Field evaluation of purified Z-9, E-11-tetradecadienyl acetate as an attractant for males ofSpodoptera littoralis (Boisd.) (Lepidoptera,Noctuidae)

The efficiency of 100% purified Z-9, E-11-tetradecadienyl acetate, the major sex attractant for males ofS. littoralis, was evaluated in a field test. A trap (17-cm diameter) baited with 2 mg of the purified attractant dispensed in polyethene vials, was significantly less efficient in attractiveness than a trap baited with one virgin female. The importance of a synergistic component for improving the efficiency of theS. littoralis sex pheromone is discussed.     

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.     

Captures ofEarias insulana males in water traps and dry funnel traps baited with synthetic pheromone or virgin females

(E, E)-10,12-hexadecadienal (HDD) effectively attracted males ofEarias insulana (Boisduval) when released from polyethylene vials but not from rubber dispensers. Traps baited with 3 mg HDD/trap were as effective in luring males as traps baited with four virgin females. Funnel traps baited with either HDD or virgin females captured significantly more males than water traps baited with the same lures.     

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.     

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.     

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.     

二化螟性诱剂和诱盆设置技术的研究

通过对二化螟性诱剂水盆诱捕器及其设置高度比较研究,结果表明：诱捕器的口径大小以２４ｃｍ为佳,绿色水盆的诱蛾量比其他颜色的要大;在越冬代诱捕中,诱盆的高度在２０ｃｍ左右效果较好;性诱剂离水面的高度对二化螟雄蛾的诱捕有一定影响,其高度在０.５～１.０ｃｍ的诱蛾量最高。     

性信息素笼罩诱捕器和水盆诱捕器诱捕棉铃虫雄蛾效果比较

1997年在南疆棉区研究了性信息素笼罩诱捕器和水盆诱捕器对棉铃虫的诱捕效率。试验结果表明 ,伽师县2乡和铁日木乡两地笼罩诱捕器的诱蛾量分别是水盆诱捕器的18.6倍和11.9倍。经统计分析 ,诱蛾量随季节推移有下降趋势。根据笼罩诱蛾效果及其相对稳定性 ,作者希望在我国尽快用笼罩诱捕器取代水盆诱捕器进行棉铃虫成虫的标准化监测。     

Mating,longevity, fertility and fecundity of the cotton leaf-worm,Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae)

The mechanisms adopted to ensure mating success, fertility and fecundity ofS. littoralis were studied. The male moths usually mate only once a night but they mate repeatedly during most of their life span, and practically all their spermatophores are equally efficient for inseminating a female. Although females are also multiple maters, one spermatophore is sufficient for a female to lay fertile eggs throughout her life with no reduction in potential fecundity. While a male may mate 5.3 times, on the average, a female may mate only 2.3 times. As a pronounced decrease in pheromone release occurs after mating, a repeat mating by a female will occur only after most neighboring competitive virgin females have been inseminated. A male may mate therefore with 5.3 different females, all of which will be thoroughly inseminated. The female moth is ready to mate just after emergence and at any time throughout her life. If mating is delayed the preoviposition period is greatly prolonged and eggs are saved to be laid later, after mating, as fertile eggs. Delay in egg laying due to delayed insemination does not result in reduced fecundity as it is compensated for by prolonged longevity. Even if mating is greatly delayed and occurs after egg laying has already begun, the potential reduction in reproduction is not very great, due to the low daily egg-laying rate and the increased longevity of unmated females. It appears unreasonable to expect any tendency toward reduction of egg production with a decrease in the ratio of adult males in a population; for this purpose the control of males must be essentially complete. Therefore, a behavioral control program by mass trapping ofS. littoralis males is unlikely to be economically feasible.     

