颜色对苹果蠹蛾产卵选择性的影响

苹果蠹蛾Cydia pomonella Linne是为害苹果Malus pumila Mill.、梨Pyrus spp.、桃Amygdalus persica L.等仁果类和核果类果树的重要蛀果害虫之一.为明确寄主颜色在苹果蠹蛾产卵中的作用,本文研究了不同颜色对苹果蠹蛾雌成虫产卵选择性的影响.试验采用彩色硫酸纸模拟寄主...     

Effects of predation on clutch size and egg dispersion in the codling moth Laspeyresia pomonella

ABSTRACT.

• 1 The effects of predation on clutch size and egg dispersion in the codling moth Laspeyresia pomonella (L.) were experimentally studied in an orchard by recording survival of eggs glued onto different substrates.
• 2 Egg mortality due to sucking insects was readily distinguishable from that due to chewing insects.
• 3 In both the field and laboratory, females preferred to deposit eggs singly on the uppersides of leaves.
• 4 Eggs on the uppersides of leaves and on fruit survived significantly better than did those on the undersides of leaves or on twigs.
• 5 Egg losses were highest during the early part of the flight season.
• 6 The smallest (one egg) and largest (nine eggs) clutches, associated with one egg-bearing leaf per twig, both suffered the lowest rates of predation. Factors selecting against oviposition on fruits and production of large clutch sizes are presented and discussed.

     

Genetic architecture in codling moth populations: comparison between microsatellite and insecticide resistance markers

The codling moth, Cydia pomonella, is renowned for developing resistance to insecticides and causing significant economic damage to pome fruits worldwide. In spite of its economic importance, little is known about the patterns of movement of this pest and the effects of insecticide treatment on the population genetic structure. Here, we investigated the genetic structure of the pest in 27 orchards from France, Italy, Armenia and Chile at seven microsatellite loci and two resistance markers [biochemical activity of cytochrome P450 oxidases and proportion of knockdown resistance (kdr) alleles in the sodium channel gene]. According to the microsatellite loci, we detected isolation by distance at the supranational scale but found no evidence of geographical structure among the 24 French orchards, which were mainly structured by the intensity of the insecticide treatments. Similarly, the highest levels of metabolic resistance associated with activity of the cytochrome P450 oxidases were detected in the most treated orchards. The kdr alleles were observed in southern France and Armenia where the pyrethroid insecticides were or have been intensively sprayed. The intensity of the insecticide treatments marginally affected the allelic richness in each orchard, but not the level of inbreeding. These results suggest important and high-distance gene flow among the codling moth populations, which were mainly structured according to the history of insecticide applications. Differences in mutation-migration-drift equilibrium among treated and untreated orchards also suggest that insecticide applications are the main force regulating the local dynamics of codling moth populations.     

Effect of radiation on fecundity and fertility of codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) from South Africa

Codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) is the key pest of pome fruit in South Africa, and it’s control in apple and pear orchards relies on the application of insecticides and pheromone‐mediated mating disruption. Development of resistance to insecticides and placement of restrictions on the use of certain insecticides has made control of codling moth in South Africa increasingly problematic. The use of the sterile insect technique (SIT) as a control tactic for codling moth is under investigation as a potential addition to the current control strategy. We investigated the radiosensitivity of a laboratory strain of codling moth that was established from moths collected from commercial and organic orchards in the Western Cape, South Africa. Fecundity and fertility of this strain following radiation were consistent with values for the codling moth strain in the Canadian rearing facility in British Columbia. For both strains, the female codling moth was considerably more radiosensitive than the male. At a radiation dose of 100 Gy or higher, treated females were 100% sterile. The fertility of the South African strain was higher (86.3%) than for the Canadian strain (71.9%). This difference in fertility between the two strains was maintained when the dose of radiation was 100 Gy. However, the level of fertility was very similar between the two strains for doses ≥150 Gy. Therefore, based upon previously published work and the data from this study, an operational dose of 150 Gy is recommended for future codling moth SIT programmes in South Africa.     

