离腹寡毛实蝇两性通讯及行为

离腹寡毛实蝇属Bactrocera spp.实蝇对全世界的水果和蔬菜产生巨大的威胁,造成严重的经济损失。传统的杀虫剂化学防治、不育技术(sterile insect technique,SIT)、雄虫灭绝技术(male annihilation technique,MAT)一直是防控大多数实蝇的主要措施,但具有一定的局限性。因此,急需新的环保型防控方法来防治实蝇。为建立基于昆虫行为的防治策略,本文对离腹寡毛实蝇Bactrocera spp.两性的生殖通讯及相关的行为进行了概述。总结了实蝇的交配系统以及雄虫在求偶之前在求偶炫耀场所的一系列行为,阐述了雌虫交配后产卵标记行为和竞争单个产卵位置的行为以及未来的研究方向,将为实蝇害虫综合治理提供新的思路及参考。     

生态因素对蛾类昆虫交配与生殖的影响

对于两性生殖的昆虫而言,两性交配过程是产生后代及维持种群繁衍的必要环节。然而,昆虫的生殖行为经常受到一系列的内部生理因素和外部生态因素的影响,最终导致昆虫的生殖适合度产生差异。本文以蛾类昆虫为例,通过检索国内外文献,分析比较了气候因素(温度、湿度和光照)、生物因素(寄主植物、天敌和共生菌)和农事活动等生态因素对这类昆虫交配行为和生殖适合度的影响。结果表明,这些因子不但影响该类昆虫的交配行为(包括求偶与交配高峰、交配成功率、交配次数和交配持续时间等),还影响其生殖适合度(如产卵前期、产卵期、产卵量、孵化率和寿命等)。这些研究为深入开展蛾类昆虫的生殖行为生态学研究提供理论基础,同时为揭示蛾类昆虫的种群暴发机制以及该类害虫的科学防控提供线索。     

柑橘大实蝇的内生殖系统形态结构

柑橘大实蝇Bactrocera minax(Enderlein),是柑橘的重要害虫。本文基于光学显微镜、扫描电镜、石蜡切片观察,对柑橘大实蝇的内生殖系统形态结构进行研究。结果表明,柑橘大实蝇雌虫内生殖系统主要由卵巢、侧输卵管、中输卵管、受精囊、附腺、前生殖腔(包含布氏交配囊、桑葚腺、生殖腔片)、后生殖腔(阴道和产卵针)组成。雄虫内生殖系统主要由精巢、精泵、输精管、附腺、输入射精管、输出射精管、后附腺和阳茎组成。其雌虫有泄殖腔,位于产卵针前端稍后,雄虫无泄殖腔。雌虫前生殖腔表面被2对肌肉包裹,内部的布氏交配囊、桑葚腺和生殖腔片不易被观察。精泵是一个淡黄色球体,由射精突(精泵内骨骼)、肌纤维(肌肉)、射精囊组成。柑橘大实蝇的内生殖形系统形态结构或组织经过进化,从而适应其伪产卵器的运动、交配、产卵等行为机制。为理解昆虫繁殖生理、进化和多样性,以及昆虫的产卵、交配和代谢物排泄等行为机制提供理论基础。     

章鱼胺对昆虫性信息素感受、生殖行为和精卵排放的调控

章鱼胺在昆虫生殖活动中发挥重要的调控作用。章鱼胺可以降低昆虫对性信息素感受的反应阈值,提高感受的敏感性。章鱼胺与输卵管上皮细胞受体OAMB和Octβ2R结合,激活Ca~(2+)/钙调蛋白依赖性蛋白激酶Ⅱ和蛋白激酶A,可促进肌肉松弛和输卵管管腔液体分泌。章鱼胺还能促进受精囊和卵巢围鞘的收缩。通过雌性生殖系统不同部位收缩与松弛的偶联,实现精卵排放和受精。此外,章鱼胺也可调控昆虫的求偶、抚育等生殖行为,可通过抑制腺苷酸环化酶的活性调节性信息素的合成和交配后效应。章鱼胺调控昆虫性信息素感受、生殖行为和精卵排放的研究虽然取得了显著进展,但相关机理和信号转导途径等仍需进一步探索。章鱼胺对昆虫生殖调控方面的研究将为查明昆虫生殖机制和杀虫剂开发提供重要理论参考。     

