两种植绥螨的同类相残和集团内捕食作用

巴氏新小绥螨(Neoseiulus barkeri)和黄瓜新小绥螨(N.cucumeris)是两种多食性植绥螨,主要捕食叶螨和蓟马等,目前在我国广泛应用于农业生物防治中.本文研究了这两种植绥螨种内的同类相残(cannibalism)和种间的集团内捕食作用(intraguild predation)以及相互之间的攻击强度,以明确两者之间的相互关系,为合理构建天敌组合及评估生物防治的作用提供依据.结果显示:两种植绥螨对同种或异种幼螨的捕食量最大,其次是若螨,而对卵的捕食量极低.两种植绥螨对异种幼螨或若螨的捕食量均极显著高于对同种幼螨或若螨的捕食量.可见,无其他猎物存在情况下,两种植绥螨同时发生时更倾向于发生种间的集团内捕食.而巴氏新小绥螨对异种幼螨或若螨的捕食量均高于黄瓜新小绥螨对异种幼螨或若螨的捕食量,并且巴氏新小绥螨和黄瓜新小绥螨相比,巴氏新小绥螨对异种幼螨的攻击性更强,因此当这两种植绥螨发生集团内捕食时,巴氏新小绥螨是潜在的集团内捕食者,而黄瓜新小绥螨是潜在的集团内猎物.     

昆虫群落中的集团内捕食作用

与捕食、竞争等种间关系相比 ,集团内捕食作用是一种更为复杂的种间关系 ,广泛存在于各种生态系中。该文从它的概念、类型、作用特点、与其它种间关系的区别、存在的广泛性、发生强度的影响因素、化学信息调控及其对生物防治效果的影响等几个方面介绍了天敌群落中的这一典型的种间相互关系。根据参与者在集团内捕食作用关系中的利益地位的不同 ,可将集团内捕食作用分为单向性和双向性的 ,也可分成对称性的和不对称性的。参与者的生物学特性和各种环境条件对集团内捕食作用的发生程度和结果起着重要的调控作用。在多种天敌存在的系统中 ,集团内捕食作用影响着目标生物种群动态及其生物防治的效果。深入地研究这一种间关系对增强生物控害的功能有十分重要的意义     

多异瓢虫与七星瓢虫、大草蛉不同虫态间的集团内捕食

多异瓢虫、七星瓢虫和大草蛉是控制蚜虫重要的广谱捕食性天敌昆虫,为明确这些昆虫间的集团内捕食效应与个体发育阶段的关系,观察了多异瓢虫与七星瓢虫、大草蛉各虫态(蛹除外)之间的集团内捕食效应。设置30个虫态(虫龄)组合处理,于温室盆栽棉花(无蚜虫)上接种等量的试虫,观察24 h后的存活数量。结果表明,当参与双方的虫态不同时,晚期虫态的存活数量显著大于早期虫态;当参与双方的幼虫龄期不同时,高龄幼虫的存活数量显著大于低龄幼虫;成虫对卵、1龄和4龄幼虫的捕食程度随虫龄增大而呈抛物线增大,存在显著的二次函数关系。当参与双方的虫态(龄)相同时,多异瓢虫成虫的存活数量显著小于七星瓢虫,但大于大草蛉成虫;多异瓢虫幼虫(1龄和4龄)的存活数量显著小于大草蛉,而与七星瓢虫没有显著差异。研究结果说明,在没有集团外猎物(蚜虫)存在的情况下,多异瓢虫与七星瓢虫、大草蛉之间的集团内捕食效应只在参与者的虫态或虫龄不同时取决于发育阶段,而当参与者虫态或虫龄相同时,还取决于其他因素。     

Diet‐dependent intraguild predation between the predatory mites Neoseiulus californicus and Neoseiulus cucumeris

