Nutrient-specific foraging in invertebrate predators

Many herbivores and omnivores adjust their food selection behavior to regulate the intake of multiple nutrients. Carnivores, however, are generally assumed to optimize the rate of prey capture rather than select prey according to nutrient composition. We showed experimentally that invertebrate predators can forage selectively for protein and lipids to redress specific nutritional imbalances. This selection can take place at different stages of prey handling: The predator may select among foods of different nutritional composition, eat more of a prey if it is rich in nutrients that the predator is deficient in, or extract specific nutrients from a single prey item.     

荔枝蒂蛀虫雄蛾触角感受器的扫描电镜观察

应用扫描电镜对荔枝蒂蛀虫雄蛾触角感受器的超微结构进行观察.结果表明:荔枝蒂蛀虫雄蛾触角上主要分布5种感受器,分别是毛形感受器、刺形感受器、腔锥感受器、锥形感受器、鳞形感受器.对各种感受器的形态特点进行描述,其中毛形感受器数量最多.     

Aggressive chemical mimicry by a bolas spider

Mature female Mastophora sp. spiders attract prey with a volatile substance which apparently mimics the female sex attractant pheromone of the fall armyworm Spodoptera frugiperda (Lepidoptera). The rate of prey capture is similar to that of a conventional orb weaver of comparable body size.     

桃小食心虫触角感受器扫描电镜观察

【目的】研究桃小食心虫（Carposina niponensis Walsingham）触角的外部形态及其感受器的种类和分布,为了解桃小食心虫的寄主选择和交配选择机理奠定基础。【方法】以桃小食心虫成虫雌雄蛾为试材,应用扫描电子显微镜对其触角的外部形态及触角感受器进行观察。【结果】桃小食心虫成虫触角感受器有毛形感器（Ⅰ和Ⅱ）、刺形感器、畸形刺感器、芽孢感器、锥形感器（Ⅰ和Ⅱ）、腔锥感器、栓锥感器、耳形感器（Ⅰ、Ⅱ和Ⅲ）、鳞形感器和Bhm氏鬃毛,其中芽孢感器、畸形刺感器、耳形感器Ⅱ和Ⅲ仅在雌蛾触角中发现。【结论】桃小食心虫的触角感受器种类丰富,雌蛾触角特有的4类感受器可能与其产卵和寄主选择等行为有关。     

美国白蛾触角感器超微结构

为研究美国白蛾(Hyphantria cunea)触角感器与其嗅觉感受机制的关系,借助扫描电镜观察了其触角感器类型及其分布。结果显示:美国白蛾雌蛾触角为锯齿状,雄蛾触角为双栉齿状,也称羽毛状;在雌雄触角上共发现10种类型感器,即长毛形感器Ⅰ(ST-Ⅰ)、短毛形感器Ⅱ(ST-Ⅱ)、刺形感器(SCH)、锥形感器(SB)、栓锥形感器(SST)、具缘毛腔锥形感器Ⅰ(SCO-Ⅰ)、无缘毛腔锥形感器Ⅱ(SCO-Ⅱ)、鳞形感器(SSQ)、B hm氏鬃毛(BB),以及一种新型感器——舌形感器(SL)。毛形感器数量最多,且雄蛾多于雌蛾。雌雄蛾同类感器中除SCO-I雌雄差异不显著外,其余感器类型长度雌雄均差异显著,其中,雌蛾SST及SCO-Ⅱ长度均显著大于雄蛾,ST-Ⅰ、ST-Ⅱ、SCH、SB及SSQ长度均为雄蛾显著大于雌蛾。SL仅分布于雄蛾羽状分支腹面,SSQ位于雌雄触角纵轴及分支背面,BB位于雌雄触角柄节两侧,其余感器均分布于雌雄触角腹面。     

Influence of Siphonophore Behavior upon Their Natural Diets: Evidence for Aggressive Mimicry

Collection by divers permitted determination of the natural diets of siphonophore species within II genera. Siphonophores that swim rapidly to spread their tentacles capture small prey, whereas those that swim very weakly capture much larger prey. Nematocyst batteries of two species of weak swimmers closely resemble copepods and fish larvae. Morphology, behavior, and diet suggest that these two species attract large prey by mimicking other zooplankton.     