Differential ovicidal and larvicidal resistance to benzoylureas in the codling moth, Cydia pomonella

French populations of the codling moth Cydia pomonella (L.) (Lepidoptera, Tortricidae), a major pest in apple and pear orchards, have developed resistance to different classes of insecticides including the benzoylurea diflubenzuron, a chitin synthesis inhibitor. Ovicidal tests performed on two susceptible strains and one strain selected for its resistance to diflubenzuron revealed the same order of magnitude in resistance ratios to this compound (30-fold) and two other benzoylureas teflubenzuron and flufenoxuron (22- and 11-fold, respectively). Field rates of these three compounds induced a 45–55% decrease in hatching in the resistant strain, compared to over 90% in the susceptible insects. Despite a 52-fold ovicidal resistance ratio to the juvenile hormone analog fenoxycarb, this compound induced a 85% decrease in hatching in the resistant strain. Conversely the newly hatched larvae of the resistant strain exhibited a 45 000-, 33- and 2.1-fold resistance ratio to diflubenzuron, teflubenzuron and flufenoxuron, respectively. The latter value was not significant, and the field rate of flufenoxuron killed over 97% of the resistant larvae while diflubenzuron had no effect. This lack of relationship between ovicidal and larvicidal resistance may be due to different transport properties together with differential enzymatic metabolization. Our results may limit the validity of substitution instars, which approach is frequently used for resistance monitoring. More importantly for resistance management, the resistance of different target instars to each compound has to be considered when establishing control strategies.     

Juvenile hormone catabolism and oviposition in the codling moth, Cydia pomonella, as functions of age, mating status, and hormone treatment.

In vitro catabolism of juvenile hormone (JH) in haemolymph of adult female Cydia pomonella was ascribed mainly to juvenile hormone esterase (JHE) activity. No significant differences were noted between virgin and mated females 0-96 h post-emergence. Changes in JHE activity did not appear dependent upon fluctuations in JH titre; conversely, changes in JHE activity could not explain the changes in JH titres. Maximal JHE activity was recorded at 24 h (331.47 +/- 47.25 pmol/h/microl; 355.93 +/- 36.68 pmol/h/microl, virgin; mated insects, respectively) and preceded the peak in JH titres at 48 h. Topical application of JH II (10 ng-10 microg) or fenoxycarb (50 ng) enhanced JHE activity up to 640 and 56%, respectively. Treatment upon emergence with 10 microg JH II induced enzymic activity for less than 24 h, and when 10 microg JH II or 50 ng fenoxycarb were applied, circulating JH titres returned to control levels within 24 h. Oviposition was highly sensitive to exogenous JH and declined significantly with dosages >100 pg. To allow a degree of oocyte maturation before JH treatment, the hormone was administered at 6, 12, 24, or 48 h post-emergence and/or females were mated. Neither measure "protected" the system; oviposition declined immediately after JH application.     

两种苹果蠹蛾性引诱剂诱捕器诱捕效率比较及地面植被的影响

在甘肃省高台县通过对三角胶粘式和水盆式这2种类型苹果蠹蛾Cydia pomonella(L.)诱捕器的田间比较研究。结果显示,二者在诱捕效率上存在的明显差异。在苹果蠹蛾密度较低的条件下,三角胶粘式诱捕器平均日诱捕量为2.50只,比水盆式诱捕器高出近2.84倍,最早监测到成虫的时间也比水盆式诱捕器提前3~4d,因此,三角胶粘式诱捕器具有更高的监测效率。结果还显示地面植被的遮盖极大地降低诱捕器的诱捕效果,严重时会使诱捕器对密度较低的苹果蠹蛾种群的监测功能丧失。     

Effect of an ecdysteroid agonist, tebufenozide, on the completion of diapause in susceptible and resistant strains of the codling moth, Cydia pomonella

