The Use of Sex Pheromones in the Control of Spodoptera littoralis Boisd.1)

An even network of pheromone traps baited with virgin females of Spodoptera littoralis Boisd. was established in Cyprus. By relating trap catches with meteorology it was shown that no major immigration of S. littoralis to Cyprus from surrounding land-masses had occurred. Direct control of S. littoralis by the synthetic pheromones recently synthesized or the sterile male technique may therefore be possible in such an area of ecological isolation.     

The use of traps baited with live females or synthetic pheromone as a tool for improving control programs of the cotton leaf-worm,Spodoptera littoralis (Boisd.), in cotton fields in israel

The aim of this investigation was to clarify whether pheromone traps could provide a reliable tool for early detection of aS. littoralis adult population and for indicating infestation by its larvae in the field. The aggregated pattern of distribution of adults is indicated by the fit of data to Taylor’s Power Law or to the negative binomial distribution. However, the relatively high k values obtained indicate thatS. littoralis adults are only slightly aggregated and sometimes almost randomly distributed. Trap position in the field and number of traps per area unit affected size of catches in both female-baited and synthetic-pheromone-baited traps. No relationship between size of catches and temperature, wind velocity or moon phase was detected. Variations in size of catches among traps was not affected much by the baited females. Pheromone traps proved to be a reliable tool for estimating fluctuations in population density and for indicating adult peaks. However, no correlation between male catches and infestation by larvae in the experimental plots was found. Pheromone traps may serve only as a warning device indicating the possibility of potential attack due to an increase in adult population level. Mercury vapor light traps were inferior to pheromone traps in detecting changes inS. littoralis population densities. Synthetic pheromone (“Litlure”) was somewhat less efficient in attracting males than virgin females; however, it is suitable for detecting fluctuations in theS. littoralis adult population.     

Night observations on the cotton leafworm,Spodoptera littoralis: Reliability of pheromone traps for population assessment and efficacy of widely separated pheromone dispensers for mating disruption

Night observations on the cotton leafworm,Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae), were conducted in pheromone-treated and untreated plots in which males, females, mating pairs on plants, and males caught in traps were collected. Results indicated that emergence of a new population was rapid (8-9 days) and that the number of virgin females and of mating pairs on plants reached a peak 5–6 days prior to that of males captured in pheromone traps. Males responded to pheromone traps most actively when the actual virgin female popution had already declined considerably. Dispensers adsorbed with(Z,E)-9,11-tetradecadienyl acetate and located 25 m apart, effectively reduced male captures in traps. However, the number of native mating pairs observed in the treated field during the night was not reduced. Few releasers at wide spacing, even with high amounts of the major pheromonal component, were ineffective in causing mating disruption ofSpodoptera littoralis.     

Efficiency of the synthetic sex attractant and the effect of trap size on captures ofSpodoptera littoralis males in water traps and in dry funnel traps

The efficiency of the synthetic sex attractant ofS. littoralis and the effect of trap size on male captures in water traps and in newly designed dry traps were investigated. The synthetic attractant was less efficient in attractiveness than virgin females in both small (17 cm) and large (60 cm) traps. Trap size did not affect male captures in traps baited with either virgin females or synthetic pheromone. The dry trap tested was as efficient as the water trap, easier to handle, and highly suitable for monitoring or for mass trapping ofS. littoralis.     

Catching Ips duplicatus (Sahlberg) (Coleoptera: Scolytidae) with pheromone‐baited traps: optimal trap type,colour, height and distance to infestation

BACKGROUND: Field trapping experiments were carried out to evaluate effective trap characteristics for maximising Ips duplicatus (Sahlberg) catches in pheromone‐baited traps in China. RESULTS: Window‐slot and cross‐barrier traps had significantly higher catches than multiple‐funnel traps. The colour of window‐slot traps showed a significant effect on catches, with dark colours (black and red) being more effective than light colours, especially white and yellow. Window‐slot traps at a 1.5–2.0 m level caught more beetles than those at either ground level (0–0.5 m) or at 3.5–4.0 m. Ips duplicatus can be attracted to pheromone‐baited traps over a distance of > 100 m from the forest edge in an open grassy field. There was a strong diurnal pattern of flight activity, with catches on window‐slot traps occurring during the daytime with one broad peak at mid‐ to late afternoon. The seasonal flight activity of I. duplicatus as monitored by pheromone‐baited window‐slot traps during 2007–2008 indicated that three major flight peaks occurred in early June, late June–early July and late July respectively, suggesting the existence of a potential second generation. CONCLUSION: The optimal trap characteristics will improve the performance of pheromone‐baited traps as a critical monitoring or mass‐trapping tool to combat outbreaks of this pest species. Copyright © 2009 Society of Chemical Industry     

Trapping Cryptophlebia illepida and C. ombrodelta (Lepidoptera: Tortricidae) in macadamia in Hawaii

