Effects of mating factors on reproduction and sex-ratio of the predacious miteamblyseius zaheri yous. & el-bor. (acari, phytoseiidae)

Three factors were examined to determine their effect on the reproduction and sex-ratio in the predacious miteAmblyseius zaheri Yousef & El-Borolossy in the laboratory. The factors studied included multiple matings, disturbed mating and age of mating females. Fecundity of females mated more than once was 3 times higher than in females mated only once. Artificial curtailment of copulation to 120, 60 and SO min resulted in reduction of fecundity and oviposition period. The Age of mated females has an influence also on fecundity, old females produce fewer eggs compared with young females under constant condition of abundant prey. All 3 factors studied have no influence on the sex-ratio of the progeny.     

Effects of mating factors on reproduction and sex-ratio of the predacious miteamblyseius zaheri yous. & el-bor. (acari, phytoseiidae)

Three factors were examined to determine their effect on the reproduction and sex-ratio in the predacious miteAmblyseius zaheri Yousef & El-Borolossy in the laboratory. The factors studied included multiple matings, disturbed mating and age of mating females. Fecundity of females mated more than once was 3 times higher than in females mated only once. Artificial curtailment of copulation to 120, 60 and SO min resulted in reduction of fecundity and oviposition period. The Age of mated females has an influence also on fecundity, old females produce fewer eggs compared with young females under constant condition of abundant prey. All 3 factors studied have no influence on the sex-ratio of the progeny.     

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     

猎物和湿度对三种植绥螨生育的影响

本文报道了从国外引入的西方盲走螨(Metaseiulus occidentalis Nesbitt)、智利小植绥螨(Phytoseiulus Persimilis Athias-Henriot)和国内新近发现的拟长毛钝绥螨(Amblyseius Pseudolongispinosus Xia Laing et Ke)、捕食山楂叶螨(Tetranychus viennensis Zacher)和二点叶螨(T.urticae Koch)的生育情况及其对相对温度的反应。西方盲走螨捕食山楂叶螨与捕食二点叶螨相比,世代发育历期延长,产卵量减少,性比也有所下降。拟长毛钝绥螨捕食两种叶螨,在发育历期和雌成螨产卿量方面差别不显著,但捕食山楂叶螨的性比降低。智利小植绥螨捕食山楂叶螨,对其生育影响最明显,表现雌成螨寿命显著缩短,产卵量和性比下降。在相对湿度29.5～92.5%范围内饲养三种植绥螨,在卵的孵化,幼螨、若螨的成活和成螨产卵方面均有明显的差异。试验表明,西方盲走螨是耐干的种类,拟长毛钝绥螨和智利小植绥螨是喜温的种类,特别是拟长毛钝绥螨对湿度更为敏感。     

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.     

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.     

褐飞虱短翅型雌虫延迟交配对其繁殖的影响

延迟交配往往影响昆虫的繁殖和寿命。本文研究了褐飞虱短翅型雌虫延迟交配对其寿命、产卵量及累计产卵率的影响。结果表明雌虫寿命在不同日龄交配雌虫之间存在明显差异。羽化后2、4、6、81、0 d交配的雌虫,随着交配日龄的增加,寿命延长。4日龄后随着交配日龄的增加,雌虫产卵量逐渐降低。其中4日龄交配雌虫的产卵量最高,约337粒;10日龄产卵量最低,约168粒。不同日龄交配雌虫的累计产卵率差异不明显。     

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     

Evaluation of lufenuron as a chemosterilant against fruit flies of the genus Anastrepha (Diptera: Tephritidae)

BACKGROUND: Chemosterilisation with lufenuron bait stations is a recently developed technique that is being implemented for Ceratitis capitata Wiedemann control. The aim of this work was to evaluate the chemosterilising effect of lufenuron against four economically important Latin American fruit flies species: Anastrepha ludens (Loew.), A. obliqua Macquart, A. serpentina Wiedemann and A. striata Schiner (Diptera: Tephritidae) in order to design a similar strategy for their control. RESULTS: Sexually mature adults were treated by ingestion with concentrations ranging from 0.1 to 30.0 mg g^?1 of lufenuron in the diet. In addition, conspecific crosses with only one of the sexes being treated (30.0 mg g^?1) were performed in order to appraise the contribution of each sex to the sterilising effect. In all cases, fecundity was not affected by the treatments, as opposed to fertility where all Anastrepha species studied were significantly affected, although to different extents. The conspecific crosses showed that treated males of A. ludens, A. obliqua and A. serpentina were not able to transmit the sterility to their respective untreated females. Only in the case of A. striata did crossing treated males with untreated females significantly reduced egg hatch. CONCLUSION: Although further investigations are required, the present results demonstrate that the use of lufenuron for controlling A. striata could be potentially viable. Copyright © 2010 Society of Chemical Industry     