食诱剂与不同诱捕器结合使用对棉铃虫成虫诱捕效果的影响

为明确不同类型诱捕器对棉铃虫块状食诱剂田间诱捕效果的影响,2018年7月-9月在河北省廊坊市广阳区、河南省新乡市新乡县和原阳县的棉花、大豆、玉米、花生田,利用蛾类诱捕器和三角形诱捕器比较了块状食诱剂对棉铃虫的诱捕效果。结果表明,食诱剂分别与2种诱捕器结合,在4种作物田对棉铃虫成虫均具有明显的诱捕作用;蛾类诱捕器诱集到的棉铃虫成虫数量是三角形诱捕器的1.2~6.5倍。因此,蛾类诱捕器与棉铃虫块状食诱剂结合使用可以更有效诱捕田间棉铃虫成虫。     

Effects of moon phases and of various trap colors on the capture ofprays citri males in sticky traps

Field experiments with sticky traps baited with live females showed that significantly latger numbers ofP. citri males were captured during full-moon than during new- or old-moon phases. Significantly smaller numbers ofPrays citri males were captured in white sticky traps than in black, green, red, yellow or blue ones, placed during day and night in citrus groves in various areas of the country; no significant differences were noted between any of the colored traps.     

Field evaluation of the synthetic female sex pheromone of the citrus flower moth,Prays Citri (mill.) (Lepidoptera: Yponomeutidae), and related compounds

The synthetic female sex pheromone ofPrays citri, (Z)-7-tetradecenal, proved to be highly attractive to male moths in the field when released from a variety of dispensers in five different designs of sticky trap. When the pheromone was released from impregnated polyethylene vials, a wide range of initial loadings from 10 μg to 20 mg was attractive, and loadings of 40 μg and above were more attractive than a virgin female moth. Initial loadings of 0.5 mg and 1.0 mg remained attractive for at least five months in the field. Release rates of pheromone from the polyethylene vials under constant laboratory conditions were measured for two different initial loadings. Other isomers of the pheromone and a pheromone ‘mimic’, (Z)-5-dodecenyl formate, were unattractive to male moths and did not affect the attractiveness of the synthetic pheromone or of a virgin female moth.     

Sex pheromone traps for detecting and monitoring the raisin moth,cadra figulilella,in date palm plantations

Field tests were carried out to determine whether pheromone traps, baited with (Z,E)-9,12-tetradecadienyl acetate (Z9,E12-14:Ac) impregnated in rubber septa (Maavit, Israel), could provide a reliable tool for monitoring the raisin moth,Cadra figulilella (Gregson), in date palm plantations. No significant differences were detected between captures of males in traps baited with 1 or 10 mg pheromone/dispenser. However, traps baited with 1 mg pheromone captured significantly more males than those baited with 0.1 mg pheromone/dispenser. No differences were found between captures of males in traps hung at a height of 8 m (near the bunches) or 2–3 m (on palm trunks). Two peaks of male capture were detected, one in May-June and the other during September-October (ripening period). Results indicate a positive relationship between captures in traps and infestation levels by larvae. Pheromone traps baited with 1 mg Z9,E12–14:Ac impregnated in rubber septa and hung on palm trunks (at a height of 2–3 m), were very useful for monitoringC. figulilella populations and for determining the accurate timing of insecticide applications.     

Influence of killing agents and water on the capture of six coleoptera species in probe traps

The introduction of propylene glycol, DDVP and water inside perforated probe traps was evaluated on the basis of their effectiveness in trapping adults of six species of Coleoptera infesting stored cereals. Adults ofSitophilus oryzae, Tribolium castaneum, Cryptolestes ferrugineus, Tenebroides mauritanicus, Rhyzopertha dominica andOryzaephilus surinamen-sis were placed in plastic cylindrical bins each containing 14 kg of wheat. One probe trap was then introduced into each container and the adults trapped were counted 72 h later. Experiments were conducted at two population densities, of 30 adults (approx. one insect per 0.5 kg of wheat) and 90 adults (approx. three adults per 0.5 kg of wheat) of each species per container. The highest percentage of adults trapped was observed forC. ferrugineus andT. castaneum, and the lowest forR. dominica andS. oryzae. No significant differences in number of adults captured (% of the total number of adults) was noted between the two population density levels. At the lower density, the presence of killing agents in the traps did not increase the captures significantly; on the other hand, at the higher density, the killing agents helped to increase significantly the catches of 5.oryzae, T. castaneum, T. mauritanicus andO. surinamensis, as compared with the catches in the control traps. No significant differences were noted forC. ferrugineus andR. dominica.     