昆虫性信息素的应用

用性信息素防治害虫是近些年发展起来的一种治虫新技术。由于它具有高效、无毒、不伤害益虫、不污染环境等优点,国内外对这一新技术的研究和应用都很重视。许多昆虫发育成熟以后能向体外释放具有特殊气味的微量化学物质,以引诱同种异性昆虫前去交配。这种在昆虫交配过程中起通讯联络作用的化学物质叫昆虫性信息素,或性外激素。用人工合成的性信息素或类似物防治害虫时通常叫昆虫性引诱剂,简称性诱剂。昆虫体内产生和分泌的性信息素数量极少（一般每只雌虫为10－’～10－’g左右）,用其防治害虫是不现实的。由于超微量分析仪器的应用和…     

卷蛾科昆虫性信息素及其提取和分离

经过长期艰苦不懈地研究与实践,科学家们发现用卷蛾昆虫性信息素防治害虫是一个行之有效的途径。它具有高效、无毒、不伤害益虫和不污染环境等优点。因此对昆虫性信息素的研究成为科学家们研究的一个重点。１　卷蛾科昆虫的化学通讯与性信息素昆虫交配化学通讯的基本形式是由雌蛾释放一种特异性的性信息素,通过空间弥散,最后达到雄蛾栖息地,雄蛾受性信息素的刺激而产生一系列定向飞行和性行为,达到交配、繁衍后代的目的。鲁洛夫斯（Ｒｏｅｌｏｆｓ,１９７０）把雌蛾性信息素分为两类：一类称作“性信息素的主要活性成分”起刺激雄蛾作…     

影响昆虫产卵行为的因素及其应用研究概述

产卵是昆虫完成个体发育、繁衍后代必经的生命阶段。昆虫在选择适宜产卵场所、做出产卵行为时会因自然环境、寄主本身分泌物以及寄主天敌等因素的影响而发生变化。这些影响因素的改变如果加以合理利用可以成为防治植食性昆虫和更好的发挥寄生性和捕食性天敌昆虫作用的重要途径。因此,本文从产卵抑制信息素、引诱物、学习经历和产卵基质等方面综述了影响昆虫产卵行为的因素,并对其应用做出展望,以期为害虫防控和寄生性、捕食性天敌昆虫的研究和应用提供参考。     

信息化合物对昆虫行为的影响

本文综述了来自寄主植物的挥发性物质和同种昆虫或异种昆虫释放的各种信息素及两者的协同作用的信息化合物对昆虫行为的影响。特别强调了寄主植物的气味物质和昆虫信息素协同作用在昆虫寻找寄主、求偶、交配及天敌在寄主识别过程中的重要地位。昆虫对寄主植物的识别是由于识别了植物气味的由一定组分、按照严格比例组成的化学指纹图。昆虫信息素与植物挥发性物质相结合为昆虫寻找求偶、交配场所提供更复杂或更全面的信息。许多昆虫只有在寄主植物或寄主植物气味存在时 ,才能释放性或聚集信息素。天敌在寄主识别、搜索及定位等一系列过程中 ,来自寄主的食料、寄主本身及两者的互作的信息化合物起重要的作用。研究信息化合物对昆虫行为的影响可以探索昆虫各种行为的内在机理 ,更好的了解寄主—昆虫—天敌三层营养关系的相互作用 ,对利用天然活性化合物防治害虫及生物防治提供理论依据     

昆虫信息化学物质的应用进展

介绍昆虫性信息素(sex pheromone)、示踪信息素(trail pheromone)、聚集信息素(aggregation pheromone)、产卵(oviposition)和产卵忌避(oviposition deterring)信息化合物(semioche micals)和种间协同素(synomone)在害虫控制方面的最新应用进展,其中,重点介绍性信息素在害虫种群监测、大量诱捕和干扰交配3个方面的应用进展情况。与性信息素相比,人们对示踪信息素、聚集信息素、产卵和产卵忌避信息化合物和种间协同素的报道较少,但这些信息素也正在不断的被人们发现和利用。从一种昆虫信息素被鉴定出来,到其在生产当中很好应用,尚有很多问题需要解决,所以,文中对昆虫信息化学物质田间应用效果的影响因子进行分析。     