Abstract

Two species of Cryptophlebia found in Hawaii's macadamia orchards are active in different parts of a tree canopy. C. illepida (Butler) males were mostly caught in traps hung 1·5 m to 9.1 m from the ground; whereas C. ombrodelta (Lower) males were caught from 9.1 m to 15.2 m. A plastic, cylindrical sticky trap caught equal numbers of C. illepida males as Pherocon 1C traps but more than delta traps. A synthetic pheromone blend of 93% (Z)‐8‐dodecenyl acetate, 4% (E)‐8‐dodecenyl acetate, 1% (Z)‐8‐dodecenol, and 2% (2)‐7‐dedecenyl acetate attracted more males than other blends. No significant differences were detected between the two Cryptophlebia species in their response to the four‐component pheromone blend when traps were hung 4.6 m from the ground.     

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.     

Captures of markedspodoptera littoralis (boisd.) male moths in virgin female traps: Effects of wild male population,distance of traps from release point,and wind

Field experiments were conducted to clarify the effective sphere of pheromone traps for capturingS. littoralis males. Most males were recaptured on the night of release and only a few were trapped on the following night. Recapture of males was not affected by the number of wild males present in the field. Percent recapture was negatively correlated with the distance of traps from the release point, decreasing markedly at distances beyond 100 m. Percent recapture was not affected by wind speeds ranging from <1 to 5 knots per hour, but was affected by wind direction.     

(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 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     

茶尺蠖性信息素的田间使用技术及防治效果

为明确茶尺蠖Ectropis obliqua性信息素的田间使用技术,在田间设置茶尺蠖性信息素诱捕器的5、10和20 m挂放密度处理区及其对照区,并对不同处理区和对照区中诱捕器诱集的茶尺蠖成虫和幼虫数量以及同一挂放密度下距性信息素诱捕器不同距离的茶尺蠖幼虫数量进行调查,确定性信息素诱捕器的最佳挂放间距;在此基础上确定性信息素诱捕器对茶尺蠖的田间防治效果,并利用性信息素诱捕器对茶尺蠖成虫的田间动态进行监测。结果表明:在任何一个挂放密度下,处理区诱捕器诱集的茶尺蠖成虫数量均显著高于对照区诱捕器,但在不同挂放密度的小区之间单个诱捕器诱集的成虫数量差异不显著;当茶尺蠖幼虫重度发生(1 361.57头/m~2)时,10 m间隔挂放1套性信息素诱捕器可显著降低茶尺蠖幼虫的发生数量;当茶尺蠖幼虫轻度发生(38.40头/m~2)时,间距为20 m挂放一套性信息素诱捕器时,茶尺蠖的校正防治效果可达88.44%;茶尺蠖性信息素诱捕器在6月上旬、8月上旬、8月下旬至9月初、9月下旬分别有一个明显的诱捕高峰期,与田间茶尺蠖的发生高峰期基本一致。表明茶尺蠖性信息素诱捕器可作为大量诱捕和虫情监测的手段在茶园中应用。     

Optimum timing of insecticide applications against diamondback moth Plutella xylostella in cole crops using threshold catches in sex pheromone traps

Field trials were conducted in cabbage (Brassica oleracea var capitata), cauliflower (B oleracea var botrytis) and knol khol (B oleracea gongylodes) crops at two different locations in Karnataka State (India) to optimize the timing of insecticide applications to control the diamondback moth, Plutella xylostella, using sex pheromone traps. Our results indicate that applications of cartap hydrochloride as insecticide during a 12–24 h period after the pheromone traps had caught on average 8, 12 and 16 males per trap per night in cabbage, cauliflower and knol khol, respectively, were significantly more effective than regular insecticide sprays at 7, 9, 12 or 15 days after transplantation. This was demonstrated by estimation of the mean number of eggs and larvae per plant, the percentage of holes produced, as well as the marketable yield of the three crops at each location. A good correlation between the immature stages, infestation level, the estimated crop yield and the number of moths caught in pheromone traps was also found, indicating the usefulness of pheromone‐based monitoring traps to predict population densities of the pest. © 2001 Society of Chemical Industry     

Efficacy of carbofuran and phorate at different intervals of application for control of rice tungro

Abstract

The relationship between the catch of male Spodoptera litura (F.) moths in sex pheromone‐baited traps and the number of egg‐masses in groundnut crop at the International Crops Research Institute for Semi‐Arid Tropics Centre Patancheru, India was examined during the post‐rainy season of 1983. Significant positive correlations were found between the number of egg‐masses and the total number of male moths caught during the 7 days preceding the egg‐mass count. 75% of the variance in the egg‐mass counts and pheromone trap catches could be accounted for by the regression.     