Faking giants: the evolution of high prey clearance rates in jellyfishes

Jellyfishes have functionally replaced several overexploited commercial stocks of planktivorous fishes. This is paradoxical, because they use a primitive prey capture mechanism requiring direct contact with the prey, whereas fishes use more efficient visual detection. We have compiled published data to show that, in spite of their primitive life-style, jellyfishes exhibit similar instantaneous prey clearance and respiration rates as their fish competitors and similar potential for growth and reproduction. To achieve this production, they have evolved large, water-laden bodies that increase prey contact rates. Although larger bodies are less efficient for swimming, optimization analysis reveals that large collectors are advantageous if they move through the water sufficiently slowly.     

友恩蚜小蜂雌蜂触角、口器感觉系统电镜扫描观察

电镜扫描观察表明:友恩蚜小蜂雌蜂触角具有毛形感觉器、板形感觉器、钟形感觉器、指形感觉器和B hm氏鬃毛等5种感觉器.上颚发达,左、右上颚各具3根毛形感觉器;下颚须和下唇须各1节,在末端和近末端1/3处,分别具1根刺形感觉器.同时还探讨了各种感觉器的功能.     

Antennal mechanosensors mediate flight control in moths

Flying insects have evolved sophisticated sensory capabilities to achieve rapid course control during aerial maneuvers. Among two-winged insects such as houseflies and their relatives, the hind wings are modified into club-shaped, mechanosensory halteres, which detect Coriolis forces and thereby mediate flight stability during maneuvers. Here, we show that mechanosensory input from the antennae serves a similar role during flight in hawk moths, which are four-winged insects. The antennae of flying moths vibrate and experience Coriolis forces during aerial maneuvers. The antennal vibrations are transduced by individual units of Johnston's organs at the base of their antennae in a frequency range characteristic of the Coriolis input. Reduction of the mechanical input to Johnston's organs by removing the antennal flagellum of these moths severely disrupted their flight stability, but reattachment of the flagellum restored their flight control. The antennae thus play a crucial role in maintaining flight stability of moths.     

Variation in the social grouping tendency of a communal web-building spider

The orb web-building spider, Metepeira spinipes, from Mexico occurs solitarily and, more frequently, in aggregations of 5 to 150 or more individuals. Although communal, individuals maintain webs and retreats within the colony and capture their own prey. Group size and interindividual distance apparently vary in response to climate and availability of prey.     

烟蚜茧蜂触角的超微结构与冷藏对触角的影响

【目的】明确烟蚜茧蜂（Aphidius gifuensis）触角和触角感觉器的外部形态及低温冷藏对其触角的影响,为烟蚜茧蜂的有效利用提供依据。【方法】采用扫描电镜观察正常羽化的烟蚜茧蜂雌、雄蜂触角的超微结构,比较雌、雄蜂触角感觉器的差异。将处于老熟幼虫期的烟蚜茧蜂在4℃低温下分别冷藏7、14、21和28 d,冷藏后用乙醇对样品进行脱水处理,并在扫描电镜下观察低温冷藏对烟蚜茧蜂触角外部形态及触角感觉器的影响。【结果】烟蚜茧蜂雌、雄成蜂触角外部形态相似,均属于丝状触角。雄蜂触角平均长度略长于雌蜂,雌蜂触角多为17节,雄蜂触角多为19节。成蜂触角上共有6种类型的感觉器：毛形感觉器、刺形感觉器、板形感觉器、Böhm氏鬃毛、腔锥形乳突状感觉器和锥形感觉器。毛形感觉器I主要分布在触角鞭节上,是触角上分布最广、数量最多的感觉器。板形感器主要分部在鞭节上,雄蜂从第1鞭节开始出现,雌蜂从第2鞭节开始出现。腔锥形乳突状感觉器II只存在于雄蜂触角上。雌、雄蜂感觉器的数量存在差异,雌蜂的刺形感觉器I数量多于雄蜂,雄蜂的刺形感觉器II和板形感觉器的数量则多于雌蜂。低温处理14、21、28 d后,板形感觉器、腔锥形乳突状感觉器均表现畸形,且触角最后两节分节不明显,有愈合成一节的趋势。冷藏28 d后,54%雄性触角不能正常分节,由正常情况下的19节而愈合为18节;69%的雌性触角不能正常分节,由正常情况下的17节而愈合为16节。【结论】烟蚜茧蜂触角属于丝状触角,共有6种类型感觉器。雄蜂触角长于雌蜂,感觉器的分布特点相似。低温冷藏对烟蚜茧蜂某些触角感觉器形态及触角末两节分节有显著影响。为减少冷藏对烟蚜茧蜂的伤害,应尽量避免在蛹期以前的虫态低温保存蜂种,且应缩短冷藏时间。     