浅谈昆虫世界的求偶交配行为

在昆虫世界的大观园里,大部分昆虫的受精产卵、生殖繁育都需要经过两性交配的过程才能完成。昆虫种类齐全,求偶行为更是多种多样。本文介绍了几种具有代表性的昆虫的求偶行为。对于昆虫吸引异性,延续种群,繁育后代,并维持物种间的生殖隔离具有重要意义。     

Behavioural switch of female Mediterranean fruit fly, Ceratitis capitata: mating and oviposition activity in outdoor field cages in Hawaii

1 Laboratory-reared normal, and wild female Mediterranean fruit flies, Ceratitis capitata (Wiedemann), were assayed in outdoor field cages to assess the impact of a mating-induced behavioural switch on mating and subsequent oviposition activity. 2 Virgin females preferred interactions with males leading to mating over attraction to, and oviposition in, artificial yellow spheres containing guava odour or green apples hung in a guava tree. Laboratory-reared females previously mated with either laboratory-reared normal males or laboratory-reared irradiated (sterile) males showed little interest in remating with males and instead, were much more likely to be found arrested on artificial and real fruit and ovipositing. Oviposition on artificial fruit was five times greater by females that had mated with either normal or irradiated males than by virgin females. Wild females showed similar qualitative changes in the mating-induced behavioural switch; however, oviposition activity was significantly less than for laboratory-reared females. 3 These results confirm that mating has a profound effect on the behaviour of female Mediterranean fruit flies and that irradiated males are functionally equal with normal males (lab-reared or wild) in their ability to alter female behaviour. These results are discussed in the context of the sterile insect technique for control of Mediterranean fruit flies in the field.     

Physiological status of Drosophila suzukii (Diptera: Drosophilidae) affects their response to attractive odours

An improved understanding of the biology of the invasive pest, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), is critical for the development of effective management strategies. Trapping is one technique used for both detection and control; however, the efficacy of trapping can vary depending on the target insect's physiological state, its behavioural priorities and the type of attractant used in the trap. We conducted a series of caged trapping experiments and a greenhouse trapping experiment to investigate the effects of D. suzukii feeding status, age, mating status, ovipositional status and seasonal morph type on the capture rate of traps baited with fermentation odours. Starved flies were trapped at greater rates compared to fed flies; more virgin flies were trapped than mated flies; flies deprived of an oviposition substrate were trapped more frequently than flies given an oviposition substrate. It is still unclear whether age or seasonal morphology affect bait response. Lastly, a caged choice experiment investigated the relationship between female reproductive status and attraction to fermentation or fruit odours. Fermentation‐based traps captured female flies regardless of their reproductive status but, ripe fruit‐based traps were more attractive to flies with more than seven eggs. In summary, studies that use fermentation‐based traps should recognize that capture rates of D. suzukii will depend on the feeding, mating and oviposition experiences of the population; also, fruit‐based traps may better target gravid females.     

Diel patterns of reproductive activities in the tomato fruit fly, Neoceratitis cyanescens

We describe the diurnal temporal and spatial patterns of reproductive activities (mating and ovipositing) of adult tomato fruit flies, Neoceratitis cyanescens (Bezzi) (Diptera: Tephritidae), under laboratory, field‐cage and field conditions. The distribution pattern of flies in the different habitats (host and non‐host plants) showed temporal, physiological and sexual differences. Mature females were observed to frequent host plants preferentially, particularly in the late afternoon. By contrast, immature females preferred to rest on non‐host plants throughout the day. Males frequented mainly non‐host plants but some were observed on host fruits in the morning. Mating activity took place preferentially on non‐host plants, in the morning. In laboratory cages, females showed a strong daily propensity to engage in mating behaviour; the mean percentage of mating females was 88 ± 5%. Time allotted to this activity (4 h 52 min ± 1 h 23 min in laboratory cages and at least 3 h for the mating pairs observed in the field) appeared considerable compared to the time required to satisfy feeding or oviposition activities. Except for a few ovipositing females observed in the morning, oviposition activities occurred mainly in the late afternoon.     

