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101.
The Formosan subterranean termite, Coptotermes formosanus, with its huge colonies, is a major urban pest in several southern states and Hawaii as well as in South Asia. Because of their cryptic nature (underground habitat) and very long life cycle, not much is known about molting in termite workers. In C. formosanus, the workers stop foraging and lose their gut fauna, respectively, approximately 10 and 5 days prior to ecdysis. In any given colony an average of 1.01% (range 0.6-1.8) of the workers were found to molt each day under laboratory conditions. Workers destined to molt become sluggish and their head capsules develop a mottled texture one day prior to ecdysis. Ecdysis was generally accomplished with the assistance of other workers, which also fed on the exuviae. Immediately after molting worker mandibles were light pink in color and became fully melanized approximately two days later. Gut fauna were acquired on the fourth day after molting. Flagellates were transferred as small encysted cells from other workers through proctodeal feeding. Juvenile hormone III titer ranged between 30-41 pg/mg bodyweight in all stages except in workers sampled 6 days prior to ecdysis. In these workers the titer was 80.5 pg/mg. The high juvenile hormones (JH) titer may also be involved in causing defaunation. Ecdysteroid titer increased from 2.1 pg/mg in non-molting workers to 359.5 and 332.4 pg/mg one and two days following defaunation, respectively. There was a second smaller peak two days prior to ecdysis.  相似文献   
102.
Taxonomic relationships between Rhabdorrhynchus and Pachycerus are discussed, and two new species of Rhabdorrhynchus are described: Rhabdorrhynchus sauditus (type locality: Saudi Arabia, As Shāqqah al Yamānīyah, 19°42'N, 40°48'E) and Rhabdorrhynchus emir (type locality: United Arab Emirates, Jebel Ali, 24°59'N, 55°43'E). Some hypotheses on the distribution of the new species in the Arabian Peninsula, based on a biogeographical analysis, are proposed.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 152 , 25–37.  相似文献   
103.
The Kibish faunal remains are useful for reconstructing the habitat of the earliest documented Homo sapiens and for understanding the community within which early modern humans existed. A diverse assemblage of large mammals, including many species of bovids, suids, and equids, has been recovered from the Kibish Formation. There are no extinct large mammals represented in the fossil assemblage, and the overall taxonomic composition of the fossil fauna is similar to the modern-day wildlife community living near the Omo River. The fossil faunal assemblage shows a paucity of arboreal primates, and carnivore species are rare. However, the faunal sample includes possible Cephalophus (duiker) remains and Hylochoerus meinertzhageni (giant forest hog), taxa that are extremely rare in the African fossil record, and both indicate more closed habitats. Comparative analyses of the Kibish faunal remains using the ecological-diversity approach document close associations with edaphic grassland and woodland vegetation types. These vegetation forms are similar to current habitats surrounding the Omo River.  相似文献   
104.
为探明长期施肥与土壤动物群落之间的关系,于2001年6月至2002年10月,在陕西黄土区对不同施肥条件下的农田土壤动物类群的群落组成和结构进行了研究.在6种不同施肥处理的小区内,即对照组(不施肥,简称CK)、撂荒(不施肥、不耕作、不种植,简称ABAND)、施氮磷钾(简称NPK)、施氮磷钾+秸秆(简称SNPK)、施氮磷钾+有机肥(简称MNPK)和施1.5倍MNPK(简称1.5MNPK),两年4次共采集了72个定点土壤样品.采用手捡法和Cobb过筛法共获得农田土壤动物标本5495个,隶属6门11纲22目61科2亚科35属.结果显示6种施肥处理中,大型农田土壤动物的个体总数从多到少依次为SNPK>1.5MNPK>NPK>ABAND>MNPK>CK,类群数依次是1.5MNPK>NPK>SNPK>CK>ABAND=MNPK.中小型农田土壤动物个体总数由多到少依次为1.5MNPK>MNPK>ABAND>SNPK>NPK>CK,类群数依次是SNPK=MNPK>CK=NPK=1.5MNPK>ABAND.大型农田土壤动物个体数和类群数分布最多的分别是SNPK和1.5MNPK处理,而中小型农田土壤动物则分别是1.5MNPK和SNPK处理.表明农田土壤动物类群分布与施肥处理有关.农田土壤动物优势类群分布以施氮磷钾(NPK)小区最多,常见类群以对照组(CK)最多,极稀有类群以施1.5倍MNPK小区最多.群落相似性指数分析结果表明,在不同施肥处理之间,农田土壤动物的相似性系数一般较低,而其群落组成的异质性较高如大型土壤动物群落在撂荒地与其他施肥处理之间的相似性明显低于其他各施肥处理之间;而中小型土壤动物群落在对照小区与其他施肥之间的相似性指数明显低于其他各施肥处理之间,反映出不同施肥处理对土壤生态系统内部环境,进而对土壤动物群落产生的影响.  相似文献   
105.
甘肃临夏盆地晚中新世大唇犀化石的年龄结构与生活环境   总被引:4,自引:4,他引:0  
甘肃临夏盆地的晚中新世红粘土堆积中含有大量的三趾马动物群化石,其中犀科化石,特别是大唇犀最为丰富。通过对临夏盆地晚中新世具有代表性的大唇犀化石的年龄结构的分析,初步了解到化石群各年龄段个体的百分比和种群动态。大唇犀化石中成年个体的数量占优势,明显多于老年个体,与正常生活群中的年龄结构吻合,由此可初步断定是突发性事件引起了犀牛种群的灾害性死亡。再进一步对化石的风化、磨蚀、聚集状态及所受的水动力特征等进行分析,发现骨骼受到了弱水流的短距离搬运,说明化石埋藏地离动物死亡地不远。以上分析结果与沉积学特征相结合,说明临夏盆地晚中新世三趾马动物群的集群死亡可能与严重的干旱化事件有关。  相似文献   
106.