Effects of Various Degrees of Antennal Ablation on Mating and Oviposition Preferences of the Diamondback Moth,Plutella xylostella L.

Using scanning electron microscopy, we investigated the distribution of the trichoid, basiconic, and coeloconic sensilla on the antennae of the diamondback moth (DBM; Plutella xylostella). The trichoid sensilla were the most abundant sensory organ, and the male moth antennae host significantly more trichoid sensilla than female moth antennae. Conversely, basiconic and coeloconic sensilla were found more frequently on female than on male antennae. We performed experiments with various degrees of antennal ablation and demonstrated that DBM antennae played a key role in the control of mating and oviposition. We found that neither oviposition preference nor mating behaviors changed significantly when less than 1/4 of both antennae were removed. However, there was a significant behavioral change when the antennae were ablated by more than half. As the length of the antenna was shortened, the successful mating rate decreased and mating peak was delayed. An otherwise consistent host preference for oviposition was eliminated when both antennae were completely removed. Furthermore, we found that the number of trichoid sensilla was positively correlated with mating rate and oviposition preference. However, the numbers of basiconic and coeloconic sensilla were not correlated with mating rate and mating peak, but highly correlated with oviposition preference. Taken together, our results indicate that antennal sensory information plays a critical role in the mating and oviposition behaviors of this economically important pest.     

The Ecological Significance of Sexual Dimorphism in Size in the Lizard Anolis conspersus

Adult males of Anolis conspersus capture prey of significantly larger size and occupy perches of significantly greater diameter and height than do adult females; similarly, these three dimensions of the niche are significantly larger for adult females than for juveniles. Adult males on the average eat a smaller number of prey, and the range in size of prey is larger. The relationship between the average length of the prey and that of the predator is linear when the predator size is above 36 millimeters, but becomes asymptotic when it is below that value. Subadult males as long as adult females eat significantly larger food than do the latter, but only in the larger lizards is this correlated with a relatively larger head. Anolis conspersus selects prey from a wide range of taxa and shows no obvious intraspecific specialization not connected to differences in microhabitat and prey size. The efficiency of this system for solitary species is pointed out.     

韭菜迟眼蕈蚊触角感受器的类型、分布与内部结构

利用光学显微镜、扫描电镜和透射电镜对韭菜迟眼蕈蚊成虫触角感受器的细微结构进行了观察研究。根据感受器外部特征和内部结构,将触角感受器分5种类型,分别是毛形感器、锥形感器Ⅰ、锥形感器Ⅱ、机械感觉毛Ⅰ、机械感觉毛Ⅱ。这5种类型感受器分布在触角不同部位,毛形感器、锥形感器Ⅰ、锥形感器Ⅱ分布于鞭节,而机械感觉毛Ⅰ、机械感觉毛Ⅱ主要分布在柄节和梗节。对雌雄虫触角各种感受器数量比较发现,雄成虫毛形感器数量极显著(P<0.01)多于雌虫的,而雌虫锥形感器Ⅰ的数量极显著(P<0.01)多于雄虫的。     

Chemical impurity produces extra compound eyes and heads in crickets

A chemical impurity isolated from commercially purchased acridine causes cricket embryos to develop extra compound eyes, branched antennae, extra antennae, and extra heads. Purified acridine does not produce similar duplications of cricket heads or head structures nor do the substituted acridines proflavine, acriflavine, or acridine orange. A dose-response relation exists such that the number and severity of abnormalities increase with increasing concentration of the teratogen.     