The importance of pre-and postcopulatory sexual selection promoting adaptation to increasing temperatures

Global temperatures are increasing rapidly affecting species globally. Understanding if and how different species can adapt fast enough to keep up with increasing temperatures is of vital importance. One mechanism that can accelerate adaptation and promote evolutionary rescue is sexual selection. Two different mechanisms by which sexual selection can facilitate adaptation are pre- and postcopulatory sexual selection. However, the relative effects of these different forms of sexual selection in promoting adaptation are unknown. Here, we present the results from an experimental study in which we exposed fruit flies Drosophila melanogaster to either no mate choice or 1 of 2 different sexual selection regimes (pre- and postcopulatory sexual selection) for 6 generations, under different thermal regimes. Populations showed evidence of thermal adaptation under precopulatory sexual selection, but this effect was not detected in the postcopulatory sexual selection and the no choice mating regime. We further demonstrate that sexual dimorphism decreased when flies evolved under increasing temperatures, consistent with recent theory predicting more sexually concordant selection under environmental stress. Our results suggest an important role for precopulatory sexual selection in promoting thermal adaptation and evolutionary rescue.     

Ecological divergence promotes the evolution of cryptic reproductive isolation

Speciation can involve the evolution of 'cryptic' reproductive isolation that occurs after copulation but before hybrid offspring are produced. Because such cryptic barriers to gene exchange involve post-mating sexual interactions, analyses of their evolution have focused on sexual conflict or traditional sexual selection. Here, we show that ecological divergence between populations of herbivorous walking sticks is integral to the evolution of cryptic reproductive isolation. Low female fitness following between-population mating can reduce gene exchange between populations, thus acting as a form of cryptic isolation. Female walking sticks show reduced oviposition rate and lower lifetime fecundity following between-population versus within-population mating, but only for mating between populations using different host-plant species. Our results indicate that even inherently sexual forms of reproductive isolation can evolve as a by-product of ecological divergence and that post-mating sexual interactions do not necessarily evolve independently of the ecological environment.     

Male Sexual Behavior and Pheromone Emission Is Enhanced by Exposure to Guava Fruit Volatiles in Anastrepha fraterculus

Background

Plant chemicals can affect reproductive strategies of tephritid fruit flies by influencing sex pheromone communication and increasing male mating competitiveness.

Objective and Methodology

We explored whether exposure of Anastrepha fraterculus males to guava fruit volatiles and to a synthetic blend of volatile compounds released by this fruit affects the sexual performance of wild and laboratory flies. By means of bioassays and pheromone collection we investigated the mechanism underlying this phenomenon.

Results

Guava volatile exposure enhanced male mating success and positively affected male calling behavior and pheromone release in laboratory and wild males. Changes in male behavior appear to be particularly important during the initial phase of the sexual activity period, when most of the mating pairs are formed. Exposure of laboratory males to a subset of guava fruit volatiles enhanced mating success, showing that the response to the fruit might be mimicked artificially.

Conclusions

Volatiles of guava seem to influence male mating success through an enhancement of chemical and physical signals related to the communication between sexes. This finding has important implications for the management of this pest species through the Sterile Insect Technique. We discuss the possibility of using artificial blends to improve the sexual competitiveness of sterile males.     

Evidence for sexual isolation as a prezygotic barrier to gene flow between morphologically divergent species of Rhagoletis fruit flies

1. Certain groups of fruit flies in the genus Rhagoletis (Diptera: Tephritidae) are exemplars for sympatric speciation via host plant shifting. Flies in these species groups are morphologically similar and overlap in their geographic ranges, yet attack different, non‐overlapping sets of host plants. Ecological adaptations related to differences in host choice and preference have been shown to be important prezygotic barriers to gene flow between these taxa, as Rhagoletis flies mate on or near the fruit of their respective host plants. Non‐host‐related assortative mating is generally absent or present at low levels between these sympatrically diverging fly populations. 2. However, some Rhagoletis taxa occasionally migrate to ‘non‐natal’ plants that are the primary hosts of other, morphologically differentiated fly species in the genus. These observations raise the question of whether sexual isolation may reduce courtship and copulation between morphologically divergent species of Rhagoletis flies, contributing to their prezygotic isolation along with host‐specific mating. 3. Using reciprocal multiple‐choice mating trials, we measured sexual isolation among nine species pairs of morphologically differentiated Rhagoletis flies. Complete sexual isolation was observed in eight of the nine comparisons, while partial sexual isolation was observed in the remaining comparison. 4. We conclude that sexual isolation can be an effective prezygotic barrier to gene flow contributing to substantial reproductive isolation between many morphologically distinct Rhagoletis species, even in the absence of differential host plant choice and host‐associated mating.     