Improving Control of the Vegetable Armyworm

Abstract

Because of recently acquired resistance of armyworm in Cyprus to prophyllactic spraying of methylparathion, a full investigation into the biology of Spodoptera littoralis was launched. It is not yet clear whether immigration to the Island occurs, but some moths can overwinter in “survival pockets” on the South coast. Pheromone traps and sterilisation are suggested as an alternative method of control. A more rational use of pesticides will cause less damage to natural enemies of the pest and reduce further development of resistance.     

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.     

Studies of the Pink Bollworm,Pectinophora gossypiella,on Sea Island Cotton in Barbados

Abstract

Barbados once grew large amounts of Sea Island cotton but the accidental introduction of pink bollworm (Pectinophora gossypiella) in the 1920s, falling prices and rising costs led to the collapse of the industry. Falling sugar prices subsequently led to a revival of interest in the crop but pink bollworm still presented a problem and warranted investigation.

The synthetic sex pheromone of pink bollworm, gossyplure, was shown to attract far more males than hexalure or virgin females. Sticky traps needed stirring daily and were only able to catch about 50 males a night. Water, with a drop of liquid detergent, proved to be a suitable trapping medium and was cheaper than liquid paraffin although not quite as effective. The best type of trap from materials readily available was one made from a plastic half gallon ice cream container with lid and holes cut around the upper sides. Traps without the attractant caught very few moths. Gossyplure adsorbed onto rubber caps was attractive to pink bollworm males for over 56 days but the half-life appeared to be about 28 days. Best catches were obtained in cotton when the traps were suspended just below the tops of the plants and, within fields, traps at the leeward end caught more than traps elsewhere. Peak catches of males occurred before midnight in a black light trap whereas pheromone traps caught no males before midnight but peaked at 03.00h.

A close season during which no cotton is allowed to grow is a recognised means of reducing pink bollworm carryover between crops. This was practised in Barbados but island-wide pheromone trapping showed that moths were caught throughout the close season. This continuous trapping of moths indicated that pink bollworm must be breeding (short-cycle) in order to survive. Trapping and laboratory studies confirmed the presence of long-cycle pink bollworm which entered diapause towards the end of the cotton season as daylength increased. This diapause terminated with shortening days after the new season's rains commenced. The case for a four month close season is discussed.

Pheromone trap catches were shown to be very closely correlated with boll damage. Catches of 8–9 moths in a night represented a 10% level of boll damage some ten days later and this is the trapping level at which cotton growers are advised to begin insecticidal treatment.

Thorough residue destruction is the key to a good close season and a suitable method was needed for use under Barbadian conditions. The method finally chosen and proved on an estate scale was to cut down the standing cotton with a horizontal-rotary chain slasher, driving across the rows of cotton, the debris was then raked along the rows, stacked and burnt and finally the stumps were ploughed in, again across the rows.

The parasite Perisierola nigrifemur is very common in pink bollworm larvae towards the end of the season but too late to be of economic value. Predation of diapausing larvae by the mite Pyemotes ventricosus is very common at the end of the cotton crop and during the close season. Insecticidal application in Sea Island cotton which usually grows very tall (> 1.75m) and rank is best achieved with hand-held, battery-operated, u.l.v. sprayers. Control of pink bollworm can be obtained with carbaryl S formulations applied through these sprayers with the addition of a little water and molasses. Synthetic pyrethroids in u.l.v. formulations are also expected to provide control.     

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     

Sex ratio and mating status ofSpodoptera Littoralis females collected from light traps in Israel

Spodoptera littoralis moths were collected from two mercury vapor light traps in Israel, sexed, and the females dissected to establish the number of times each had mated. The sex ratio was in favor of males. The higher the percentage of males in the trap, the higher was the corresponding percentage of mated females and number of matings per female. MostS. littoralis females mated more than once. The mating status varied with location and season.     

Non-target beetles (Coleoptera) in Trypodendron pheromone traps in Finland

Non-target beetles were surveyed in Trypodendron pheromone traps in 3 localities in Finland. Two window traps baited with Trypolure, containing lineatin dissolved in ethanol, and one control trap without attractant were used in each locality. A total of 1648 specimens belonging to 223 non-target species were recorded. The species were divided into five ecological groups to be treated separately. Hylurgops palliatus and Hylastes cunicularius were abundant in baited traps, whereas other scolytids as a group did not show clear attraction. Other species living in recently dead trees, including bark- and wood-boring species and associated species (predators, scavengers, fungivores, etc.), were clearly attracted by Trypolure. The most abundant ones were Hylecoetes flabellicornis, Thanasimus formicarius, Rhizophagus dispar, and Rhizophagus nitidulus. Although numerous in the samples, saproxylic species inhabiting more decayed wood and non-saproxylic species did not seem to be attracted. Grouping of species into ecological groups was helpful in the search for attraction patterns among species that usually are scarce in pheromone traps.     

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.