蛛蜂“童年”揭秘

序幕:杀手七月中的周末,我带着相机闲逛到公园的小树林里,看到不远处突然有东西晃动,第六感告诉我,有镜头了。三步变两步赶紧过去,一看,原来是一只黄毛泥蜂撞在树间的金黄色巨大蜘蛛网上,黄毛泥蜂被粘住,拼命挣扎想逃跑,就在此时,一只五色斑     

蛛蜂“童年”揭秘

序幕：杀手 七月中的周末,我带着相机闲逛到公园的小树林里,看到不远处突然有东西晃动,第六感告诉我,有镜头了。三步变两步赶紧过去,一看,原来是一只黄毛泥蜂撞在树间的金黄色巨大蜘蛛网上,黄毛泥蜂被粘住,拼命挣扎想逃跑,就在此时,     

中国蛛蜂科十新记录种

记述采自中国河北省小五台山、宁夏同族自治区六盘山的蛛蜂科 Pompilidae 2亚科(Pepsinae,Pompilinae)、5 属(Agenioideus,Arachnospila,Cryptocheilus,Evagetes,Priocnemis)、10中国新记录种.研究标本分别保存在河北大学和云南农业大学昆虫...     

狼蛛,蟹蛛和跳蛛

狼蛛、蟹蛛和跳蛛分别是蜘蛛目中三个科的蜘蛛的通称。这三类蜘蛛包括了我们日常见到的游猎型蜘蛛的大部分种类,它们在帮助人类消灭害虫中所起作用也较大,所以作为动物学教学中的例子加以介绍。 (一)狼蛛狼蛛在地面或植物上疾驰,凶狠如狼,故名。体长3-25毫米,但多数种类在5-8毫米间。体色多黄褐色,不鲜艳。8眼,排成三列。前列4个小眼,中、后两列各2个眼,较大;后列两眼的间距稍大于中列两眼的间距(图1左)。卵袋扁球形,由两片半圆形丝膜缝合而成。卵袋挂在母蛛腹部后端的纺器上,由母蛛随身携带。幼蛛孵出后不分散,而是爬伏在母蛛腹部     

奎孔蛛（跳蛛科）雌蛛记述

本文记述奎孔蛛的雌性和雄性鉴别特征。雌蛛最初记述于越南,雌蛛系新发现。文内附以雄蛛左触肢的腹面观和侧面观,其中侧面观的角度与原定名人的附图的角度不同,以供读者参考。本种在我国系新记录,产于湖南和云南两省,其实际分布范围尚待进一步调查。     

西双版纳布朗山不同演替阶段植被的蛛蜂物种多样性研究

为揭示西双版纳布朗山植被恢复过程中处于不同演替阶段的蛛蜂物种多样性及其群落特征与植被恢复程度的关系,并对蛛蜂作为生态环境指示物的作用进行初步探讨,本研究在布朗山天籽生物多样性保护区内采用马氏网、黄盘等诱集法系统调查研究了草丛、稀树草丛、次生林、天然林4类逐步演替生境中的蛛蜂物种多样性及群落特征.共采集到蛛蜂个体2584...     

黄褐新园蛛和茶色新园蛛幼蛛各龄期的比较

黄褐新园蛛(Neoscon,doenitzi)和茶色新园蛛(N.theisi)为我国农田常见害虫天敌。其幼蛛特征尚未见报道。鉴于在调查和统计种群数量时常易混淆。为此将两种蜘蛛通过室内饲养获得各龄期标本,进行描述。其各部位的量度统一以蜕皮后三天的幼蛛进行测量,比较如下:一龄幼蛛均在卵囊内。体淡黄色。附肢半透明状。头胸部的放射沟及颈沟均不显。眼列较为相似。但茶色新园蛛各眼显著大且黑于黄褐新园蛛。身体及附肢上具短毛。黄褐新园蛛腹部较茶色新园蛛圆。茶色新园蛛腹部背面隐约可见淡黄色的斑块。二龄幼蛛两种园蛛腹背均具淡黄色斑块,但黄褐新园…     