横断山区蚜虫区系的特异性与历史渊源   总被引:4,自引:1,他引:3  
文章系统分析了横断山区蚜虫区系的特异性,主要表现在:区系成分的复杂性、古北与东洋成分的交融性、区系组成的特有性和物种分布的间断性.进一步结合地质历史事件对横断山区蚜虫区系的历史渊源及其特异性演化进行了初步讨论.根据蚜虫类分布特点,建议古北区和东洋区在横断山区的分界线南移至丽江一线;横断山区蚜虫和其他地区的间隔分布可能是由地质历史上板块运动和青藏高原的隆升及第四纪冰期-间冰期的循环往复造成的;横断山区蚜虫区系是一个复合区系,同其他动物地理区划如新北区、澳洲区、非洲区等的蚜虫区系都有密切的历史渊源,青藏高原和横断山区的隆起及第四纪冰期-间冰期的循环往复又使得本区蚜虫区系有着独特的演化历程,从而造成了本区蚜虫区系的特有性.  相似文献   
107.
通过对山东新汶煤田太原组小有孔虫动物群的系统研究,共鉴定出小有孔虫化石24属66种,根据小有孔虫在太原组中的垂向分布和含量的变化,自下而上分为3个小有孔虫组合:1.Brad yina samarica- Palaeotextularia angusta elongata组合,2.Nodosaria sinensis- Tetrataxis组合,3.Geinitzina postacarbonica组合。通过与邻区及华北部分地区的对比,本区太原组小有孔虫动物群的地质时代应归属于早二叠世,其层位大致相当于华北各地太原组(ting)类的Pseudoschwagerina带。  相似文献   
108.
记述了发现于陕西镇安黄家湾早更新世晚期的一个大型哺乳动物群。动物群包括哺乳动物4目、11科、24种,它们是:Canis variabilis, Hyaenidae gen. et sp. indet. , Homotherium sp. , Megantereon sp. , Lynx cf. shansius , Panthera pardus , Elephantidae gen. et sp. indet. , Equus qingyangensis , Hesperotherium sinense , Ancylotherium sp. , Megatapirus augustus, Rhinocerotidae gen. et sp. indet. , Dicerorhinus lantianensis, Sus sp. , Moschus moschi ferus , Cervus unicolor , Cervus sp. 1, Cervus sp. 2, Hydropotes sp. , Capreolus sp. , Strepsiceros annectens , Leptobos sp. , Bubalus sp. 和 Budorcas taxicolor等。动物群伴生植物孢粉分析表明,当时在化石产地生长着下列植物:Selaginella sp. , Pinaceae gen. et sp. indet. , Picea sp. , Cotinus coggygria , Juglans regia , Quercus sp. , Myrica rubra , Meliaceae gen. et sp. indet. , Celtis sp. , Oleaceae ( Syringa sp. ?) gen. et sp. indet. , Chenopodiaceae gen. et sp. indet. ,Kobresia sp. , Scrophulariaceae gen. et sp. indet. , Humulus sp. , Gramineae gen. et sp. indet. , Ranunculaceae gen. et sp. indet. , Sparganium sp. ,Celastraceae gen. et sp. indet. ,Elaeagnaceae gen. et sp. indet. ,Compositae gen. et sp. indet. ,Aremisia sp. , Xanthium sibiricum 和Carex sp.等。分析了动物群生活时栖息地的气候、植被和地貌特征,结果表明,动物群栖息在温暖、湿润、有森林、灌丛草地并富有水体的生境中,当时秦岭腹地存在着相当开阔的河谷地带,山势没有现在这么险峻,因此阻断秦岭南北动物交流的天然屏障当时可能还未真正形成,秦岭南北两侧的动物可以沿着开阔的河谷地带随季节和气候的变化互相扩散迁移。  相似文献   
109.
The Asbole area in the Lower Awash Valley yielded a diverse fauna of large and small mammals, associated with an Acheulean industry. The most notable forms are a potentially new species of herpestid, a large collection of Kolpochoerus majus, and the earliest known Bos in Africa. Biochronologically, this fauna belongs to the earliest Middle Pleistocene, and is roughly contemporaneous with the Bodo site further south. Paleoenvironmentally, the fauna suggests a mosaic of landscapes among which humid environments, grasslands and forests, are predominant.  相似文献   
110.
A faunistic study investigating the potential side-effects of corn (Zea mays) genetically modified to express a truncated Cry1Ab protein derived from Bacillus thuringiensis subsp. kurstaki, on non-target arthropods was carried out under field conditions. The communities of non-target arthropods in the soil, on the leaves and flying in the crop area were monitored throughout the growing season. Water-treated, untransformed corn served as a control, and a spray application of a bacterial Bt insecticide (Delfin WG) and a synthetic insecticide (Karate Xpress) used to control the European corn borer (Ostrinia nubilalis; Lepidoptera: Pyralidae) acted as positive reference treatments. Results were analyzed using a principal response curve. Significantly lower infestations by the lepidopteran target species O. nubilalis were observed in the Bt-corn plots compared to the control. No effects of Bt-corn on the communities of soil dwelling and non-target plant dwelling arthropods were observed. A trend towards a community effect on flying arthropods was observed with lower abundance of adult Lepidoptera, flies in the families Lonchopteridae, Mycetophilidae and Syrphidae, and the hymenopteran parasitoids Ceraphronidae. Effects were weak and restricted to two sampling dates corresponding to anthesis. A short but statistically significant effect of Karate Xpress and Delfin was observed on the community of plant dwellers and a prolonged effect of Karate Xpress on the soil dwellers.  相似文献   
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