Diethylstilbestrol as a reproduction inhibitor in the Levante vole

Diethylstilbestrol (DES) at 0.019–0.025 mg/g body weight, fed with grain baits to Levante voles (Microtus guentheri [D. & A.]) of different age, sex and physiological condition, suppressed gestation for the first 10 days after mating. These doses, which are consumed voluntarily, also caused sterility in daughters of females which received DES at the end of pregnancy, and sterility or a significant delay (2–3 months) in sexual maturity of females which received it in their mother’s milk during the first days of life. DES had no significant effect on adult nonpregnant females or on males of any age, even if administered 3 days before mating.     

梨小食心虫雄蛾的多次交配对雌蛾生殖力的影响

为明确梨小食心虫雄蛾的交配能力等生物学特性, 正确评价梨小食心虫性信息素诱杀雄蛾的田间应用效果, 本研究借助监控设备观察了梨小食心虫雄蛾与雌蛾的交配时间段、交配持续时间、雄蛾交配次数、雄蛾首次交配及末次交配日龄, 研究了雄蛾日龄对交配率的影响, 雄蛾交配次数对雌蛾产卵量及卵孵化率的影响。结果表明, 梨小食心虫雄蛾能与多头雌蛾交配, 且从1日龄至19日龄期间均能与雌蛾交配。随着雄蛾日龄的增加, 其与雌蛾交配率降低, 雄蛾交配次数的增加对雌蛾产卵量及卵孵化率没有显著影响。因此田间使用性信息素诱杀一定数量的雄蛾对降低后代种群数量有一定的作用, 但只有在短时间内将雄蛾数量减少到一定范围内才可起到理想效果。     

斜纹夜蛾雌雄配对后成虫活动行为节律及时间分配

为了解斜纹夜蛾Spodoptera litura(Fabricius)配对后雌、雄成虫日活动行为节律,在室内人工气候室中配对饲养斜纹夜蛾,连续6 d观察成虫移动、静息、补充营养、产卵和交配5个行为类型。结果表明,在配对后6 d内,斜纹夜蛾的交配、产卵、移动、补充营养和停息行为所占比例均有明显变化,交配行为主要发生在配对后的前2 d,在配对后第6天成虫除偶尔补充营养外基本处于停息状态;交配行为有2个明显高峰期,即00∶00~01∶00(3.89%)和04∶00~05∶00(3.89%),雌、雄成虫移动行为日节律所占比例在03∶00~06∶00和补充营养行为日节律在03∶00~05∶00差异显著;成虫各行为分配频次最多的是停息行为,远高于其它行为,且各行为所占比例差异极显著,但雌、雄成虫之间无显著差异;雌、雄成虫运动行为几乎全部发生在暗期,且在不同时间段无显著差异;光、暗期各行为活动发生的比率差异显著;在暗期不同时间段,除雌蛾的移动行为、雄蛾的补充营养行为和交配行为无显著差异外,其它各种行为均差异显著。表明斜纹夜蛾雌、雄配对后移动、静息、补充营养、产卵和交配行为受成虫日龄影响较大,也受性别影响,表现出明显的日节律性。     

甜菜夜蛾卵和成虫携带核型多角体病毒对种群数量的影响

在室内分别测定了甜菜夜蛾的卵、雌蛾和雄蛾分别携带甜菜夜蛾核型多角体病毒(SeNPV)对其卵孵化率、幼虫存活率及单雌产卵量的影响。结果表明:甜菜夜蛾卵块携带SeNPV后,卵孵化率和幼虫存活率均显著下降。雌、雄蛾分别携带病毒再交尾后,对单雌产卵量、卵孵化率和幼虫的存活率也有显著影响,并且不同带毒量处理间存在显著差异,表现为带毒量越高,单雌产卵量越少、卵孵化率和幼虫存活率越低。同等带毒处理条件下,卵、雌蛾和雄蛾带毒3种处理方式对甜菜夜蛾种群数量的影响没有显著差异。说明SeNPV能通过甜菜夜蛾的卵、雌蛾和雄蛾3种虫态进行垂直传播,可以明显抑制甜菜夜蛾种群数量的增长,为昆虫性诱剂和病毒集成技术在田间的应用提供了理论依据。     