Based on the hypothesis that matching diets of intraguild (IG) predator and prey indicate strong food competition and thus intensify intraguild predation (IGP) as compared to non‐matching diets, we scrutinized diet‐dependent mutual IGP between the predatory mites Neoseiulus cucumeris and N. californicus. Both are natural enemies of herbivorous mites and insects and used in biological control of spider mites and thrips in various agricultural crops. Both are generalist predators that may also feed on plant‐derived substances such as pollen. Irrespective of diet (pollen or spider mites), N. cucumeris females had higher predation and oviposition rates and shorter attack latencies on IG prey than N. californicus. Predation rates on larvae were unaffected by diet but larvae from pollen‐fed mothers were a more profitable prey than those from spider‐mite fed mothers resulting in higher oviposition rates of IG predator females. Pollen‐fed protonymphs were earlier attacked by IG predator females than spider‐mite fed protonymphs. Spider mite‐fed N. californicus females attacked protonymphs earlier than did pollen‐fed N. californicus females. Overall, our study suggests that predator and prey diet may exert subtle influences on mutual IGP between bio‐control agents. Matching diets did not intensify IGP between N. californicus and N. cucumeris but predator and prey diets proximately influenced IGP through changes in behaviour and/or stoichiometry.     

有益真绥螨与巴氏新小绥螨的集团内捕食和同类相残作用

【目的】有益真绥螨Euseius utilis是北方地区广泛分布的一种多食性植绥螨,而巴氏新小绥螨Neoseiulus barkeri目前在我国广泛应用于农业害虫的生物防治中。本研究旨在对巴氏新小绥螨在本地的应用进行风险评估及为与有益真绥螨的联合释放提供依据。【方法】本研究在室内通过一系列实验,比较了实验室饲养的巴氏新小绥螨和采自内蒙古农业大学校园的有益真绥螨的雌成螨对同种或异种未成熟螨的捕食量、存活时间及产卵量的差异,检测了有益真绥螨与巴氏新小绥螨两种植绥螨相互之间的攻击强度以及种内和种间的相互作用。【结果】两种植绥螨都难以刺吸同种或异种植绥螨的卵,而对同种或异种植绥螨幼螨的捕食量最大,其次是对若螨。在无共同食物的情况下,有益真绥螨雌成螨对同种植绥螨幼螨的攻击性比对异种植绥螨幼螨的攻击性强(BreslowDay检验:χ~2=13.84,df=1,P0.001),且有益真绥螨对同种植绥螨幼螨的捕食量(9.10±1.65头)高于对异种植绥螨幼螨的捕食量(5.31±1.43头)(T检验:t=5.487,P0.001),巴氏新小绥螨对异种植绥螨幼螨的捕食量(7.48±0.75头)高于对同种植绥螨幼螨的捕食量(4.75±0.58头)(T检验:t=9.110,P0.05)。【结论】有益真绥螨更倾向于捕食同种幼螨而发生同类相残;巴氏新小绥螨更倾向于捕食异种幼螨而发生集团内捕食。     

不同猎物及密度对巴氏新小绥螨和拉戈钝绥螨同类相残和集团内捕食作用的影响

明确不同猎物及密度下巴氏新小绥螨Neoseiulus barkeri与拉戈钝绥螨Amblyseius largoensis(Muma)的同类相残和集团内捕食作用,为其协同应用控制橡胶树害螨提供依据.在室温27±1℃、湿度75％±5％、光周期12 L∶12D 条件下,以六点始叶螨 Eotetranvchus sexmac...     

Intraguild interactions between the predator Macrolophus pygmaeus and the parasitoid Eretmocerus mundus,natural enemies of Bemisia tabaci

The native parasitoid Eretmocerus mundus Mercet and the predator Macrolophus pygmaeus Rambur are widely used to control Bemisia tabaci (Gennadius) in Mediterranean tomato greenhouses. An optimal biological control strategy for B. tabaci should take into account intraguild interactions between these natural enemies. In this study, predator's prey preferences and prey consumption were studied when offered different parasitoid and whitefly stages. The effect of the host plant on the adults of both natural enemies was also examined. M. pygmaeus preferred to consume B. tabaci over E. mundus when immature stages and adults of B. tabaci and E. mundus were offered. They consumed a larger amount of healthy B. tabaci nymphs and adults than of parasitised nymphs or E. mundus adults. The predator M. pygmaeus interfered with the reproduction of E. mundus females on cotton but not on tomato. However, B. tabaci nymphal mortality on tomato associated with parasitoid host feeding was also lower when the adult parasitoids coexisted with the predators. The joint release of M. pygmaeus and E. mundus adults did not increase the control of the whitefly B. tabaci.     