Environmental and genetical contributions to class difference: a model experiment

Flies were divided into two groups on the basis of the number of their bristles, and raised under different environmental (temperature) conditions. In each generation, offspring of the two groups were retained in their group or transferred to the other group, depending on the number of their bristles. After nine generations it was found that the genetic component of the intergroup difference was 42 percent; the portion of the intragroup variance that was genetic phenomena.     

Cooperative Hunting Harris' Hawks (Parabuteo unicinctus)

Coordinated hunting by several individuals directed toward the capture and sharing of one Large prey animal has been documented convincingly only for a few mammalian carnivores. In New Mexico, Harris' hawks formed hunting parties of two to six individuals in the nonbreeding season. This behavior improved capture success and the average energy available per individual enabled hawks to dispatch prey larger than themselves. These patterns suggest that cooperation is important to understanding the evolution of complex social behavior in higher vertebrates and, specifically, that benefits derived from team hunting a key factor in the social living of Harris' hawks.     

Primate predation: interim report on the development of a tradition in a troop of olive baboons

A troop of olive baboons, Papio anubis, has developed systematic predation, which includes hunting and sharing of meat. Although meat-eating among nonhuman primates-baboons and chimpanzees especially-had been discovered in earlier field studies, systematic predation had been reported for chimpanzees and humans only. Starting as an adult male activity in the olive baboon troop, this tradition rapidly expanded to include capture and consumption of prey by adult females and juveniles of all ages and both sexes. Infants eat but have not been observed to capture prey.     

Photon-mediated hybridization of frenkel excitons in organic semiconductor microcavities

Coherent excitations of intricate assemblies of molecules play an important role in natural photosynthesis. Microcavities are wavelength-dimension artificial structures in which excitations can be made to couple through their mutual interactions with confined photon modes. Results for microcavities containing two spatially separated cyanine dyes are presented here, where simultaneous strong coupling of the excitations of the individual dyes to a single cavity mode leads to new eigenmodes, described as admixtures of all three states. These "hybrid" exciton-photon structures are of potential interest as model systems in which to study energy capture, storage, and transfer among coherently coupled molecular excitations.     

白蜡吉丁啮小蜂触角感觉器的扫描电镜观察

【目的】明确白蜡窄吉丁（Agrilus planipennis）的优势寄生性天敌—白蜡吉丁啮小蜂（Tetrastichus planipennisi）（膜翅目：姬小蜂科）触角及感觉器的外部形态特点。【方法】对白蜡吉丁啮小蜂触角的形态特征、感觉器的类型、形态、数量和分布特点进行扫描电镜观察,并对雌、雄蜂触角感觉器进行性别间差异比较。【结果】白蜡吉丁啮小蜂触角呈膝状,由柄节、梗节和鞭节组成,雌蜂鞭节有5亚节,雄蜂鞭节有4亚节。触角上着生有板形感器（Ⅰ型和Ⅱ型）、毛形感器（Ⅰ型、Ⅱ型和Ⅲ型）、指形感器、刺形感器、锥形乳头状感器和Böhm氏鬃毛,其中,板形感器Ⅰ型仅分布于雄蜂棒节,雌蜂未见分布,毛形感器Ⅱ型和Ⅲ型仅分布于雌蜂触角,雄蜂未见分布,雌蜂的毛形感器总数量显著多于雄蜂。【结论】白蜡吉丁啮小蜂触角呈膝状,共有6种类型感器,雌、雄蜂的感器类型、数量和分布规律存在差异,具有明显的性二型现象。