the release profile of these dispensers revealed a mean pheromone emission value of 269 µg day^?1 and levels of residual pheromone of 10% at the end of 250 days. During the second flight, an A. aurantii male catch reduction of 98% was achieved in the mating disruption plot of trial 1, 93.5% in trial 2 and 76.7% in trial 3. During the third flight, reductions were 94.1, 82.9 and 68.1% in trials 1, 2 and 3 respectively. Considering damaged fruit with more than five scales, reductions of about 80 and 60% were obtained in the mating disruption plots of trials 2 and 3, respectively, compared with an untreated plot, and a reduction of about 70% in trial 1 compared with an oil‐treated plot. CONCLUSION: Mating disruption has been found to be an efficient technique to control this pest, working equally well to a correctly sprayed oil treatment. Further studies are needed to improve the determination of the time of dispenser application and evaluate the effects of the pheromone on natural enemies. Copyright © 2010 Society of Chemical Industry     

Acaricidal activities of the active component of Lycopus lucidus oil and its derivatives against house dust and stored food mites (Arachnida: Acari)

BACKGROUND: Recent studies have focused on materials derived from plant extracts as mite control products against house dust and stored food mites because repeated use of synthetic acaricides had led to resistance and unwanted activities on non‐target organisms. The aim of this study was to evaluate the acaricidal activity of materials derived from Lycopus lucidus against Dermatophagoides farinae, D. pteronyssinus and Tyrophagus putrescentiae. RESULTS: The LD₅₀ values of L. lucidus oil were 2.19, 2.25 and 8.45 µg cm^?2 against D. farinae, D. pteronyssinus and T. putrescentiae. The acaricidal constituent of L. lucidus was isolated by chromatographic techniques and identified as 1‐octen‐3‐ol. In a fumigant method against D. farinae, the acaricidal activity of 1‐octen‐3‐ol (0.25 µg cm^?2) was more toxic than N,N‐diethyl‐m‐toluamide (DEET) (36.84 µg cm^?2), followed by 3,7‐dimethyl‐1‐octen‐3‐ol (0.29 µg cm^?2), 1‐octen‐3‐yl butyrate (2.32 µg cm^?2), 1‐octen‐3‐yl acetate (2.42 µg cm^?2), 3,7‐dimethyl‐1‐octene (9.34 µg cm^?2) and benzyl benzoate (10.02 µg cm^?2). In a filter paper bioassay against D. farinae, 1‐octen‐3‐ol (0.63 µg cm^?2) was more effective than DEET (20.64 µg cm^?2), followed by 3,7‐dimethyl‐1‐octen‐3‐ol (1.09 µg cm^?2). CONCLUSION: 1‐Octen‐3‐ol and 3,7‐dimethyl‐1‐octen‐3‐ol could be useful as natural agents for the management of three mite species. Copyright © 2011 Society of Chemical Industry     

Diurnal variation of walnut tree volatiles and electrophysiological responses in Cydia pomonella (Lepidoptera: Tortricidae)

BACKGROUND: In recent years, many studies have been carried out on the behavioural and electrophysiological responses of Cydia pomonella (L.) to host volatile emissions, to find alternative attractants to the sex pheromone for pest monitoring. These studies have focused on apple and pear, and very little has been done on walnut. In the present work, the diurnal and seasonal variation in walnut volatile emissions and the electrophysiological response of C. pomonella have been studied. RESULTS: Ninety compounds were detected in walnut emissions, mainly monoterpenes and sesquiterpenes. The most abundant compound was β‐pinene, which, together with (Z)‐3‐hexenyl acetate, (E)‐β‐ocimene, limonene, germacrene D, 1,8‐cineole, sabinene, (E)‐β‐farnesene, (E)‐β‐caryophyllene, β‐myrcene and β‐phellandrene, constituted between 81.9 and 90.5% of the total chromatographic area. Differences between seasonal periods were significant for 39 compounds, and between daytimes for 14 compounds. Discernible and consistent EAD responses were detected to 11 walnut‐origin compounds, and confirmed with synthetics to seven of them. Except for alloocimene, pinocarvone and caryophyllene oxide, all these compounds are also emitted by apple. CONCLUSION: Walnut volatile emissions differ widely from apple ones, but both share many compounds that are EAD‐active in C. pomonella. However, among EAD‐active compounds there are three walnut‐specific ones, which should be further tested in behavioural assays. Copyright © 2008 Society of Chemical Industry     