Intraguild Predation among the Hoverfly Episyrphus balteatus de Geer (Diptera: Syrphidae) and Other Aphidophagous Predators

Aphidophagous predators compete for the same prey species. During their foraging activity they frequently encounter heterospecific aphid predators. These situations can lead to intraguild predation and may disrupt biological control efforts against aphids where more than one predator species is present. We investigated the behavior of larvae of the hoverfly Episyrphus balteatus de Geer and its interaction with three other aphid predators: the ladybird Coccinella septempunctata L., the lacewing Chrysoperla carnea Stephens, and the gall midge Aphidoletes aphidimyza (Rondani). Interspecific interactions between predators were examined in arenas of different sizes and in the presence of extraguild prey. The outcome of interactions between E. balteatus larvae and the other predators depended predominantly on the relative body size of the competitors. Relatively large individuals acted as intraguild predators, while relatively smaller individuals became intraguild prey. Eggs and first- as well as second-instar larvae of E. balteatus were highly susceptible to predation by all other predators, whereas pupae of E. balteatus were preyed upon only by the larvae of C. carnea. Interactions between A. aphidimyza and E. balteatus were asymmetric and always favored the latter. Eggs and first- as well as second-instar larvae of E. balteatus sustained intraguild predation irrespective of the size of the arena or the presence of extraguild prey. However, the frequency of predation on third-instar larvae of E. balteatus was significantly reduced. This study indicated that the same species can be both intraguild predator and intraguild prey. It is suggested that combinations of predators must be carefully chosen for success in biological control of aphids.     

Intraguild predation of Planococcus ficus parasitoids Anagyrus pseudococci and Leptomastix dactylopii by Nephus kreissli

Intraguild predation of the mealybug parasitoids Anagyrus pseudococci (Girault), and Leptomastix dactylopii Howard (Hymenoptera: Encrytidae) by Nephus kreissli Fürsch & Uygun (Coleoptera: Coccinellidae) was studied. The latter is a native predator of the important pest Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae) on grapevines in Turkey. For this purpose, P. ficus of different ages parasitised by A. pseudococci or L. dactylopii, or by both A. pseudococci and L. dactylopii, were served to fourth instars and adults of N. kreissli as food. Experiments were conducted using two different treatments: no-choice (served unparasitised or only one stage of parasitised mealybug) and choice (served unparasitised and only one age of parasitised mealybug together), under controlled environmental conditions. Both fourth instars and adult predators were fed on two- and four-day-old mealybugs parasitised by A. pseudococci or on two-, four- and six-day-old mealybugs parasitised by L. dactylopii or by either A. pseudococci or L. dactylopii. The predators could not consume six-day-old mealybugs parasitised by A. pseudococci, eight-day-old mealybugs parasitised by L. dactylopii, or those parasitised by either of these parasitoids which had become mummified. While it was found that the adult predators preferred parasitised mealybugs to unparasitised, the larvae did not show a pronounced preference between parasitised and unparasitised mealybugs (except for mealybugs parasitised by A. pseudococci).     

西花蓟马、二斑叶螨与黄瓜新小绥螨的相互关系研究

西花蓟马Frankliniella occidentalis（Pergande）和二斑叶螨Tetranychus urticae Koch是温室花卉与蔬菜上的重要害虫（螨）。植物常被两者同时危害。黄瓜新小绥螨Amblyseius cucumeris（Oudemans）是世界上广泛应用的温室蓟马的生物防治物,有时也被用来防治二斑叶螨。本研究中,在人工气候室盆栽条件下利用黄瓜新小绥螨防治西花蓟马和/或二斑叶螨。结果显示,当每豆株上接入10或20头二斑叶螨时,按照1∶4的益害比释放黄瓜新小绥螨可有效控制二斑叶螨。同样密度比的情况下,5和10头黄瓜新小绥螨的释放量可显著控制西花蓟马的接入量。二斑叶螨密度的增加没有显著影响到黄瓜新小绥螨对西花蓟马的控制作用。西花蓟马可捕食黄瓜新小绥螨的卵,日捕食量达1.2粒。本文对利用黄瓜新小绥螨防治温室中西花蓟马进行了讨论。     

