蜜源食物对节肢动物天敌寿命、繁殖力和控害能力的影响

大多数节肢动物天敌除了寄生或捕食寄主或猎物外,也会取食蜜源食物,特别是包括植物花蜜、花外蜜和昆虫蜜露等富含糖分的食物。这些蜜源食物对于提高寄生性和捕食性天敌的飞行和寄主搜索能力、延长寿命、提高繁殖力和增强控害能力都能发挥重要作用。本文重点介绍了农田生态系统中3类常见的非猎物性蜜源食物即植物花蜜、花外蜜和昆虫蜜露。其中,花蜜和花外蜜能够显著延长天敌寿命,提高天敌繁殖力和控害能力;蜜露的作用虽次于花蜜和花外蜜,但仍能促进某些天敌的生态功能。还进一步综述了显花植物和蜜源食物投放在生物防治中的应用,并从筛选适宜的蜜源植物、蜜源食物中糖成分作用分析和天敌对蜜源食物的搜索和定位等方向开展对蜜源食物的研究利用进行了展望。     

蚂蚁与排泄蜜露的同翅目昆虫的相互作用及其生态学效应

同翅目昆虫多为植食性害虫,但有些种类也是重要的经济昆虫。以蜜露为纽带,蚂蚁与排泄蜜露的同翅目昆虫在漫长的进化过程中逐渐形成了复杂而密切的关系。研究蚂蚁-同翅目昆虫之间的相互作用,有选择的防治或保护某些同翅目昆虫,并控制其在寄主植物上的数量,可提高经济效益。本文介绍蚂蚁与排泄蜜露的同翅目昆虫的相互作用,以及相互作用对节肢动物群落和寄主植物产生的生态学效益,提出研究过程中的不足,并探讨蚂蚁-同翅目昆虫之间的相互作用在生物防治、生物多样性及生态系统功能方面的重要意义,以促进种间关系研究的进一步发展。     

柑橘木虱蜜露排泄机制:进展与展望

半翅目昆虫柑橘木虱Diaphorina citri是柑橘类果树重要害虫,主要以高渗透压的植物韧皮部汁液为食,是柑橘毁灭性病害——柑橘黄龙病(HLB)的主要传播媒介。柑橘木虱取食韧皮部汁液时自身进化出一套完整的渗透调节机制调节其体内渗透压,将体内过量摄入的糖类转化成长链寡糖并以蜜露形式排出体外。本文从柑橘木虱蜜露排泄行为、蜜露组成成分以及影响蜜露排泄的多个因素进行了论述,同时综述了可能参与柑橘木虱蜜露排泄行为的渗透调节基因。研究表明,柑橘木虱雌雄成虫及若虫在蜜露排泄行为上存在显著差异,且排泄的蜜露在颜色、纹路及组成成分方面均有不同;寄主植物、杀虫剂、病原微生物及天敌化合物均会影响柑橘木虱蜜露排泄行为。分子机制探究发现,α-葡萄糖苷水解酶、水通道蛋白及糖基转移酶基因等关键渗透调节基因可能参与调控柑橘木虱蜜露排泄行为。本文可为未来有关柑橘木虱蜜露排泄行为方面的研究以及为研制柑橘木虱防治新型药剂开发新靶标提供参考。     

蜜粉源植物对天敌昆虫的作用及其在生物防治中的应用

寄生性和捕食性天敌昆虫成虫普遍存在通过取食蜜粉源植物补充营养的行为,这可不同程度地促进天敌昆虫性成熟、延长其寿命、提高其生殖力或寄生率,以及搜寻寄主效率和子代雌性比率,从而显著提高天敌昆虫在生物防治中的控害能力和效果。蜜粉源植物花的结构及植物对天敌昆虫产生的嗅觉、视觉信号和花蜜花粉对天敌昆虫产生的味觉信号又显著影响天敌昆虫选择蜜粉源植物的行为和结果。但是,蜜粉源植物也可成为害虫的补充营养植物,从而提高害虫的为害能力。因此,需深入研究不同蜜粉源植物对天敌昆虫及害虫的作用,趋利避害,才可能应用蜜粉源植物成功调控天敌与害虫的益害比,实现害虫的可持续控制。     