Effect of temperature,organic amendment rate and moisture content on the degradation of 1,3‐dichloropropene in soil

1,3‐Dichloropropene (1,3‐D), which consists of two isomers, (Z)‐ and (E)‐1,3‐D, is considered to be a viable alternative to methyl bromide, but atmospheric emission of 1,3‐D is often associated with deterioration of air quality. To minimize environmental impacts of 1,3‐D, emission control strategies are in need of investigation. One approach to reduce 1,3‐D emissions is to accelerate its degradation by incorporating organic amendments into the soil surface. In this study, we investigated the ability of four organic amendments to enhance the rate of degradation of (Z)‐ and (E)‐1,3‐D in a sandy loam soil. Degradation of (Z)‐ and (E)‐1,3‐D was well described by first‐order kinetics, and rates of degradation for the two isomers were similar. Composted steer manure (SM) was the most reactive of the organic amendments tested. The half‐life of both the (Z)‐ and (E)‐isomers in unamended soil at 20 °C was 6.3 days; those in 5% SM‐amended soil were 1.8 and 1.9 days, respectively. At 40 °C, the half‐life of both isomers in 5% SM‐amended soil was 0.5 day. Activation energy values for amended soil at 2, 5 and 10% SM were 56.5, 53.4 and 64.5 kJ mol^?1, respectively. At 20 °C, the contribution of degradation from biological mechanisms was largest in soil amended with SM, but chemical mechanisms still accounted for more than 58% of the (Z)‐ and (E)‐1,3‐D degradation. The effect of temperature and amendment rate upon degradation should be considered when describing the fate and transport of 1,3‐D isomers in soil. Use of organic soil amendments appears to be a promising method to enhance fumigant degradation and reduce volatile emissions. Published in 2001 for SCI by John Wiley & Sons, Ltd     

Toxicity of formic acid to red imported fire ants, Solenopsis invicta Buren

BACKGROUND: Ants often compete with other ants for resources. Although formic acid is a common defensive chemical of formicine ants, it does not occur in any other subfamilies in Formicidae. No information on toxicity of formic acid to red imported fire ants, Solenopsis invicta, is available. This study examined its contact and fumigation toxicity to S. invicta in the laboratory. RESULTS: In a contact toxicity bioassay, 24 h LD₅₀ values of formic acid for workers ranged from 124.54 to 197.71 µg ant⁻¹. Female alates and queens were much less sensitive to formic acid than workers. At a concentration of 271.72 µg ant⁻¹, which killed 81.09 ± 16.04% of workers, the 24 h mortality was up to 39.64% for female alates and 38.89% for queens. In fumigation bioassays, 24 h LC₅₀ values ranged from 0.26 to 0.50 µg mL⁻¹ for workers, 0.32 µg mL⁻¹ for male alates and 0.70 µg mL⁻¹ for female alates. Complete mortality (100%) in queens occurred 24 h after they had been exposed to 1.57 µg mL⁻¹ of formic acid. At a concentration of 2.09 µg mL⁻¹, KT₅₀ values ranged from 23.03 to 43.85 min for workers, from 37.84 to 58.37 min for male alates, from 86.06 to 121.05 min for female alates and from 68.00 to 85.92 min for queens. CONCLUSION: When applied topically, formic acid was significantly less toxic than bifenthrin to red imported fire ants. Although its fumigation toxicity was lower than that of dichlorvos, formic acid had about an order of magnitude higher toxicity to S. invicta than to other insects studied so far. It may be worth investigating the use of formic acid for managing imported fire ants. Published 2012 by John Wiley & Sons, Ltd.     

