Fourth Conference of West African Cocoa Entomologists,Legon, December 1974

Abstract

Hollow‐fibre, laminate‐flake and microencapsulated formulations of the synthetic sex pheromone (Z,Z) and (Z,E)‐7–11‐hexadecadienyl acetate of Pectinophora gossypiella (Saunders) were applied aerially in large scale trials in the Delta region of Egypt in 1985. 100 ha blocks of cotton were treated at regular intervals throughout the season as the only means of controlling the pest and compared with a 100 ha block of cotton sited in the same locality which was treated aerially with conventional insecticide spray applications. Comparisons of numbers of infested bolls, open boll counts and yields of seed cotton showed that adequate levels of control were achieved with all three pheromone formulations which were at least as effective as the insecticide sprays. The costs of the pheromone formulations and their aerial application also compared favourably with the insecticide programme. Greater numbers of beneficial insects were recorded in the pheromone‐treated areas than in the insecticide treated area.     

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     

Effects of pheromone loading, dispenser age, and trap height on pheromone trap catches of the oriental fruit moth in apple orchards

The effects of field aging (0–28 days) and pheromone loading rate on the longevity of red rubber septa loaded with the sex pheromone blend of the oriental fruit mothGrapholita molesta (Busck), were evaluated in North Carolina apple orchards in 2002. Separate field tests examined the influence of trap height and pheromone loading rate of rubber septa on trap catches of adultG. molesta males in an abandoned orchard. The loss of the major pheromone component, (Z)-8-dodecenyl acetate (Z8–12:OAc), from red rubber septa over a 4-week period exhibited a relatively constant release rate with 30, 100 and 300 μg pheromone. Trap catch was significantly higher in pheromone traps placed in the upper canopy than in those in the lower canopy. Pheromone traps baited with 100μg lures caught more moths compared with those loaded with 300 μg. There was no apparent relationship between pheromone trap catch and septa age, with trap catch appearing to be primarily a function ofG. molesta population density. http://www.phytoparasitica.org posting May 14, 2006.     

(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.     

Field trial on the effects of the herbicide MCPA on ixodid ticks

Abstract

Studies were conducted to develop a pheromone‐trap monitoring system for the sweet potato weevil, Cylas formicarius (Fabricius), in sweet potato, Ipomoea batatas (L.) Lam., fields in four states: Florida, Louisiana, North Carolina, and Texas. The present studies examined the attractiveness of sex pheromone synthesized by two sources (USDA and AgriSense) and pheromone of different purities (75–99%) to weevils in the field. In all but one trial, weevil counts did not differ between traps baited with pheromone from the two sources for each of two doses (10 and 100 μg). Percentages of weevils caught per replicate per sample date were not consistently positively correlated with purity (significant in four of 10 trials); however, slope estimates were steeper in regions with lower trap counts (North Carolina and Louisiana) than in those with higher trap counts (Florida). Because the pheromone will be used to monitor weevils In both weevil‐free and weevil‐infested regions, the use of pheromone with a purity level >99% is most appropriate. The importance of these data in pheromone‐trap monitoring programmes for this weevil worldwide is discussed.     

Inhibition of pheromone action in Sesamia nonagrioides by Haloacetate analogues

The electrophysiological activity of some halogenated analogues of the major component of the sex pheromone of the corn stalk borer Sesamia nonagrioides Lef. (1) is presented. The analogues comprise a series of fluoro-, chloro- and bromoacetate analogues 4 – 10 as well as trifluoromethyl ketone 11. The fluoro derivatives 4 – 6 displayed remarkable electro-antennogram (EAG) intrinsic activities in comparison with the parent acetate 1, while the remaining analogues elicited significantly lower response. The compounds have also been tested as inhibitors of the sex pheromone perception in EAG and in the field. In the laboratory. fluoro analogues 4 – 6 were better inhibitors than chloro derivatives 7 – 9 , which in turn behaved similarly to the bromoacetate 10 . Trifluoromethyl ketone 11, however, was a poor inhibitor of the pheromone action. In the field, baits of mixtures of compounds 5 – 11 with the corn stalk borer pheromone in 10 :1 ratio inhibited the concomitant attraction of the clover cutworm moth Scotogramma irifolii Rott., while the difluoro analogue 5, trichloroacetate 9 and trifluoromethyl ketone 11 also diminished the number of catches of the armyworm Mythimna unipuncta Haw. The monofluoroacetate 4. trifluoro analogue 6 and bromo derivative 10 significantly disrupted the pheromone action of the corn borer, whereas trifluoromethyl ketone 11 synergistically increased the number of males attracted to the pheromone trap alone. Addition of 11 to baits containing the corn borer pheromone caught S. nonagrioides selectively with regard to the other habitat-sharing species M. unipuncta and S. trifolii.     