替代性饲料及人工饲料对捕食性天敌昆虫生命参数影响的研究进展

捕食性昆虫如捕食性甲虫和捕食性蝽类是许多农林害虫的重要天敌昆虫,在生物防治中发挥着重要的作用。批量化生产高质量的自然天敌是实现生物防治的重要支撑技术之一,捕食性昆虫的替代饲料和人工饲料近几年已进行了广泛研究。本文总结了国内外替代性饲料和人工饲料对捕食性天敌甲虫及蝽的主要生命参数的影响。     

基于CNKI分析的我国农田捕食性昆虫资源与应用

【目的】了解我国农田捕食性昆虫资源与应用研究态势。【方法】应用文献计量学方法,分析中国知网(CNKI)收录的全部年代的我国农田捕食性昆虫的中文文献。【结果】提取到544篇与农田捕食性昆虫相关文献及包含在这些文献中的1 747条关键信息词,研究内容主要包括以下5个方面:农田节肢动物群落与捕食性优势种;农田重要捕食者;捕食作用、食物网关系与生态服务价值评价;人工繁育、人工饲料与天敌释放应用;主要农作物的重要害虫种群及其综合管理。水稻与棉花生态系统及其中的捕食昆虫与害虫被重点关注。异色瓢虫Harmoniaaxyridis、七星瓢虫Coccinellaseptempunctata、龟纹瓢虫Propyleajaponica、黑肩绿盲蝽Cyrtorhinuslividipennis、青翅蚁形隐翅虫Paederusfuscipes、稻红瓢虫Micraspisdiscolor、尖钩宽黾蝽Microveliahorvathi等是农田中的优势性捕食性昆虫。【结论】在我国主要农田生态系统中,存在着丰富的捕食性昆虫资源,它们扮演着农作物害虫天敌的角色,实现对农作物害虫的生物防治或自然控制。建议加强对重要害虫种群发生机制研究,促进有利于天敌生存、保存的条件与方法研究,提高天敌的生态防控效能。     

不同营养源对稻虱缨小蜂寿命及寄生能力的影响

研究了蜂蜜、玉米花粉、大豆花、褐飞虱蜜露和黄脊飞虱蜜露对稻虱缨小蜂寿命、寄生能力以及寄生行为对稻虱缨小蜂寿命和存活率的影响。结果表明,蜂蜜、玉米花粉、褐飞虱蜜露和大豆花均能明显延长稻虱缨小蜂的寿命。并且显著地提高了对褐飞虱卵的寄生能力,其中蜂蜜最有效,大豆花次之,玉米花粉和褐飞虱蜜露这两种营养源以玉米花粉(水和褐飞虱蜜露+水的形式)对提高稻虱缨小蜂寿命最有效,而单一玉米花粉、花粉液、褐飞虱蜜露稀释液和纯褐飞虱蜜露均不能延长稻虱缨小蜂寿命,黄脊飞虱蜜露对稻虱缨小蜂的寿命和寄生能力均无影响。寄生行为对稻虱缨小蜂的寿命基本无影响。但致使其40～48h内的存活率提高,此后的存活率降低较快,在稻田周围的作物和植被上调查到约10种飞虱,非稻田生境能为稻田寄生性天敌提供寄主和食物,是理想的庇护所,对保护和提高稻田天敌种群数量,提高稻田天敌的生物控制作用。     

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。     

昆虫蜜露研究方法

本文在概述昆虫蜜露的分泌节律、组成成分以及生态学意义等的基础上,全面介绍了昆虫蜜露的定性和定量研究方法。详述了显色法、称量法、比色法、油滴法和蜜露钟法的具体步骤、注意事项和实例,并比较了这5种检测方法的优缺点,供相关工作者使用时参考。     