Behavioral genetics of Drosophila ananassae

Drosophila ananassae has a unique status among Drosophila species because of certain peculiarities in its genetic behavior. The most unusual feature of this species is its relatively high frequency of spontaneous male recombination. The results of studies on non-sexual behavior, such as phototactic responses, eclosion rhythm, and preferences for oviposition and pupation sites, lead us to suggest that this behavior is under polygenic control, with a substantial amount of additive genetic variation. Sexual isolation has been reported in D. ananassae with the degree of such isolation being stronger in isofemale lines than in natural populations. The significant variations seen in the mating propensity of several isofemale strains, inversion karyotypes and wild type strains, the diminishing effects of certain mutations on the sexual activity of males, and the positive responses to selection for high and low mating propensity point to a genetic control of sexual behavior in D. ananassae. Males contribute more to variation and thus are more subject to intrasexual selection than females. There is a positive correlation between sternopleural bristle number, mating propensity and fertility in D. ananassae. This correlation between morphometric traits and mating success suggests that larger flies are more successful in mating than smaller ones. There is also evidence for adaptive plasticity and a trade-off between longevity and productivity in D. ananassae. Rare, specific courtship song parameters that provide males with a mating advantage have also been reported in different geographic strains of D. ananassae. The remating behavior of males and females, sperm displacement, and the bi-directional selection for female remating speed indicate that post-mating behavior in this species may also be under genetic control. The occurrence of size assortative mating further indicates that there is size-dependent sexual selection in D. ananassae.     

Mating success and oviposition of a butterfly are not affected by non-lethal tissue sampling

Non-lethal methods of tissue sampling are increasingly used for genetic studies of insect species and the effects of this approach have long been assumed to be minimal. Tissue removal has the potential to influence insect reproductive behaviours such as mate recognition, courtship or oviposition but the effects of non-lethal sampling on reproductive success have not been widely and adequately tested. Here, we test potential effects of both wing-clipping and leg removal on reproductive behaviours of the cabbage white butterfly (Pieris rapae). We conducted a total of 93 male and 59 female mating trials, and found no significant differences in mating success between treated (i.e., tissue removed) and control individuals in either sex. We also monitored the number and location of eggs laid by 58 females. We found no significant differences in egg-laying behaviour among leg removed and control individuals. Power analysis indicated that we had sufficient statistical power to detect moderate effects of treatment on both mating and oviposition. Our study provides the most comprehensive examination to date of the effects of non-lethal sampling on reproductive behaviours in a butterfly/insect species, and supports the contention that tissue sampling is non-detrimental. To fully comprehend the general impacts of tissue sampling on butterfly reproductive behaviour however, additional similar studies need to be conducted on a variety of species with differing mating behaviours. Only through meta-analysis, may it be possible to detect more subtle effects of tissue removal which cannot be revealed within a single study due to sample size limitations.     

Promiscuous mating in the harem-roosting fruit bat, Cynopterus sphinx

Observations on mating behaviours and strategies guide our understanding of mating systems and variance in reproductive success. However, the presence of cryptic strategies often results in situations where social mating system is not reflective of genetic mating system. We present such a study of the genetic mating system of a harem-forming bat Cynopterus sphinx where harems may not be true indicators of male reproductive success. This temporal study using data from six seasons on paternity reveals that social harem assemblages do not play a role in the mating system, and variance in male reproductive success is lower than expected assuming polygynous mating. Further, simulations reveal that the genetic mating system is statistically indistinguishable from promiscuity. Our results are in contrast to an earlier study that demonstrated high variance in male reproductive success. Although an outcome of behavioural mating patterns, standardized variance in male reproductive success (I(m)) affects the opportunity for sexual selection. To gain a better understanding of the evolutionary implications of promiscuity for mammals in general, we compared our estimates of I(m) and total opportunity for sexual selection (I(m) /I(f), where I(f) is standardized variance in female reproductive success) with those of other known promiscuous species. We observed a broad range of I(m) /I(f) values across known promiscuous species, indicating our poor understanding of the evolutionary implications of promiscuous mating.