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     

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     

The Effects of Atrazine in Maize-Wheat Rotations

Abstract

Catches of male moths of the Egyptian cotton leafworm, Spodoptera littoralis (Boisd.), in light traps and pheromone traps were compared at an experimental site at Sakha (Kafr El-Sheikh Province, Egypt) between June and November 1976. The catches in the pheromone traps were generally higher than those in the light traps, although the difference ratio varied from month to month. It was concluded that pheromone traps provided a useful ecological tool for S. littoralis in Egypt.     

桃小食心虫成虫种群动态监测与防治指标

为明确桃小食心虫Carposina sasakii Matsumura成虫的种群动态变化,2002—2014年在陕西省礼泉县当地具有代表性的苹果园中,采用性诱剂诱捕器对桃小食心虫成虫的种群动态进行系统监测,并于2010年和2011年的7—8月桃小食心虫成虫盛发期,系统调查了成虫发生量与苹果着卵量的关系,建立基于性诱剂监测的桃小食心虫成虫防治指标。结果显示,苹果园桃小食心虫成虫的种群动态、始见期和终见期在年度之间差异很大,每年主要集中在6—8月发生;桃小食心虫成虫每年出现多次无规律的高峰,但第1代成虫高峰期发生的早晚与越冬代成虫高峰期出现的早晚有密切联系,即越冬代成虫高峰期出现早,则第1代成虫高峰期出现也就相对较早,且越冬代成虫发生量明显多于第1代成虫。性诱剂诱捕的成虫与卵果率之间呈极显著的对数关系,当以卵果率1%或2%为防治指标时,性诱剂诱捕器诱蛾量为8.3头/诱捕器·日或30.0头/诱捕器·日。     

Optimisation of the pheromone blend of the swede midge,Contarinia nasturtii,for monitoring

BACKGROUND: The swede midge, Contarinia nasturtii Kieffer, is a serious pest in crucifers. Its pheromone is a blend of (2S,9S)‐diacetoxyundecane, (2S,10S)‐diacetoxyundecane and (2S)‐acetoxyundecane. The pheromone is used in monitoring traps, and this study examines possible ways to optimise the traps. RESULTS: Two dispenser types were compared: polyethylene dispensers and cotton dispensers. Polyethylene dispensers attracted male C. nasturtii for more than 6 weeks, whereas cotton dispensers were attractive for only 2 weeks. All three pheromone components were important for attraction of male midges in the field. The importance of the stereoisomeric compositions of the pheromone compounds was also tested—both in the wind tunnel and in the field. In the case of 2,9‐diacetoxyundecane and 2‐acetoxyundecane, the non‐natural stereoisomers did not inhibit male C. nasturtii attraction, whereas one or both of the stereoisomers of 2,10‐diacetoxyundecane did. CONCLUSION: Pheromone traps with the synthetic pheromone in a 1:2:0.02 ratio emitted from PE dispensers were highly effective and long lasting. As the mixture of stereoisomers of 2,10‐diacetoxyundecane strongly inhibited attraction of male C. nasturtii while those of 2,9‐diacetoxyundecane and 2‐acetoxyundecane did not have any inhibitory effect, it is possible to produce traps that are effective and long lasting but cheaper to produce and maintain. Copyright © 2009 Society of Chemical Industry     

Mating disruption for the control of Aonidiella aurantii Maskell (Hemiptera: Diaspididae) may contribute to increased effectiveness of natural enemies

BACKGROUND: New directives on sustainable use of pesticides have encouraged research on efficient alternative pest control methods. In the case of the California red scale (CRS), Aonidiella aurantii (Maskell), this imperative, along with the many difficulties in controlling this pest, have led to the investigation of new approaches. Previously developed mating disruption (MD) dispensers, together with the augmentative releases of the parasitoid Aphytis melinus DeBach, are here considered as a combined strategy for use against A. aurantii. RESULTS: Efficacy of MD was demonstrated by a mean reduction of 80% in CRS male catches and a mean fruit damage reduction of 83% compared with the control. A delay in the development of A. aurantii instars was observed in the MD plot. This delay increased the period of exposure of the susceptible instars to natural enemies, which resulted in higher predation and parasitism levels in the MD plot. Under laboratory conditions, A. melinus mating behaviour and effects on A. aurantii were not significantly altered in a CRS-pheromone-saturated environment. CONCLUSION: Mating disruption pheromone did not affect the behaviour or level of parasitism by A. melinus or the incidence of other generalist predators. Therefore, A. aurantii pheromone appears to be compatible with augmentative releases and biological control, making its use a good strategy for CRS management. 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。     