多寄主型寄生性天敌昆虫的寄主适应性及其影响因素

寄生性天敌昆虫对不同寄主资源的适应能力是其存活和繁殖的必要条件,它们的寄主选择行为则是其重要的适应结果。多寄主型寄生性天敌昆虫虽然对某种特定寄主资源的利用效率可能不如单寄主型寄生蜂,但却有利于拓展更宽的寄主范围,因此对环境的适应能力更强,更容易在自然界维持其种群的生存。统计结果也表明多寄主型天敌的生物防治效果往往比专食性天敌更高。有时生物防治成功的关键可能并不在于所利用的天敌种类的不同,而在于天敌的不同生物型或地理宗。总结了多寄主型寄生性天敌昆虫的寄主适应能力及其影响因素。寄生性天敌昆虫不仅因地理隔离产生种群分化,也可能因寄生不同的寄主产生种群内的分化,从而更加适应寄主的生活特性和栖境条件。寄主种类、寄主发育阶段、寄主大小、寄主营养、寄主免疫反应、寄主逃避反应、其它天敌的竞争、寄主共生或共栖生物的存在、寄主植物、天敌自身的学习能力及其共生微生物等多种因素对寄生性天敌昆虫的寄主适应性可产生影响。展望了多寄主型寄生性天敌昆虫对新寄主资源的拓展利用能力和适应性在生产上的可能应用前景和途径,以期为明确天敌与寄主间的互作关系,人工驯化寄生性天敌昆虫增强对靶标害虫的控制作用,合理利用天敌提高生物防治效率提供新的思路和理论支持。     

杀虫剂使用失当是甜菜夜蛾大发生的重要原因

近年来,甜菜夜蛾Spodoptera exigua(H櫣bner)在我国的危害面积越来越广,造成的损失越来越大。为了更好地了解甜菜夜蛾的发生和成灾规律,改善和提高预测与防治技术,文章就杀虫剂对甜菜夜蛾及其天敌的影响进行了分析。结果表明,杀虫剂使用失当是甜菜夜蛾大发生的重要原因。甜菜夜蛾对杀虫剂的抗药性水平超过天敌,而天敌的飞行、搜索、攻击和产卵等行为,以及生长、发育、生殖和寿命等又容易受杀虫剂的干扰,产生负面影响,从而降低天敌对甜菜夜蛾的控制能力。因此,如何合理使用杀虫剂,在有效控制甜菜夜蛾种群的同时,达到保护天敌的目的,将是我们面临的新课题。     

Honeydew composition and its effect on life-history parameters of hyperparasitoids

1. Diets that maximise life span often differ from diets that maximise reproduction. Animals have therefore evolved advanced foraging strategies to acquire optimal nutrition and maximise their fitness. The free-living adult females of parasitoid wasps (Hymenoptera) need to balance their search for hosts to reproduce and for carbohydrate resources to feed. 2. Honeydew, excreted by phloem-feeding insects, presents a widely available carbohydrate source in nature that can benefit natural enemies of honeydew-producing insects. However, the effects of variation in honeydew on organisms in the fourth trophic level, such as hyperparasitoids, are not yet understood. 3. This study examined how five different honeydew types influence longevity and fecundity of four hyperparasitoid taxa. Asaphes spp. (Pteromalidae) and Dendrocerus spp. (Megaspilidae) are secondary parasitoids of aphid parasitoids and are thus associated with honeydew-producing insects. Gelis agilis and Acrolyta nens (both Ichneumonidae) are secondary parasitoids of species that do not use honeydew-producing hosts. 4. Most honeydew types had a positive or neutral effect on life span and fecundity of hyperparasitoids compared with controls without honeydew, although negative effects were also found for both aphid hyperparasitoids. Honeydew produced by aphids feeding on sweet pepper plants was most beneficial for all hyperparasitoid taxa, which can partially be explained by the high amount of honeydew, but also by the composition of dietary sugars in these honeydew types. 5. The findings of this study underline the value of aphid honeydew as a carbohydrate resource for fourth-trophic-level organisms, not only those associated with honeydew-producing insects but also ‘interlopers’ without such a natural association.     

