乳突寄螨雌螨描述(蜱螨亚纲: 革螨股: 寄螨科)

乳突寄螨 Parasitus mammillatus ( Berlese,1 90 4 )雌螨 ,在所查到的文献中 ,仅记载有生殖区、头盖和螯钳的形状 [1 ,2 ] ,无其它描述。国内根据丹东标本曾描述该螨雄螨和后若螨 [3] 。本文根据朝鲜标本详细描述其雌螨。文中测量单位为 μm,括号内为测量均值。图 1- 7　乳突寄螨 Parasitus mammillatus (Berlese)1.背面 ;2 .腹面 ;3.头盖 ;4 .螯钳 ;5 .颚角 ;6 .须肢 ;7.跗节 乳突寄螨 Parasitus mammillatus ( Berlese,1 90 4 )雌螨 (图 1 - 7)体黄色 ,卵圆形 ,长 71 2 - 793( 758) ,宽 4 0 2 - 483( 4 50 )。背板覆盖整个背面 ,前背…     

克瓦厚厉螨雄螨及后若螨描述(蜱螨亚纲:革螨股:厚厉螨科)

克瓦厚厉螨（Pachylaelaps kievati Davydova,1971）,在所查到的献中仅描述了雌螨（KoponeBa,1977）,本描述其雄螨及后若螨。     

单角新革螨雌雄螨描述(蜱螨亚纲:革螨股:寄螨科)

单角新革螨 Neogamasus unicornutus ( Ewing,1 90 9)同物异名为岛屿新革螨 Neogamasusislandicus( Sellnick,1 94 0 ) ,其后若螨 [1 ]、前若螨及幼螨 [2 ]已有较详细描述 ,但雌螨和雄螨在所查到的文献中只记载有个别特征 ,没有完整描述 [1 ,3- 6] 。本文根据采自集安的标本 ,描述其雌螨和雄螨。文中测量单位为 μm,括号内为测量均值。单角新革螨 Neogamasusunicornutus(Ewing,190 9)雌螨 (图 1 - 7)体黄色 ,卵圆形 ,长 6 78- 70 1 ( 6 89) ,宽 36 8- 41 4 ( 394 )。背板几乎覆盖整个背面 ,后部留狭窄裸露区。前背板长 345- 356 ( 349) ,…     

东北常革螨后若螨描述（蜱螨亚纲：寄螨科）

东北常革螨过去仅描述雌螨和雄螨，本描述后若螨。中测量单位为μm。     

峰革赛螨幼若螨描述（蜱螨亚纲：革螨股：胭螨科）

在所查到的献中，峰革赛螨Gamasellus montanus(Willmann，1936)仅描述了雌和雄螨(BpereToBa和Щep5aK，1977)，本描述其后若螨、前若螨和幼螨。中测量单位为μm，括号内为测量均值。     

萎缩巨螯螨雄螨与后若螨描述及雌螨特征补充(蜱螨亚纲:革螨股:巨螯螨科)

萎缩巨螯螨 Macrocheles reductus Petrova,1 96 6在所查到的文献中仅见雌螨描述(Брегетова,1 977)。本文描述其雄螨与后若螨 ,并补充雌螨特征。萎缩巨螯螨 Macrochelesreductus Petrova,1966雌螨形态补充描述 (图 1 - 2 )　形态与原描述所绘图 ( Брегетова,1 977)比较 ,中国标本胸板后缘凹陷较深 ;腹肛板较狭长 ,长宽为 2 53- 31 0× 1 1 5- 1 4 9(平均 2 81× 1 30 )μm,呈有变异。图 1　萎缩巨螯螨 Macrocheles reductus Petrova♀1.胸板 ;2 .腹肛板变异雄螨 (图 1 - 4)　体黄色 ,椭圆形。背板 885× 575μm,后部明…     

力氏广厉螨雄螨与后若螨描述(蜱螨亚纲:革螨股:厉螨科)

描述力氏广厉螨Cosmolaelaps hrdyi Sam（s）iň（a）k,1961 雄螨和后若螨.     

孟氏新革螨前若螨描述（蜱螨亚纲：革螨股 寄螨科）

孟氏新革螨Neogamasus mengyangchunae(Ma)过去已描述雌、雄和后若螨,今描述其前若螨。     

乌苏里土厉螨和维内土厉螨若螨描述(蜱螨亚纲:革螨股:厉螨科)

乌苏里土厉螨 Ololaelaps ussuriensis Bregetova et Koroleva,1 96 4和维内土厉螨 Ololaelapsveneta( Berlese,1 90 3)在所查到的文献中仅描述了雌螨和雄螨[1 ,2 ] ,本文描述其若螨。文中测量单位为μm,括号内为测量均值。1乌苏里土厉螨 Ololaelapsussuriensis Bregetova et Koroleva,1964　　形态描述　后若螨 (图 1 - 3)体黄色 ,近圆形 ,长宽 51 7- 6 55× 4 0 2 - 540 ( 577× 4 6 6 )。背板覆盖整个或几乎整个背面 ,有深而狭的侧切口。背板前区有毛 1 9对 ,后区 1 4对 ,均细小 ,另有若干对小圆孔。胸板长 2 30 - 2 6 4( 2 37) ,St2…     