Post‐spray effects of an aerial application of fenitrothion on the pine beauty moth,Panolis flammea (Denis & Schiffermüller)

Abstract

Panolis flammea that had survived an aerial spraying programme of fenitrothion were compared in a series of laboratory experiments with moths that had not been within the sprayed area, to assess the effects of sub‐lethal spray application on various life history parameters. Emergence success was not significantly different between the two treatments and the sex ratio in both cases approximated 1:1. The bionomics of moths surviving in the sprayed plots were different in several respects from those taken from unsprayed plots. The former emerged from pupae later, had lower levels of fecundity and a longer pre‐oviposition period. Females from sprayed plots were also heavierthan males and their weight was positively correlated with fecundity, whereas neither of those traits were shown by unsprayed moths. A number of other bionomic traits were not significantly different in sprayed or unsprayed groups. Analysis of the population growth rates of P. flammea from areas of the forest where control was either ineffective or effective, revealed no significant differences. The implications of these results for the population dynamics of P. flammea are discussed.     

虱螨脲对小菜蛾成虫繁殖力及子代种群发展的影响

为探究虱螨脲对小菜蛾Plutella xylostella成虫的亚致死作用,通过残留药膜法或饲喂法使用50 mg/L虱螨脲对小菜蛾成虫进行处理,分别测定小菜蛾成虫繁殖力、寿命和卵孵化率,通过建立小菜蛾成虫子代生命表确定虱螨脲处理成虫对其后代的影响。结果表明,残留药膜法处理后,小菜蛾成虫单雌产卵量和卵孵化率分别比对照显著降低39.09粒和19.38个百分点;饲喂法处理后,小菜蛾成虫单雌产卵量、雌成虫寿命和卵孵化率分别比对照减少13.42粒、1.56 d和72.03个百分点,卵孵化率与对照差异显著。虱螨脲处理后,小菜蛾成虫子代1龄幼虫存活率、雌成虫寿命、F_1代单雌产卵量和F_1代卵孵化率分别为74.29%、5.90 d、146.65粒和84.43%,均显著低于对照,种群趋势指数降低,表明对子代种群发展有一定的干扰作用。此外,虱螨脲处理小菜蛾雌、雄虫对其产卵量无影响,但处理雌虫显著降低卵孵化率,处理雄虫对卵孵化率无明显影响,说明虱螨脲作用于小菜蛾成虫,仅对卵子形成及受精卵的胚胎发育过程产生影响,而对精子的生成及转移无影响。表明虱螨脲可通过成虫取食或接触而控制小菜蛾种群发展。     

Comparative life history characteristics of the mite predator Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae) on mite and pollen diets

The food diversification strategy that can offer suitable nutrients as a diet for the natural enemies may possibly help to decrease pest populations by boosting the efficiency of predators. Therefore, my objective was to evaluate the effects of plant and animal diets on biological parameters of the phytoseiid mite Neoseiulus cucumeris (Oudemans). This predator that is a natural enemy of mites was reared on plant pollens (maize (Zea mays L.), sweet pepper (Capsicum annuum L.), mungbean (Vigna radiata L.), cucumber (Cucumis sativus L.), tomato (Lycopersicon esculentum Mill.), and rose (Rosa multiflora Thunb.), offered alone, and in combination with the prey mite Tyrophagus putrescentiae (Schrank). Results showed that N. cucumeris fed, developed and reproduced better when it was provided with plant and animal diets together, compared to pollens offered alone. The predator showed the most efficient capability for completion of life parameters (development, survival, fecundity, oviposition, longevity and instantaneous rate of increase) with maize and mungbean ingested pollens in combination with T. putrescentiae. The least competency was observed on cucumber and rose pollens used separately. The lowest developmental time of the predator from neonate larva to adult emergence, the highest immature survivorship, higher fecundity, long oviposition period, and the highest adult female's life span were observed when offered maize pollens along with T. putrescentiae compared to other treatments. Accordingly, the instantaneous rate of population increase (r_i) day^?1 was surpassed by N. cucumeris for the combination of pollen and T. putrescentiae diets than pollens utilized alone. It is determined that N. cucumeris can reproduce and develop more successfully on a food complex consisting of pollen and animal diets than any single diet. These findings reveal that pollen can be used by N. cucumeris as a suitable alternative food in periods when prey in the field is sparse or absent. Moreover, such propensity of predators to feed on food from plant origin increases their survival during periods when prey is locally scarce, but natural enemies might occur at the expense of an ability to utilize food as efficiently as specialized predators to boost the management strategies of pest species in field's ecosystem.     