捕食螨在我国农林害螨生物防治中的应用

捕食螨是农林生产中极具价值的生防作用物。文章对捕食螨在我国农林害螨生物防治中的应用作一综述,内容包括:与释放应用相关的研究(引进与风险评估,饲养、贮存与运输,食性与释放,捕食与繁殖,定殖与扩散,外界影响因子)、几种主要捕食螨(智利小植绥螨Phytoseiulus persimilis、西方盲走螨Typhlodromus occidentalis、伪钝绥螨Amblyseius fallacis、胡瓜钝绥螨A.cucumeris)的应用、释放应用前景与展望等,旨在提高我国的捕食螨研究与应用水平。     

Intraguild predation and interference by the mealybug predator Cryptolaemus montrouzieri on the parasitoid Leptomastix dactylopii

The compatibility of the encyrtid parasitoid Leptomastix dactylopii with the coccinellid beetle Cryptolaemus montrouzieri against the citrus mealybug, Planococcus citri, is determined by the extent of intraguild predation and interference by the predator. We tested the preference of the adults and fourth-instar larvae of C. montrouzieri for healthy mealybugs and parasitized mealybugs harboring 1-, 4-, 7- and 14-day-old parasitoid larvae. The experiments were conducted in no-choice (only unparasitized mealybugs or parasitized mealybugs of one parasitoid age were offered at one time) and choice (unparasitized and parasitized mealybugs of a specific age were offered simultaneously) tests. Both the adults and larvae of C. montrouzieri fed on unparasitized and parasitized mealybugs but strongly discriminated against the hardened mummies (14 days old). We also investigated the influence of the presence of C. montrouzieri to the foraging effectiveness of L. dactylopii. The level of parasitism by L. dactylopii was reduced from about 13 to 6% when the number of the C. montrouzieri was increased from zero to four. We recommended that the releases of C. montrouzieri should be conducted 14 days after the releases of L. dactylopii to reduce intraguild predation on the parasitized mealybugs and to avoid interference with the foraging parasitoids.     

Potential predation of the exotic Amblyseius swirskii on Euseius concordis (Acari: Phytoseiidae), a predatory mite commonly found in Brazil

Intra/interspecific predation by A. swirskii.

Both Benin and Netherlands populations of Amblyseius swirskii engaged in cannibalism, and in predation on Euseius concordis larvae. Provision of pollen decreased cannibalism considerably, but had a smaller effect on predation on E. concordis. Potential effect of the eventual introduction of A. swirskii for control of Bemisia tabaci in Brazil is discussed.     

Cannibalism and interspecific predation in the phytoseiid mites Phytoseiulus persimilis and Neoseiulus californicus: predation rates and effects on reproduction and juvenile development

We examined intra- and interspecific predation of adult females and immature stages of the generalist Neoseiulus californicus and the specialist Phytoseiulus persimilis. Adult females and immatures of both predators exhibited higher predation rates on larvae than on eggs and protonymphs. N. californicus fed more inter- than intraspecifically. Predation on P. persimilis by N. californicus was more severe than vice versa. P. persimilis had higher predation rates on conspecifics than heterospecifics and was more prone to cannibalism than N. californicus. When provided with phytoseiid prey, P. persimilis suffered higher mortality than N. californicus. When held without food, adult females and protonymphs of N. californicus survived longer than the corresponding stages of P. persimilis. N. californicus females were able to sustain oviposition when preying upon P. persimilis, whereas cannibalizing females did not lay eggs. Females of P. persimilis were not able to sustain oviposition, irrespective of con- or heterospecific prey. Immatures of both predators were able to reach adulthood when provided with either con- or heterospecifics. Juvenile development of N. californicus was shorter with heterospecific vs. conspecific larvae; mortality of P. persimilis immatures was less when feeding on conspecific vs. heterospecific larvae. Different behavioral pattern in intra- and interspecific predation are discussed in regard to their feeding types (generalist vs. specialist).     