Codling moth Cydia pomonella (L.) (Lepidoptera, Tortricidae) larvae kept under a short photoperiod enter a diapause which can be broken by exposure to 25°C following an extended chilling period. We investigated the effects of the ecdysteroid agonist tebufenozide on the diapause of this species, both on a laboratory strain susceptible to insecticides and two strains selected for resistance to diflubenzuron or deltamethrin. The treatment induced moulting by breaking diapause of the susceptible strain when applied at the end of the growth period, or by reducing the pre-emergence period when applied after chilling. The strains exhibiting resistance in the neonate instar were also resistant to the ecdysteroid agonist applied to diapausing larvae, indicating that mechanisms of resistance remained active during this arrest of development. High doses of tebufenozide were lethal for the most resistant insects, but neither reduced the pupation delay nor produced the larval-pupal moults which occur in the susceptible strain. As diapausing larvae of C. pomonella can be easily collected, the expression of resistance to tebufenozide both in the target instar, i.e. neonates, and during diapause may contribute to early detection of resistance to this insecticide in field populations.     

Influence of juvenile hormone and mating on oogenesis and oviposition in the codling moth,Cydia pomonella

Oogenesis in the codling moth, Cydia pomonella, and the role of juvenile hormones (JHs) were addressed. Rudimentary ovarian structures were recognisable in day 3–4 pupae, when haemolymph JH was still undetectable by coupled gas chromatography‐mass spectrometry in the selected ion mode (GC‐MS/SIM). The presence of developing oocytes was observed by light microscopy on day 8, coincident with very low JH titres (0.74 ± 0.05 ng/ml JH II). Chorionation was only evident upon emergence, following an increase in JH in the pharate adult (0h old: 4.71 ± 0.34 ng/ml JH II). Analysis of haemolymph from virgin and mated females indicated that JH II was predominant, with approximately equal and lower quantities of JHs I and III (3.3‐ to 5.0‐fold less). When pupae or newly emerged adults were treated with JH homologues, no alteration in ovarian protein content was apparent, but the JH mimetic, fenoxycarb, depressed the number of oocytes filling ≥ 50% follicular volume. Chorion deposition was stimulated by JHs I, II, or III (10 μg), but not by fenoxycarb (0.05 μg, 10 μg). Mating provided correct stimuli for enhanced choriogenesis and egg laying, and, since haemolymph JH titres were concomitantly elevated (approximately 2‐fold), it was postulated that the rise in JH elicited both these events. Application of JHs to virgin females, however, could not mimic mating; only increases in choriogenesis were induced: JH‐treatment of virgins (or mated insects) significantly decreased oviposition rates over 24 and 48 h and markedly reduced the life‐time total number of eggs. Arch. Insect Biochem. Physiol. 41:186–200, 1999. © 1999 Wiley‐Liss, Inc.     

Efficacy of entomopathogenic nematodes (Rhabditida: Heterorhabditidae and Steinernematidae) against codling moth,Cydia pomonella (Lepidoptera: Tortricidae) in temperate regions

The biocontrol potential of South African isolates of Heterorhabditis zealandica, Steinernema citrae, S. khoisanae, S. yirgalemense, and Steinernema sp., was evaluated against codling moth, Cydia pomonella. Codling moth was susceptible to all six nematode isolates at a concentration of 50 infective juveniles/insect (78–100% mortality). Low temperatures (10 h at 17°C; 14 h at 12°C) negatively affected larvicidal activity (≤3%) for all isolates. All tested isolates were most effective at higher levels of water activity (a _w=1). The average a _w50-values for all isolates tested was 0.94 (0.93–0.95), except S. khoisanae 0.97 (0.97–0.98). Regarding host-seeking ability, no positive attraction to host cues could be detected amongst isolates, except for H. zealandica. Three of the isolates, H. zealandica, S. khoisanae, and the undescribed Steinernema sp., were selected for field-testing and proven to be effective (mortality >50%). Insect containment methods used during field experimentation was shown to influence larvacidal activity, as different levels of mortality were obtained using various containment methods (wooden planks vs. pear tree logs vs. mesh cages). Pear tree logs were impractical. Predictive equations were subsequently developed, enabling future trials to be conducted using either planks or cages, enabling the prediction of the expected level of control on tree logs. All tested isolates therefore showed a certain degree of biological control potential, however, none of the experiments showed clear efficacy-differences amongst isolates. The study highlighted the importance of environmental factors to ensure the successful application of these nematodes for the control of diapausing codling moth larvae in temperate regions.     