Contact and fumigant activities of constituents of Foeniculum vulgare fruit against three coleopteran stored‐product insects

The insecticidal activities of materials derived from the fruit of fennel, Foeniculum vulgare, against adults of Sitophilus oryzae, Callosobruchus chinensis and Lasioderma serricorne were examined using direct contact application and fumigation methods. The biologically active constituents of the Foeniculum fruits were characterized as the phenylpropenes (E)‐anethole and estragole, and the monoterpene (+)‐fenchone, by spectroscopic analysis. Responses varied with insect species, compound, dose and exposure time. In a filter paper diffusion test, estragole at 0.168 mg cm^?2 caused 91% mortality to S oryzae adults within 1 day after treatment (DAT), whereas (+)‐fenchone and (E)‐anethole gave over 90% mortality at 2 and 4 DAT, respectively. Against C chinensis adults, all test compounds revealed potent insecticidal activities at 0.021 mg cm^?2 at 2 DAT. Against L serricorne adults at 0.105 mg cm^?2, (E)‐anethole gave 100% mortality at 1 DAT, whereas 90 and 60% mortality at 4 DAT was achieved with estragole and (+)‐fenchone, respectively. In a fumigation test, the test compounds were much more effective against adults of S oryzae, C chinensis and L serricorne in closed cups than in open ones, indicating that the insecticidal activity of test compounds was largely attributable to fumigant action. As naturally occurring insect‐control agents, the F vulgare fruit‐derived materials described could be useful for managing field populations of S oryzae, C chinensis and L serricorne. © 2001 Society of Chemical Industry     

Higher-tier assessment of the potential for groundwater issues due to the use of 1,3-D soil fumigant; evaluation of the active ingredient, metabolites and potentially related chlorinated compounds

BACKGROUND: 1,3‐Dichloropropene (1,3‐D, CAS No. 542‐75‐6) is a broad‐spectrum soil fumigant used to control numerous species of soilborne plant‐parasitic nematodes. 1,3‐D consists of two isomers, (Z)‐ and (E)‐1,3‐D. There are a number of low‐level chlorinated compounds that could potentially be produced as a part of the 1,3‐D manufacturing process. 1,3‐D and its metabolites, as well as potentially related chlorinated compounds, represent potential groundwater contaminants. RESULTS: This study has investigated the hydrolytic stability, under biotic and abiotic conditions in the laboratory, of an extensive representative list of 1,3‐D and potentially related chlorinated compounds in order to predict their environmental fate. All of these compounds showed intrinsic hydrolytic instability under both abiotic and biotic test conditions. Furthermore, a monitoring programme was carried out. Twenty‐five wells were monitored in five Italian regions characterised by historical and existing use of 1,3‐D. The parent compound, its two major metabolites and potentially related chlorinated compounds were not detected in the well water at > 0.1 µg L^?1 at any sampling location. CONCLUSION: The soil fumigant (E,Z)‐1,3‐D, its metabolites and potentially related chlorinated compounds constitute a low risk to groundwater. Copyright © 2011 Society of Chemical Industry     

Enhanced repellency of binary mixtures of Zanthoxylum piperitum pericarp steam distillate or Zanthoxylum armatum seed oil constituents and Calophyllum inophyllum nut oil and their aerosols to Stomoxys calcitrans

BACKGROUND: The repellency to stable fly, Stomoxys calcitrans (L.), of Zanthoxylum piperitum (L.) DC pericarp steam distillate (ZP‐SD), Zanthoxylum armatum DC seed oil (ZA‐SO) and their constituents alone or in combination with Calophyllum inophyllum L. nut oil (CI‐NO), as well as six aerosol formulations containing ZP‐SD or ZP‐SO and CI‐NO, was compared with that of a synthetic repellent, DEET, using an exposed human hand bioassay. RESULTS: At 0.20 mg cm^?2, ZP‐SD treatments resulted in 91 and 68% repellency following 30 and 60 min exposure respectively, while DEET gave 100 and 84% repellency. ZA‐SO was less effective than ZP‐SD. At 0.2 mg cm^?2, the most active constituents, cuminaldehyde, cuminyl alcohol, limonene and methyl cinnamate, gave 82, 74, 74 and 64% repellency at 30 min respectively, but DEET gave 100 and 87% repellency at 30 and 60 min. An increase in effectiveness and duration of repellency was produced by binary mixtures of ZP‐SD, ZA‐SO or bioactive constituents (each 0.01 mg cm^?2) and CI‐NO (0.99 mg cm^?2). The repellency of aerosols containing 2.5% ZP‐SD or 2.5% ZA‐SO and 2.5% CI‐NO was comparable with that of 5% DEET aerosol. CONCLUSION: Mixtures formulated from ZP‐SD, ZA‐SO or bioactive constituents and CI‐NO could be useful as potential repellents for the control of stable fly populations in light of global efforts to reduce the level of highly toxic synthetic repellents. Copyright © 2010 Society of Chemical Industry     