Effect of Amblyseius cucumeris and Amblyseius barkeri as biological control agents of thrips tabaci on glasshouse cucumbers

Biological control of Thrips tabaci by the phytoseiid mites Amblyseius cucumeris and Amblyseius barkeri was investigated on glasshouse parthenocarpic cucumbers. The mite species were used in combination and singly. Successful thrips control was obtained with A. cucumeris alone, whereas control was not reliable with A. barkeri alone nor with the combination of A. cucumeris and A. barkeri. The establishment period was long for both phytoseiid species. At the beginning of the trial, when thrips were absent or very low in numbers, only A. cucumeris was found on the leaves. Mite populations did not increase until the number of thrips were ca. two and five per leaf for A. cucumeris and A. barkeri, respectively. A. cucumeris seemed to show a better numerical response to T. tabaci than A. barkeri. At the end of the trial (three months after the last introduction of mites) only A. barkeri was found in the combination plot, indicating that A. cucumeris is displaced by A. barkeri in situations of interspecific competition between the two species on glasshouse parthenocarpic cucumbers.     

Nutritional benefits of intraguild predation and cannibalism among generalist and specialist phytoseiid mites

1. Intraguild predation and cannibalism are common among predaceous phytoseiid mites (Acari, Phytoseiidae) but the nutritional benefits gained by these processes are poorly understood. 2. The study reported here addressed the questions of whether cannibalism and intraguild predation provide different nutritional benefits and whether the ability to utilise cannibalism and intraguild predation is linked to the diet specialisation of phytoseiid mites. Specialists tested were Phytoseiulus macropilis, Galendromus occidentalis, and Neoseiulus longispinosus; generalists tested were Amblyseius andersoni, Neoseiulus cucumeris, and Neoseiulus fallacis. 3. All generalists and the specialist P. macropilis were able to complete juvenile development with both con‐ and hetero‐specific prey. Juvenile development of generalists was shorter with heterospecific prey than with conspecific prey, whereas development of the specialist P. macropilis did not differ between prey types. Only a few N. longispinosus and G. occidentalis, both specialists, reached adulthood by cannibalism but none reached adulthood by intraguild predation. 4. All generalists were able to sustain oviposition by intraguild predation. Neoseiulus cucumeris and A. andersoni laid more eggs with heterospecific prey than with conspecific prey, whereas N. fallacis had similar oviposition rates with both prey types. No specialist sustained oviposition by intraguild predation or cannibalism. 5. Overall, generalists gained equal or more nutritional benefits by intraguild predation than by cannibalism and were able to utilise phytoseiid intraguild prey as an alternative food source. Specialists gained equal or more nutritional benefits from cannibalism than from intraguild predation. For specialists, con‐ and hetero‐specific phytoseiids may be considered only a supplemental food.     

Intraguild predation and cannibalism among Dicyphini: Dicyphus cerastii vs. two commercialized species

Dicyphine mirids are one of the most important groups of predators on tomato. In the Mediterranean region, several species in the genera Dicyphus, Macrolophus, and Nesidiocoris (Hemiptera: Miridae, Bryocorinae, Dicyphini) colonize protected horticultural crops. In Portugal, Nesidiocoris tenuis (Reuter) is increasingly abundant in the mirid species complex of tomato crops and appears to be displacing the native Dicyphus cerastii Wagner. In order to know whether intraguild predation (IGP) can explain the decreasing abundance of D. cerastii, we evaluated predatory interactions between adult females and first instars of D. cerastii vs. N. tenuis but also D. cerastii vs. Macrolophus pygmaeus (Rambur), as this species is also naturally present in horticultural crops in Portugal. Cannibalistic interactions were also tested for the same three species. All experiments were performed under laboratory conditions, in Petri dish arenas, in the presence or absence of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs as alternative prey. Predation on both heterospecific and conspecific nymphs occurred only in the absence of alternative food. Intraguild predation was mutual and symmetrical between D. cerastii and M. pygmaeus. However, IGP was asymmetrical between D. cerastii and N. tenuis, favouring the first. Cannibalism was not significantly different among these mirid species. Our results show that D. cerastii has a greater capacity to feed on intraguild prey than N. tenuis. Therefore, IGP on small nymphs does not explain the abundance shift between D. cerastii and N. tenuis.     