Antennal response of codling moth males, Cydia pomonella L. (Lepidoptera: Tortricidae), to the geometric isomers of codlemone and codlemone acetate

Single sensillum recordings from Cydia pomonella male antennae showed three different types of receptor neurons. The most abundant type was most sensitive to the main pheromone compound (E,E)-8,10-dodecadienol, while its response to the geometric isomers E,Z, Z,E and Z,Z was comparable to a tenfold lower dose of (E,E)-8,10-dodecadienol. This neuron type also responded to the four behaviorally antagonistic isomers of (Δ,Δ)-8,10-dodecadienyl acetate, among which it was most sensitive to the E,E isomer. Cross-adaptation studies showed that these compounds were all detected by the same receptor neuron type. Receptor neurons specifically tuned to (E,Z) or (Z,Z)-8,10-dodecadienol were not found, although these two compounds are behaviorally active. A second type of receptor neuron responded to all isomers of (Δ,Δ)-8,10-dodecadienyl acetate and was most sensitive to the E,E isomer. This neuron type did not respond to any of the isomers of (Δ,Δ)-8,10-dodecadienol. A third receptor neuron type was highly sensitive to the plant compound α-farnesene. The finding that the receptor neuron type tuned to the main pheromone compound responded even to strong behavioral antagonists aids the interpretation of ongoing behavioral studies for the development of the mating disruption technique in codling moth. Accepted: 3 March 2000     

Control of diapausing codling moth,Cydia pomonella (Lepidoptera: Tortricidae) in wooden fruit bins,using entomopathogenic nematodes (Heterorhabditidae and Steinernematidae)

Stacked wooden fruit bins are frequent overwintering sites for overwintering diapausing codling moth larvae. Control strategies against the codling moth (Cydia pomonella) (Lepidoptera: Tortricidae) in South Africa have been hampered by the reinfestation of orchards from nearby stacked infested fruit bins and by the movement of infested bins between orchards. Worldwide, wooden fruit bins are systematically being replaced with plastic bins, however in South Africa this will not be accomplished in the near future. The objective of this study was to evaluate the potential of two recycled commercially available entomopathogenic nematode (EPN) species, Heterorhabditis bacteriophora and Steinernema feltiae, as well as of a local species, Steinernema yirgalemense, to disinfest miniature wooden fruit bins under controlled conditions in the laboratory. After dipping miniature bins loaded with codling moth larvae in a suspension of 25?IJs/mL of each of the three EPN species, under optimum conditions of temperature and humidity, the highest percentage of control was obtained using S. feltiae (75%). The addition of adjuvants significantly increased S. feltiae infectivity to >95%, whereas it did not result in a significant increase in H. bacteriophora or S. yirgalemense infectivity.     

苹果蠹蛾的综合防控和遗传控制研究进展

苹果蠹蛾是仁果类水果的重要检疫害虫,在世界各地造成了巨大的经济损失。目前对其化学防治、化学生态调控、病毒等防治方法研究较多,但仍不能满足防控该害虫的需要,对新型防控技术的需求日益增强。不育昆虫释放技术(SIT)是一种可控制甚至根除靶标害虫的环境友好型防控技术,但传统SIT技术存在一定的局限性,如较难区分性别与筛选雌雄虫、辐射不育昆虫的交配竞争力和适合度降低等问题,这些缺陷随着昆虫遗传修饰技术的发展将得以解决,并将在害虫防控进程中起到积极作用。本文综述了苹果蠹蛾主要防控技术研究现状,介绍了通过遗传修饰技术改善SIT的技术策略,并综合分析了我国开展苹果蠹蛾遗传修饰研究情况和将其应用在苹果蠹蛾防控体系中的可行性及优势。     

Flight tunnel response of codling moth Cydia pomonella to blends of codlemone,codlemone antagonists and pear ester