(Z)-3-hexenyl acetate and 1-undecanol increase male attraction to sex pheromone trap in Grapholita molesta (Busck) (Lepidoptera: Tortricidae)

The effects of host-plant volatiles (HPVs) on male oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), and response to sex pheromone trap were studied in a pear orchard. Two HPVs compounds, (Z)-3-hexenyl acetate and 1-undecanol, combined with sex pheromone of G. molesta in traps were tested. The results showed that most of the male moths were captured in the traps baited with the sex pheromone combined with these two HPVs compounds than by the pheromone alone. Also, more males were captured by the trap containing pheromone plus (Z)-3-hexenyl acetate than by the one containing 1-undecanol. It appeared that these HPVs act as sex pheromone synergists to enhance the attraction of male G. molestato pheromone traps, since males were not captured in the traps baited only with (Z)-3-hexenyl acetate and/or 1-undecanol.     

Life history parameters and scale-cover surface area of Aonidiella aurantii are altered in a mating disruption environment: implications for biological control

BACKGROUND: In recent years, environmentally safe measures to control the California red scale (CRS), Aonidiella aurantii (Maskell), have been successfully implemented. These measures include mating disruption (MD) and biological control. The goal of this study was to examine the effect of high concentrations of the CRS sex pheromone on its life history parameters and scale‐cover surface area under controlled laboratory conditions. RESULTS: The developmental time of both males and females of CRS increased with exposure to airborne pheromone. MD had an effect on both the total number of progeny and on the crawler production period for females. Accordingly, demographic parameters such as net fecundity (R₀) and intrinsic rate of increase (r_m) were significantly lower in the pheromone‐treated populations. The largest scale‐cover surface areas were observed in the CRS reared in the pheromone environment. CONCLUSION: A clear influence of airborne pheromone on the biology of CRS has been demonstrated. In addition to the classical mating disruption benefits of this technique, additional benefits, such as increase in the duration of exposure to natural enemies and increase in size, which benefits some species of parasitoids, have been confirmed. Copyright © 2012 Society of Chemical Industry     

Effects of reservoir dispenser height on efficacy of mating disruption of codling moth (Lepidoptera: Tortricidae) in apple

BACKGROUND: The effect of varying the height of reservoir dispensers for mating disruption of codling moth, Cydia pomonella (L.), was investigated. The goal was to improve the effectiveness of C. pomonella mating disruption through improved understanding of adult distribution within the tree canopy and the impact of pheromone dispenser placement on disruption. Two dispensers per tree were placed at 2 m and 4 m and/or one dispenser at each height on the tree at a label rate of 1000 units ha^?1. Monitoring traps and tethered female moths were deployed in plots at 2 and 4 m heights to assess treatment effects by catches or matings respectively. RESULTS: Fewest male moths were captured with all dispensers placed at 4 m. Female mating was lowest, and with least variation between females tethered at 2 and 4 m, when dispensers were placed simultaneously at 2 and 4 m (28% mated). Mating was 32% with both dispensers at 4 m, 38% with both dispensers at 2 m and 46% in the no disruption control. Mating was highest across treatments when females were tethered at 2 m and dispensers placed at 4 m (40%), and when females were tethered at 4 m with dispensers placed at 2 m (46%). CONCLUSION: Traps at 4 m in trees captured more male moths than traps at 2 m, regardless of disruption dispenser positioning. Female mating was lowest when dispensers were placed simultaneously at 2 and 4 m, suggesting that current recommendations for placement of reservoir dispensers in tree crowns may be suboptimal. Copyright © 2011 Society of Chemical Industry