视觉能触发沟渠豹蛛雄蛛对雌蛛的求偶行为

以沟渠豹蛛Pardosa laura成熟雄蛛的求偶延迟时间和触肢伸展次数作为参数,观察研究了雄蛛通过视觉与处女雌蛛拖丝单独和共同诱导情况下的求偶反应,发现视觉是触发雄蛛求偶行为的主要信号,而雌蛛的拖丝则不能单独激发雄蛛的求偶行为,表明雄蛛能够通过视觉接受雌蛛的信号。在此基础上,又测定了雄蛛通过视觉接受亚成体雌蛛、处女雌蛛和交配未产卵雌蛛信号时的求偶反应,发现雄蛛对处女雌蛛和交配未产卵雌蛛的求偶动作次数显著多于亚成体雌蛛,表明雄蛛能够通过视觉区分雌蛛是否成熟,但是仅依靠视觉无法判断雌蛛是否已经交配。本实验表明视觉在沟渠豹蛛雄蛛对雌蛛识别过程中起着非常重要的作用,再次证实狼蛛的视觉比较发达。     

Helminth species diversity of mammals: parasite species richness is a host species attribute

Studies investigating parasite diversity have shown substantial geographical variation in parasite species richness. Most of these studies have, however, adopted a local scale approach, which may have masked more general patterns. Recent studies have shown that ectoparasite species richness in mammals seems highly repeatable among populations of the same mammal host species at a regional scale. In light of these new studies we have reinvestigated the case of parasitic helminths by using a large data set of parasites from mammal populations in 3 continents. We collected homogeneous data and demonstrated that helminth species richness is highly repeatable in mammals at a regional scale. Our results highlight the strong influence of host identity in parasite species richness and call for future research linking helminth species found in a given host to its ecology, immune defences and potential energetic trade-offs.     

Population dynamics of species with gynogenetic sibling species

Models are formulated for the population dynamics of a monoecious or dioecious species with an all-female parthenogenetic sibling species which is also gynogenetic. Continuous, deterministic reproduction and mortality, a stationary age distribution, random mating, and limited sexual competence for all individuals are posited. It is also supposed that in the dioecious case males do not distinguish between true and gynogenetic females. Similarly, hermaphrodites do not differentiate hermaphrodites and gynogens. The model implies that extinction is highly likely in the dioecious situation, but much less so in the monoecious one. Empirical evidence is reviewed and related to the assumptions and conclusions.     

Phylogenetic species recognition and species concepts in fungi

The operational species concept, i.e., the one used to recognize species, is contrasted to the theoretical species concept. A phylogenetic approach to recognize fungal species based on concordance of multiple gene genealogies is compared to those based on morphology and reproductive behavior. Examples where Phylogenetic Species Recognition has been applied to fungi are reviewed and concerns regarding Phylogenetic Species Recognition are discussed.     

Distinguishing species

Given two organisms, how can one distinguish whether they belong to the same species or not? This might be straightforward for two divergent organisms, but can be extremely difficult and laborious for closely related ones. A molecular marker giving a clear distinction would therefore be of immense benefit. The internal transcribed spacer 2 (ITS2) has been widely used for low-level phylogenetic analyses. Case studies revealed that a compensatory base change (CBC) in the helix II or helix III ITS2 secondary structure between two organisms correlated with sexual incompatibility. We analyzed more than 1300 closely related species to test whether this correlation is generally applicable. In 93%, where a CBC was found between organisms classified within the same genus, they belong to different species. Thus, a CBC in an ITS2 sequence-structure alignment is a sufficient condition to distinguish even closely related species.     

Exotic species richness and native species endemism increase the impact of exotic species on islands

Aim Exotic species pose one of the most significant threats to biodiversity, especially on islands. The impacts of exotic species vary in severity among islands, yet little is known about what makes some islands more susceptible than others. Here we determine which characteristics of an island influence how severely exotic species affect its native biota. Location We studied 65 islands and archipelagos from around the world, ranging from latitude 65° N to 54° S. Methods We compiled a global database of 10 island characteristics for 65 islands and determined the relative importance of each characteristic in predicting the impact of exotic species using multivariate modelling and hierarchical partitioning. We defined the impact of exotic species as the number of bird, amphibian and mammal (BAM) species listed by the International Union for Conservation of Nature (IUCN) as threatened by exotics, relative to the total number of BAM species on that island. Results We found that the impact of exotic species is more severe on islands with more exotic species and a greater proportion of native species that are endemic. Unexpectedly, the level of anthropogenic disturbance did not influence an island's susceptibility to the impacts of exotic species. Main conclusions By coupling our results with studies on the introduction and establishment of exotic species, we conclude that colonization pressure, or invasion opportunities, influences all stages of the invasion process. However, species endemism, the other important factor determining the impact of exotic species, is not known to contribute to introduction and establishment success on islands. This demonstrates that different factors correlate with the initial stages of the invasion process and the subsequent impacts of those invaders, highlighting the importance of studying the impacts of exotic species directly. Our study helps identify islands that are at risk of impact by exotics and where investment should focus on preventing further invasions.