Impacts of Argentine ants on mealybugs and their natural enemies in California's coastal vineyards

Abstract 1. The Argentine ant, Linepithema humile, tends honeydew‐excreting homopterans and can disrupt the activity of their natural enemies. This mutualism is often cited for increases in homopteran densities; however, the ant’s impact on natural enemies may be only one of several effects of ant tending that alters insect densities. To test for the variable impacts of ants, mealybug and natural enemy densities were monitored on ant‐tended and ant‐excluded vines in two California vineyard regions. 2. Ant tending increased densities of the obscure mealybug, Pseudococcus viburni, and lowered densities of its encyrtid parasitoids Pseudaphycus flavidulus and Leptomastix epona. Differences in parasitoid recovery rates suggest that P. flavidulus was better able to forage on ant‐tended vines than L. epona. 3. Densities of a coccinellid predator, Cryptolaemus montrouzieri, were higher on ant‐tended vines, where there were more mealybugs. Together with behavioural observations, the results showed that this predator can forage in patches of ant‐tended mealybugs, and that it effectively mimics mealybugs to avoid disturbance by ants. 4. Ant tending increased densities of the grape mealybug, Pseudococcus maritimus, by increasing the number of surviving first‐instar mealybugs. Parasitoids were nearly absent from the vineyard infested with P. maritimus. Therefore, ants improved either mealybug habitat or fitness. 5. There was no difference in mealybug distribution or seasonal development patterns on ant‐tended and ant‐excluded vines, indicating that ants did not move mealybugs to better feeding locations or create a spatial refuge from natural enemies. 6. Results showed that while Argentine ants were clearly associated with increased mealybug densities, it is not a simple matter of disrupting natural enemies. Instead, ant tending includes benefits independent of the effect on natural enemies. Moreover, the effects on different natural enemy species varied, as some species thrive in the presence of ants.     

寄主植物-蚜虫-天敌三重营养关系的化学生态学研究进展

综述了寄主植物－蚜虫－天敌三重营养关系的化学生态学研究,重点阐述了3个研究热点：①植物挥发性物质在蚜虫及其天敌选择寄主行为过程中的作用;②蚜虫信息素和蜜露对蚜虫天敌寄主选择行为的影响;③植物挥发性物质对蚜虫信息系作用的影响。对寄主植物－蚜虫－天敌三重营养关系的全面了解,将为蚜虫的综合治疗提供新思维。     

Predicting the effects of climate change on natural enemies of agricultural pests

Climate change can have diverse effects on natural enemies of pest species. Here we review these effects and their likely impacts on pest control. The fitness of natural enemies can be altered in response to changes in herbivore quality and size induced by temperature and CO₂ effects on plants. The susceptibility of herbivores to predation and parasitism could be decreased through the production of additional plant foliage or altered timing of herbivore life cycles in response to plant phenological changes. The effectiveness of natural enemies in controlling pests will decrease if pest distributions shift into regions outside the distribution of their natural enemies, although a new community of enemies might then provide some level of control. As well as being affected by climate through host plants and associated herbivores, the abundance and activity of natural enemies will be altered through adaptive management strategies adopted by farmers to cope with climate change. These strategies may lead to a mismatch between pests and enemies in space and time, decreasing their effectiveness for biocontrol. Because of the diverse and often indirect effects of climate change on natural enemies, predictions will be difficult unless there is a good understanding of the way environmental effects impact on tritrophic interactions. In addition, evolutionary changes in both hosts and natural enemies might have unexpected consequences on levels of biocontrol exerted by enemies. We consider interactions between the pest light brown apple moth and its natural enemies to illustrate the type of data that needs to be collected to make useful predictions.     

Ants impact the energy reserves of natural enemies through the shared honeydew exploitation

1. Ants, as well as many species of parasitoids and predators, rely on sugar‐rich foods such as honeydew to fulfill their energetic needs. Thus, ants and natural enemies may interact through the shared honeydew exploitation. 2. Ant‐exclusion experiments were performed in a citrus orchard to test the hypothesis that ants may impact the energy reserves of predators and parasitoids through the competition for honeydew. Through the use of high‐performance liquid chromatography (HPLC) the level of ant activity with the energy reserves and feeding history of individual specimens collected in the field during representative days of spring, summer, and autumn were related. 3. Out of 145 Aphytis chrysomphali Mercet parasitoids captured in the field, 65% were classified as sugar‐fed and 24.7% as honeydew‐fed. In summer, when ant activity peaked, there was a significant negative correlation between the level of ant activity and the total sugar content and honeydew feeding incidence by A. chrysomphali. Out of 47 individuals of the predator Chrysoperla carnea sensu lato (Stephens), captured in the field, 55.3% were classified as sugar‐fed. We found a significant negative effect of the level of ant activity on the sugar‐feeding incidence by C. carnea in spring. 4. The present study provides evidence that ants can interfere with the energy reserves of natural enemies. This interaction may be widespread in various ecosystems with important consequences for the arthropod community composition and with practical implications for biological control given that absence of sugar feeding is detrimental for the fitness of many species of predators and parasitoids.     