Reproduction and Development ofAphelenchoides Besseyi

The mode of reproduction of the Indian population ofAphelenchoides besseyi was studied under different temperatures and on different fungal species used for culturing the nematode. Although parthenogenetic reproduction in this species was recorded on all the fungi tested, the influence of the different fungal species on development and population buildup varied. There was a significant increase in nematode fecundity when one or two males were placed along with single females in the medium, as compared with when no male was introduced. Increasing the number of males further to eight depressed fecundity as compared with the treatment with two males.     

Mating and dispersal behaviour of Scirpophaga incertulas and Chilo suppressalis (Lepidoptera; Pyralidae) in relation to resistance management for rice transformed with Bacillus thuringiensis toxin genes

Information on the mating and dispersal behaviour of the rice stem borers Scirpophaga incertulas and Chilo suppressalis is necessary for the design of resistance management strategies for rice varieties genetically engineered with toxin genes from Bacillus thuringiensis (Bt). We investigated whether S. incertulas and C. suppressalis move from the site of adult eclosion before mating to determine the likelihood that random mating will occur between adults eclosing in fields of Bt rice and refuge fields of non-Bt rice. Observations were made under laboratory, screenhouse and field conditions. Almost all S. incertulas males and females flew out of sight after cuticle expansion and hardening, as did most C. suppressalis. Approximately 15% of C. suppressalis females called and mated within 3?m of the site of eclosion, and approximately 5% of C. suppressalis males mated within 5?m of the site of eclosion. These results suggest that random mating is likely to occur between S. incertulas eclosing in Bt rice fields and nearby refuge fields. Although a small proportion of C. suppressalis did not move far before mating, random mating of moths from Bt and nearby refuge fields is also likely to occur in this species if Bt-resistant moths are rare.     

宁夏回族自治区中宁县枸杞红瘿蚊生物学特性及发生规律

为绿色安全防控枸杞红瘿蚊Jaapiella sp.,于2016—2018年自宁夏回族自治区中宁县新堡镇宋营村枸杞种植基地枸杞上采集枸杞红瘿蚊,对其各虫态的形态特征、生活习性和成虫寿命等生物学特性进行室内观察,并对其年生活史及年发生规律进行田间调查。结果表明:枸杞红瘿蚊成虫羽化高度集中,羽化后的雌成虫不需要补充营养,便可立即求偶、交尾和产卵,孵化后幼虫取食子房,致使花蕾畸形膨大形成虫瘿,幼虫老熟后脱离虫瘿并弹跳入土结茧化蛹。成虫寿命极短,已交尾的雌、雄成虫平均寿命分别为41.8 h和38.3 h;未交尾的雌、雄成虫平均寿命分别为28.5 h和16.6 h。枸杞红瘿蚊每年发生6代,以老熟幼虫在地表土层中越冬,每年4月中旬至9月下旬为其为害期,其中第1代、第2代和第6代幼虫为害严重。枸杞红瘿蚊成虫发生高峰期有2个,分别为4—6月和9月。从4月枸杞红瘿蚊越冬代成虫陆续羽化开始,其成虫数量不断增长,4月和5月成虫数量分别为121头和167头,6月达到第1个高峰,为282头,随着枸杞秋枝萌发,9月枸杞红瘿蚊成虫数量又明显增多,达到第2个高峰,为117头。2017年4—10月从田间共收集788头成虫,雌成虫数量为420头,略高于雄成虫数量,雌雄比介于1.11～1.19之间。