巴氏新小绥螨对同一栖息地枸杞瘿螨的捕食功能反应

枸杞瘿螨Aceria pallida Keifer（Acari: Eriophyoidae）是枸杞上为害最严重的有害生物之一。近期在内蒙古地区发现植绥螨巴氏新小绥螨Neoseiulus barkeri Hughes（Acari: Phytoseiidae）与枸杞瘿螨可同时发生在野生枸杞上。为评价巴氏新小绥螨对枸杞瘿螨的捕食潜力,本研究在室内25±1℃、RH 65%±10%、16 L∶8 D的条件下,研究了巴氏新小绥螨对不同密度枸杞瘿螨成螨（30、50、70、90、110、130、150、170头）的捕食功能反应及搜寻效应。结果表明,巴氏新小绥螨的雌、雄成螨对枸杞瘿螨成螨的捕食功能反应均为Holling-II型,即巴氏新小绥螨雌、雄成螨的捕食量随着猎物密度的增加而增加,一直到猎物密度较高时趋于稳定;而巴氏新小绥螨雌、雄成螨的搜寻效应随着猎物密度的增加而降低。巴氏新小绥螨雌成螨对相同密度下的枸杞瘿螨成螨的捕食量均高于雄成螨,而且雌成螨的搜寻效应也强于雄成螨。巴氏新小绥螨雌成螨的攻击率（α=4.4121）高于雄成螨（α=2.4403）,而雌成螨的处理时间（Th =0.0094 d）短于雄成螨（Th=0.0196 d）;雌、雄成螨的理论最大日捕食量（T/Th）分别为106.61头和51.02头。研究结果显示巴氏新小绥螨对枸杞瘿螨有较好的捕食潜力,性别对巴氏新小绥螨捕食枸杞瘿螨的功能反应有显著影响。     

Interspecific competition and predation between immature Amblyseius fallacis,Amblyseius andersoni,Typhlodromus occidentalis and Typhlodromus pyri (Acari: Phytoseiidae)

Interspecific competition and predation in immature Amblyseius fallacis (Garman), Amblyseius andersoni Chant, Typhlodromus occidentalis (Nesbitt) and Typhlodromus pyri Scheuten were examined in small cages at three egg densities (0, 20 and 80) of two-spotted spider mite, Tetranychus urticae Koch, in the laboratory at 25±1°C,80% RH and 16L: 8D photoperiod. For the six possible between-species comparisons, the large polyphagous A. andersoni always outcompeted the other three predator species, which were either smaller and/or less polyphagous; the small oligophagous T. occidentalis was always eliminated by the other three predator species, which were either larger and/or more polyphagous. The small and polyphagous T. pyri tied with the large and oligophagous A. fallacis. The outcome of the interaction was generally similar at the three prey densities except in (1) the A. fallacis-A. andersoni system where the advantage of A. andersoni over A. fallacis was reduced when 20 or 80 eggs per cage were present at the start of the interaction and (2) the A. fallacis-T. occidentalis system where the advantage of A. fallacis over T. occidentalis increased with prey density. This study indicates that predator size, predator degree of polyphagy and prey density can affect the competitiveness of immature phytoseiids.     

The enemy of my enemy is my friend: intraguild predation between invaders and natives facilitates coexistence with shared invasive prey

Understanding and predicting the outcomes of biological invasions is challenging where multiple invader and native species interact. We hypothesize that antagonistic interactions between invaders and natives could divert their impact on subsequent invasive species, thus facilitating coexistence. From field data, we found that, when existing together in freshwater sites, the native amphipod Gammarus duebeni celticus and a previous invader G. pulex appear to facilitate the establishment of a second invader, their shared prey Crangonyx pseudogracilis. Indeed, the latter species was rarely found at sites where each Gammarus species was present on its own. Experiments indicated that this may be the result of G. d. celticus and G. pulex engaging in more intraguild predation (IGP) than cannibalism; when the ‘enemy’ of either Gammarus species was present, that is, the other Gammarus species, C. pseudogracilis significantly more often escaped predation. Thus, the presence of mutual enemies and the stronger inter- than intraspecific interactions they engage in can facilitate other invaders. With some invasive species such as C. pseudogracilis having no known detrimental effects on native species, and indeed having some positive ecological effects, we also conclude that some invasions could promote biodiversity and ecosystem functioning.