Influence of macronutrient imbalance on native ant foraging and interspecific interactions in the field

1. Ants interact with a diversity of organisms. These interactions, coupled with their abundance, cause ants to have ecologically important effects across multiple trophic levels. 2. Empirical study of ant nutritional ecology has led to the prediction that a macronutrient imbalance will affect ant behaviour and interspecific interactions that underlie these broad‐scale effects. Excess carbohydrate relative to protein is predicted to increase ant aggressiveness, predatory tendency and foraging activity, and to decrease collection of hemipteran honeydew and plant nectar. 3. In field experiments conducted in 2009 and 2010, captive colony fragments of a native ant, Formica podzolica (Hymenoptera: Formicidae), were provided with either simulated prey or carbohydrate solution ad libitum. Foraging behaviours and interactions with flowers, myrmecophilous aphids and aphid natural enemies on wild‐grown plants were documented. 4. Strong effects of macronutrient imbalance on foraging manifested quickly and consistently across colonies; in accordance with predictions, prey‐fed foragers collected both honeydew and floral nectar, whereas carbohydrate‐fed ants ceased collecting these resources. Counter to predictions, carbohydrate‐fed ants dramatically lowered their activity levels and did not prey upon aphids. 5. Ants had no effect on aphid enemies in 2009, when the latter were relatively rare, but decreased their abundance in 2010. Despite this protection, the net effect of ants on aphids was negative (measured only in 2009). Prey‐fed ants demonstrated a strong preference for honeydew over floral nectar, thus demonstrating that a macronutrient imbalance may lead to different interactions with similar resources. 6. This study links ant nutrition and community ecology by demonstrating the rapid, asymmetric and multitrophic consequences of nutritionally mediated behaviour.     

The use of kairomones for foraging decisions by an aphid parasitoid in small host aggregations

1. The wasp Diaeretiella rapae uses honeydew emitted by its host, the cabbage aphid Brevicoryne brassica, as a kairomone (chemicals emitted by an organism as part of its activity and used by its natural enemies to their advantage). The role of the kairomone in foraging decisions by the parasitic wasp was explored by manipulating the amount of honeydew and the number of aphids in a colony independently. The count-down patch-exploitation mechanism (Iwasa et al., 1981) was employed to predict the results of these manipulations and contrast them with the predictions of Waage's (1979) model. 2. Kairomonal activity of honeydew decreased as the honeydew aged and lost its activity completely within 72 h. 3. The wasp was exposed to different amounts of honeydew on (a) aphid-free leaves and (b) leaves bearing colonies of 150 aphids. The parasitoid search time on both leaf types increased with increasing honeydew contamination. On aphid-bearing leaves, the number of attacked aphids in the colonies also increased with increasing honeydew contamination. The presence of aphids reduced the parasitoid search time compared to search time on aphid-bearing leaves with the same level of honeydew contamination, as predicted by the count-down model. 4. Parasitoids exposed to the same amount of honeydew, but a different number of aphids in a colony on the leaf, first increased the number of aphids attacked in relation to the number of aphids in the colony. But as the colony reached a certain size, the number of aphids attacked levelled off, despite the increase in the number of aphids in the colony. Search time was variable but did not exhibit any trend as the number of aphids in the colonies increased. 5. These results suggest that honeydew level is used by D. rapae as a cue for assessment of the number of aphids in the colony. In such cases, a count-down exploitation mechanism gives the best results to a forager. Many parasitoids may use kairomones for patch assessment and will therefore employ a count-down rule during patch exploitation.