Attract-and-kill strategy. Laboratory studies on hatched larvae of Culex pipiens

The attract‐and‐kill strategy is a new pest management technique that presupposes the intelligent combination of an attracting agent (e.g. pheromone) and a killing agent (e.g. insecticide). In the present study, the potential combination of the microencapsulated synthetic oviposition pheromone 6‐acetoxy‐5‐hexadecanolide with an insecticide has been tested. Initially, polyurea microcapsules containing 6‐acetoxy‐5‐hexadecanolide, the synthetic mixture of diastereomers of the oviposition pheromone of the mosquito species Culex quinquefasciatus Say (Diptera: Culicidae), were studied. Laboratory bioassays were performed to confirm the bioactivity of the microencapsulated pheromone on the oviposition activity of Culex pipiens L. biotype molestus Førskal (Diptera: Culicidae) with the aim of determining the optimum dose for oviposition response. Its effect was dose dependent, revealing an optimum dose of 300 mg of dried microcapsules. Attractancy over time was also studied. The microencapsulated pheromone was found to be sufficiently attractive to gravid female mosquitoes for a period of 40 days. Finally, the combination of the synthetic pheromone with the control agent temephos showed both an acceptable oviposition activity and sufficient larvicidal effect. Copyright © 2007 Society of Chemical Industry     

Comparison of pheromone lures used in mass trapping to control the tomato leafminer Tuta absoluta (Meyrick, 1917) in industrial tomato crops in Kairouan (Tunisia)

An experimental trial of integrated pest management against Tuta absoluta (Meyrick) based on mass trapping with a density of 32 traps per hectare was conducted in a 5 ha open‐field tomato crop. During this trial, the efficiency of three brands of sex pheromone dispenser commercialized in Tunisia was tested. The ‘superdosed’ pheromone lure type TUA‐Optima^® (Russell IPM, Deeside, Flintshire, CH5 2LA, United Kingdom) loaded with 0.8 mg of synthetic pheromone was more attractive to males of T. absoluta, and these lures should be used with high populations. Standard lures Pherodis^® and TUA‐500^® containing 0.5 mg of pheromone were less attractive, and can be used in open‐field tomato crops with lower populations of T. absoluta. An assessment of the susceptibility of crop borders to T. absoluta, based on data collected from traps, revealed that levels of adult T. absoluta were similar between borders with either tomato or cereal crops. Particular attention should thus be paid to crop borders even when not adjacent to other tomato crops.     

黄野螟性信息素分泌腺形态及超微结构

为深入了解黄野螟Heortia vitessoides性信息素生物合成及释放机制,采用光学显微镜、扫描电镜和透射电镜对黄野螟雌成虫性信息素分泌腺形态和超微结构进行观察。结果表明,黄野螟雌成虫性信息素分泌腺为一个完整的环状上皮结构,位于腹部末端第8腹节和第9腹节之间的节间膜上。黄野螟雌成虫性信息素分泌腺表面分布着3类8种感器,即I～IV型毛形感器、I和II型刺形感器及I和II型锥形感器。分泌腺细胞单层密集排列在角质层内表面,细胞呈柱状或圆形,表皮层分为上表皮和内表皮,细胞中还有发达的肌肉层、脂滴以及线粒体等结构组织。     

The Potential of Semiochemicals for Control of Phorodon humuli (Homoptera: Aphididae)

Field experiments employing yellow water-traps with vials releasing methyl salicylate, butyl isothiocyanate, 4-pentenyl isothiocyanate and diethyltoluamide were conducted during the spring migration of Phorodon humuli (Schrank), with the aim of identifying substances which might be used in the field to deter landing on hop plants. Methyl salicylate and the two isothiocyanates reduced trap catches of P. humuli. During the spring of 1994 a slow-release formulation of methyl salicylate and a β-acid-rich hop resin sprayed on to hop plants did not reduce aphid infestations significantly. In autumn cis,cis-nepetalactol, the main component of P. ‘humuli’s sex pheromone, prepared by various synthetic routes, increased trap catches of males and gynoparae equally. Catches of males in pheromone traps situated in a hop garden decreased with increasing trap height. Catches of males in traps charged with increasing doses of the cis,cis-nepetalactol peaked at 1 mg and then plateaued, whereas catches of gynoparae peaked similarly at 1 mg and then decreased. The effects of kairomones from an extract of the primary host, sex pheromone and a visual cue from yellow compared with clear water-traps were additive. The prospects for developing a semiochemicals-based control strategy against P. humuli, using some or all of the above elements, are discussed.     

Application technology of the sex pheromone of the tea geometrid Ectropis grisescens (Lepidoptera: Geometridae)

The sex pheromone of Ectropis grisescens, one of the primary defoliator insects of tea plantations, has been identified, but its trapping parameters have not been optimized for field application. In this study, we investigated the effects of pheromone dose, trap height and trap type on the effectiveness of trapping E. grisescens in the field. Our results show that the optimal pheromone dose is 800 μg. The bucket-funnel trap hung 40 cm below the tea canopy had the highest trapping efficiency. This study establishes optimized parameters for the pheromone trapping of E. grisescens in tea plantations.     

Experience with pheromone trapping and disruption of moths

Maxima in the population of the summerfruit tortrix moth, Adoxophyes orana, have been detected in orchards in the Netherlands using traps containing its pheromones. Attempts to disrupt the pheromone communication of A. orana in orchards using geometrical isomers of the pheromone have given variable results. Factors, in particular temperature, affecting pheromone communication in A. orana are discussed.