Upwind orientation flights of codling moth males Cydia pomonella L. to a single source of sex pheromone (E,E)‐8,10‐dodecadienol (codlemone) are significantly reduced when blending it with pheromone antagonists, either with codlemone acetate, (E,E)‐8,10‐dodecadienyl acetate, or with the codlemone isomer (E,Z)‐8,10‐dodecadienol. However, once activated by a pheromone stimulus, males no longer distinguish between a pheromone source and these antagonistic blend sources. This shows that the pheromone stimulus required for the initiation of an upwind flight response differs from the stimulus for maintaining upwind flight and landing at the source. In contrast to pheromone antagonists, males discriminate between pheromone alone and a blend source of pheromone and the plant volatile pear ester, ethyl (2E,4Z)‐2,4‐decadienoate. This indicates a difference in the detection and neural integration of pheromone and plant volatile stimuli.     

苹果蠹蛾性信息素的研究和应用进展

苹果蠹蛾Cydia pomonella (L.)是我国重要的检疫害虫, 在我国仅分布于新疆和甘肃以西局部地区, 但一直保持向我国东部扩张的趋势。在国际上, 利用性信息素监测和迷向防治苹果蠹蛾已经成为一种切实可行并广泛应用的害虫管理技术。本文综述了苹果蠹蛾性信息素的成分鉴定、人工合成和应用情况的研究进展, 指出了目前存在的问题和应用前景, 以期为我国苹果蠹蛾的防控策略的研究和应用提供参考。     

Effect of humidity and a superabsorbent polymer formulation on the efficacy of Heterorhabditis zealandica (Rhabditida: Heterorhabditidae) to control codling moth,Cydia pomonella (L.) (Lepidoptera: Tortricidae)

Adequate moisture levels are required for nematode survival and subsequent efficacy as entomopathogens. Formulation of nematodes aimed at aboveground applications may assist in maintaining such moisture levels. In this study, we report the effects of a superabsorbent polymer formulation, Zeba® on the performance of an entomopathogenic nematode, Heterorhabditis zealandica Poinar, for controlling diapausing codling moth, Cydia pomonella (L.) larvae in cryptic habitats on trees. Water activity (a_w-value) on bark was considered to be an indication of moisture levels on trees in cryptic habitats where codling moth larvae are known to occur, thereby influencing nematode efficacy. H. zealandica was only able to infect codling moth larvae at a_w≥0.92, with a_w50=0.94 and a_w90=0.96. Laboratory experiments in which nematode concentration was investigated indicated a positive linear relationship between the concentration of nematodes applied and the level of control obtained, with the highest level of mortality recorded at 80 IJs/larva, requiring at least 4 h of conditions conducive to nematode activity to ensure infectivity and subsequent efficacy. Further experimentation showed that the use of the Zeba formulation, together with the nematodes, improved the level of control obtained at 60% and 80% RH in the laboratory and that it also enhanced the survival and infection-ability of the nematodes in the field. The study conclusively illustrates that the tested formulation assisted in maintaining adequate moisture levels on the application substratum, as required for nematode survival and subsequent efficacy.     