Seasonality of the common cutworm Spodoptera litura in a soybean ecosystem

Seasonal occurrence of the common cutworm Spodoptera litura (Fab.) (Lepidoptera: Noctuidae) moths captured in synthetic sex pheromone traps and associated field population of eggs and larvae in soybean were examined in India from 2009 to 2011. Male moths of S. litura first appeared in late July or early August and continued through October. Peak male trap catches occurred during the second fortnight of September, which was within soybean reproductive stages. Similarly, the first appearance of S. litura egg masses and larval populations were observed after the first appearance of male moths in early to mid-August, and were present in the growing season up to late September to mid-October. The peak appearance of egg masses and larval populations always corresponded with the peak activity of male moths recorded during mid-September in all years. Correlation studies showed that weekly mean trap catches were linearly and positively correlated with egg masses and larval populations during the entire growing season of soybean. Seasonal means of male moth catches in pheromone traps during the 2010 and 2011 seasons were significantly lower than the catches during the 2009 season. However, seasonal means of the egg masses and larval populations were not significantly different between years. Pheromone traps may be useful indicators of the onset of numbers of S. litura eggs and larvae in soybean fields.     

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.     

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     

A preliminary comparison of Magnum 116 bodygrip traps with a live capture trap design during the control of grey squirrels (Sciurus carolinensis)

The grey squirrel is an invasive pest species in the United Kingdom and populations are controlled to protect timber crops and native fauna. Although animals are culled using a variety of methods, there are few data available on the relative efficiency of different trap designs, and in particular spring traps. We compared grey squirrel captures in Magnum 116 spring-traps set within Fineren boxes against captures in a single entry live capture trap design. Trapping was conducted in mature mixed woodland in North Wales. No significant difference in the frequency of grey squirrel captures or body mass of trapped individuals between trap designs was observed. Despite the Fineren box design limiting access by non-target species, by-catch was recorded. We make recommendations for future research to minimise this and also compare our results for Magnum 116 traps with data available on captures in Fenn IV spring traps. The findings have broad relevance to the control of grey squirrels across their wider international invasive range.     

The distribution of olive fruit fly captures with McPhail traps within an olive orchard

The spatial distribution of olive fruit flyBactrocera (Dacus) oleae (Gmelin) (Diptera: Tephritidae) field captures with McPhail traps within an experimental orchard was evaluated. Contour maps were constructed to examine the patterns in the 3-year trapping data. Captures varied widely inside the olive orchard, with traps suspended on wild olive trees exhibiting the poorest performance. Favorable microclimate, created by a standing water pool, appeared to be responsible for increased trap captures during the hot summer months. The positive role of the olive tree fruit load is also discussed. http://www.phytoparasitica.org posting Feb. 2, 2003.     

Estimation of fly population density of Bactrocera oleae in olive groves of Crete

Population density of adults of Bactrocera oleae (Gmelin) (Diptera: Tephritidae) was obtained from olive trees during a two-year study by means of two different methods, namely, knock down by an insecticide applied as a fog (‘sondage’) and trap captures (of yellow sticky panels and McPhail traps baited with ammonium). First it was concluded that yellow sticky panel traps give a poor representation of the olive fruit fly population density of the olive grove. Yellow panel trap captures were significantly lower than McPhail’s (September) and than the actual population of B. oleae as recorded in olive tree canopy (August of 2008). When only McPhail captures were compared to the olive fruit fly population in the tree canopy, B. oleae captures in McPhail traps represented only a small percentage of the population that was recorded in the olive tree canopy (July and August of 2009). It was estimated that traps captured only 0.5% of the flies present within a radius of 20 m in the studied field (which consists of approximately 25 trees). However, during autumn (September), low trap captures of B. oleae can occur even when the fly population in the field is near zero.