拟长毛钝绥螨与硃砂叶螨相互作用的实验研究——干扰作用和搜寻效率

在猎物卵不同密度下,拟长毛钝绥螨(Amblyseius pseudolongispinosus)随其种群密度的增加(不超过10头/叶片),个体之间不存在干扰作用;捕食螨的搜寻活动和产卵分布对猎物分布的变动有一定的时滞性;聚集行为往往是由于某些生境中猎物被消耗殆尽后引起的,这与捕食螨在猎物卵不同密度下的扩散作用和干扰作用较弱有关。     

A functional response model of a predator population foraging in a patchy habitat

1. Functional response models (e.g. Holling's disc equation) that do not take the spatial distributions of prey and predators into account are likely to produce biased estimates of predation rates. 2. To investigate the consequences of ignoring prey distribution and predator aggregation, a general analytical model of a predator population occupying a patchy environment with a single species of prey is developed. 3. The model includes the density and the spatial distribution of the prey population, the aggregative response of the predators and their mutual interference. 4. The model provides explicit solutions to a number of scenarios that can be independently combined: the prey has an even, random or clumped distribution, and the predators show a convex, sigmoid, linear or no aggregative response. 5. The model is parameterized with data from an acarine predator-prey system consisting of Phytoseiulus persimis and Tetranychus urticae inhabiting greenhouse cucumbers. 6. The model fits empirical data quite well and much better than if prey and predators were assumed to be evenly distributed among patches, or if the predators were distributed independently of the prey. 7. The analyses show that if the predators do not show an aggregative response it will always be an advantage to the prey to adopt a patchy distribution. On the other hand, if the predators are capable of responding to the distribution of prey, then it will be an advantage to the prey to be evenly distributed when its density is low and switch to a more patchy distribution when its density increases. The effect of mutual interference is negligible unless predator density is very high. 8. The model shows that prey patchiness and predator aggregation in combination can change the functional response at the population level from type II to type III, indicating that these factors may contribute to stabilization of predator-prey dynamics.     

Gregariousness versus solitude: another look at parasite faunal richness in Canadian freshwater fishes

Summary The expectation of the ideal free distribution is a functional response in which intake is constant in all sites and, if interference is low, an aggregative response in which all individuals cluster in the high prey density sites. Incorporating individual differences in competitive ability results in a functional response in which intake increases with prey density and an aggregative response in which individuals are more evenly distributed.     

The advantage of alternative tactics of prey and predators depends on the spatial pattern of prey and social interactions among predators

Individual variation in behavioral strategies is ubiquitous in nature. Yet, explaining how this variation is being maintained remains a challenging task. We use a spatially-explicit individual-based simulation model to evaluate the extent to which the efficiency of an alternative spacing tactic of prey and an alternative search tactic of predators are influenced by the spatial pattern of prey, social interactions among predators (i.e., interference and information sharing) and predator density. In response to predation risk, prey individuals can either spread out or aggregate. We demonstrate that if prey is extremely clumped, spreading out may help when predators share information regarding prey locations and when predators shift to area-restricted search following an encounter with prey. However, dispersion is counter-selected when predators interact by interference, especially under high predator density. When predators search for more randomly distributed prey, interference and information sharing similarly affect the relative advantage of spreading out. Under a clumped prey spatial pattern, predators benefit from shifting their search tactic to an area-restricted search following an encounter with prey. This advantage is moderated as predator density increases and when predators interact either by interference or information sharing. Under a more random prey pattern, information sharing may deteriorate the inferior search tactic even more, compared to interference or no interaction among predators. Our simulation clarifies how interactions among searching predators may affect aggregation behavior of prey, the relative success of alternative search tactics and their potential to invade established populations using some other search or spacing tactics.     

Distribution and feeding behaviour of field populations of the water cricket Velio, caprai (Hemiptera)

1. The distribution of individuals, prey capture success and prey choice were studied in a water cricket (Velia caprai) population in southern Ireland. Groups of different sizes were observed in the field during the summer and all potential prey animals entering the groups were counted. Surface drift samples were collected to assess the proportion of profitable prey items. 2. Two types of Velia groups were observed: mixed groups (adults and juvenile instars 4 and 5) and juvenile groups (instars 1–3), A greater proportion of the available prey was captured by the mixed groups. 3. Individuals in large groups had a lower capture rate than individuals in small groups. 4. No differences in capture rates could be found between males, females and juveniles, but differences in prey choice were apparent. Females captured more large prey than expected. 5. Water cricket distribution in the stream did not follow the ‘ideal free’ model; too few individuals were found at the most profitable sites. Food might not be the limiting factor during summer, and other factors such as intraspecific interference and predator avoidance could be more important.     