苹果蠹蛾热激蛋白Hsp90基因的克隆及热胁迫下的表达分析

世界检疫性害虫苹果蠹蛾Cydia pomonella是一种温度耐受可塑性很高的物种。本研究针对温度波动可能导致其耐热性增强的科学问题, 采用生测法鉴定了苹果蠹蛾实验种群的高温耐受阈值, 采用同源克隆、 RACE和实时荧光定量PCR (RT-qPCR)等方法研究了苹果蠹蛾热激蛋白Hsp90基因的应激表达对耐热性的重要作用。高温耐受阈值研究结果表明, 苹果蠹蛾实验种群的死亡率随温度的升高和时间的延长显著性升高, 1-5龄幼虫分别经50℃和52℃高温处理2, 5和10 min后, 3龄幼虫耐热性最差, 5龄幼虫最强。50℃和52℃分别处理10 min和5 min均可导致1-4龄幼虫全部死亡, 而5龄幼虫在这两种处理下仍有25.0%和11.1%的存活率。以35℃处理的5龄雌幼虫为材料克隆苹果蠹蛾Hsp90基因全长cDNA, 结果显示该基因全长为2 470 bp, 完整开放阅读框为2 148 bp, 共编码716个氨基酸, 预测分子量为82.07 kDa, 命名为Cphsp90 (GenBank登录号JN624775)。该基因编码的氨基酸序列与亚洲玉米螟Ostrinia furnacalis和甘蓝夜蛾Mamestra brassicae等昆虫的Hsp90的氨基酸序列一致性高达96%, 表明了Hsp90家族的保守特性。Cphsp90 mRNA的相对表达量在32~44℃高温胁迫下随温度的升高而显著增高, 证实Cphsp90是诱导型热激基因, 且mRNA相对表达量与胁迫程度正相关。Cphsp90基因的表达还具有组织特异性, 35℃处理幼虫的表皮中Cphsp90相对表达量显著高于血淋巴、 脂肪体和中肠, 应激响应最为活跃。与未经温热预处理的昆虫相比, 35℃温热预处理3 h后的5龄幼虫在40, 45和50℃更高的温度胁迫下, Cphsp90 mRNA达到最高表达量所需要的胁迫温度有所提升, 由未经预热处理的40℃处理10 min提高到45℃处理10 min, 这与温热预处理会增强5龄幼虫耐热性的现象相符, 表明Cphsp90基因的响应表达在苹果蠹蛾耐热性及其可塑性过程中发挥重要的作用。     

Oviposition preferences in relation to larval growth rates and survival in the pine beauty moth, Panolis flammea

Abstract. 1. Adult female pine beauty moths, Panolis flammea (D & S), when given a choice of whole plants or needle pairs of four provenances of Lodgepole pine, Pinus contorta (Douglas), laid most eggs on that provenance on which the larvae attained their greatest growth rates.
2. When presented with a greater number of Lodgepole pine provenances and Pinus sylvestris L, P.flammea oviposition preferences reflected the trade-off between growth rate and survival.
3. There is some evidence to suggest that the moths are responding to the monoterpene composition of the plants.
4. Adult moths showed no preference for Lodgepole pine needles of a range of ages (1–4 years), ovipositing uniformly on all age classes.     

幼虫密度对马铃薯块茎蛾生长发育及繁殖的影响

室内观察了块茎中不同虫口密度(5、10、15、20、25、30头/块茎)对马铃薯块茎蛾Phthorimaea operculella(Zeller)生长发育、后代发育和繁殖的影响。结果显示:幼虫密度显著影响马铃薯块茎蛾的生长发育及繁殖。对其生长发育影响的结果表明:幼虫的发育历期(7.1～9.1d)、蛹的历期(8.8～9.9d)、雌雄成虫的历期(分别为6.4～12.9d,6.7～11.6d)随幼虫密度的增加而延长;幼虫存活率(70.3%～93.3%)、蛹的羽化率(69.8%～91.7%)随幼虫密度的增加显著下降;单头蛹重(9.2～11.4mg)、单雌产卵量(136.8～166.0粒)、成虫的雌∶雄比(0.54～2.17)随幼虫密度的增加而下降。对其后代发育及繁殖的影响的结果表明:卵的发育历期(3.0～4.4d)、幼虫的发育历期(6.2～10.8d)、蛹的历期(8.1～10.0d)、雌雄成虫的历期(分别为7.4～11.8d,6.6～10.5d)、世代发育历期(24.4～36.1d)随幼虫密度的增加而从延长;卵的孵化率(73.1%～79.0%)、幼虫存活率(55.0%～96.8%)、蛹的羽化率(63.3%～93.3%)、世代的存活率(25.6%～71.5%)随虫口密度的增加而下降;单头蛹重(8.9～9.9mg)、单雌产卵量(93.5～155.6粒)、成虫的雌∶雄比(0.45～2.20)随虫口密度的增加而下降;种群趋势指数(I)(7.44～76.43)随幼虫密度的增加而下降。马铃薯块茎蛾的饲养密度建议以1头/13.0～26.0g块茎为宜。