Interference coloration as an anti-predator defence

Interference coloration, in which the perceived colour varies predictably with the angle of illumination or observation, is extremely widespread across animal groups. However, despite considerable advances in our understanding of the mechanistic basis of interference coloration in animals, we still have a poor understanding of its function. Here, I show, using avian predators hunting dynamic virtual prey, that the presence of interference coloration can significantly reduce a predator''s attack success. Predators required more pecks to successfully catch interference-coloured prey compared with otherwise identical prey items that lacked interference coloration, and attacks against prey with interference colours were less accurate, suggesting that changes in colour or brightness caused by prey movement hindered a predator''s ability to pinpoint their exact location. The pronounced anti-predator benefits of interference coloration may explain why it has evolved independently so many times.     

Predator search pattern and the strength of interference through prey depression

We develop a model of predators foraging within a single patch,on prey that become temporarily immune to predation (depressed)after detecting a predator. Interference through prey depressionoccurs because the proportion of vulnerable prey (and henceintake rate) decreases as predator density increases. Predatorsin our model are not forced to move randomly within the patch,as is the case in other similar models, but can avoid areasof depressed prey and so preferentially forage over vulnerableprey. We compare the extent to which different avoidance rules(e.g., move more quickly over depressed prey or turn if approachingdepressed prey) influence the amount of time spent foragingover depressed and vulnerable prey, and how this influencesthe strength of interference. Although based on a different mechanism, our model produces two similar general predictionsto interference models based on direct interactions betweenpredators: the strength of interference increases with (1)increased competitor density and (2) decreased prey encounterrate. This suggests that there are underlying similarities in the nature of interference even when it arises through differentprocesses. Not surprisingly, avoidance of depressed prey cansubstantially reduce the strength of interference comparedwith random foraging. However, we identify the region of themodel's parameter space in which this reduction is particularlylarge and show that the only system for which suitable dataare available, redshank Tringa totanus feeding on Corophium volutator, falls within this region. The model shows that, byadjusting its search path to avoid areas of depressed prey,a predator can substantially reduce the amount of the interferenceit experiences and that this applies over a wide range of parameterspace, including the region occupied by a real system. Thissuggests that behavior-based interference models should consider predator search pattern if they are to accurately predict thestrength of the interference.     

Animal foods in the diets of wild chimpanzees (Pan troglodytes): Why cross-cultural variation?

The common chimpanzee (Pan troglodytes) in nature is an omnivore, i.e. it eats animals as well as plants. Six long-term field studies reveal differences in diet amongst populations of chimpanzees in east, central and west Africa. Specific comparisons can be made for social insect (ants, bees, termites) and mammalian (primates, ungulates) prey. Most of the differences can be explained in terms of environmental influences: presence or absence of prey species, abundance and distribution of prey, range of potential prey secies, competing predators, characteristics of habitat, human interference. However, other differences appear to reflect true social customs, independent of the bio-physical environment, and therefore can be termed cross-cultural.     

Predator-prey responses in an acarine system

Summary This study examines the responses of the predatory mite,Phytoseiulus persimilis, to the density and distribution of its prey,Tetranychus urticae. It is divided into three parts. Firstly, the functional responses of protonymph, deutonymph and adult females towards different prey stages are displayed. The great majority of the responses are of the type II form, and the variations in the values of attack ratea′ and handling timeT _h are discussed. Experiments are then described in which individual protonymph, deutonymph and adult female predators are presented with varying ratios of two prey age-classes (eggs and deutonymphs, and larvae and deutonymphs). Any observed preference for one of the prey stages is discussed in relation to the predicted preference on the basis of the separate functional response experiments. Finally, the response of different densities of adult female predators to a non-random distribution of deutonymph prey on bean leaflets is examined. The predators show a clear tendency to aggregate on the leaflets of high prey density, counteracted to some extent by interference increasing the probability of dispersal to other leaflets.     

The Effects of Prey Patchiness, Predator Aggregation, and Mutual Interference on the Functional Response of Phytoseiulus persimilis Feeding on Tetranychus urticae (Acari: Phytoseiidae, Tetranychidae)

The spatial distributions of two-spotted spider mites Tetranychus urticae and their natural enemy, the phytoseiid predator Phytoseiulus persimilis, were studied on six full-grown cucumber plants. Both mite species were very patchily distributed and P. persimilis tended to aggregate on leaves with abundant prey. The effects of non-homogenous distributions and degree of spatial overlap between prey and predators on the per capita predation rate were studied by means of a stage-specific predation model that averages the predation rates over all the local populations inhabiting the individual leaves. The empirical predation rates were compared with predictions assuming random predator search and/or an even distribution of prey. The analysis clearly shows that the ability of the predators to search non-randomly increases their predation rate. On the other hand, the prey may gain if it adopts a more even distribution when its density is low and a more patchy distribution when density increases. Mutual interference between searching predators reduces the predation rate, but the effect is negligible. The stage-specific functional response model was compared with two simpler models without explicit stage structure. Both unstructured models yielded predictions that were quite similar to those of the stage-structured model.