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This is the first detailed study of the post-natal development of Aethomys chrysophilus. Physical measurements were taken from 37 litters consisting of 116 young, and the behaviour of 37 young from 12 litters was observed. The physical development of the young is described and the weight and linear increases analysed. Litter size varied between one and five with an average of 3,1 young per litter for 37 litters. The minimum age of sexual maturity was approximately 82 days, and the shortest interval between litters was 26 days. Major behavioural changes were found at six, 12 and 26 days, and on this basis the post-natal development is divided into Neonatal (0-5 days). Transition (6-11 days), Infantile (12-25 days) and Juvenile (26-82 days) periods. Nipple-clinging dominated the early stages of development and the modifications of the incisors for this purpose are described. The parent-young relationship and mortality of the young are discussed. In addition, the post-natal development of A. chrysophilus is compared with that of three other South African murids, namely Aethomys namaquensis, Thallomys paedulcus and Praomys (Mastomys) natalensis.  相似文献   
13.
在整理已采集的标本时,经观察鉴定发现有派伦螨科(Parholaspidae)卡盾螨属(Krantzholaspis)1新种.本文就新种的形态特征作了描述,模式标本保存在沈阳农业大学植保系。  相似文献   
14.
Soil faunal communities are often phylogenetically diverse and the accurate assessment of the taxonomic structure of these communities is both time-consuming and requires a high level of taxonomic expertise. Here we describe a DNA sequence-based methodology for characterizing soil micro- and mesofaunal communities that is similar to the molecular approaches commonly used to survey soil microbial diversity. The technique involves the direct extraction of faunal DNA from soil, PCR amplification of the extracted DNA with metazoan-specific primers, followed by the construction of clone libraries and direct sequencing of individual PCR products. We used this technique to characterize micro- and mesofaunal community composition from six individual soils representing two land-use types. The technique captured the more abundant faunal groups in the soils (nematodes, Collembola, Acari, tardigrades, enchytraeids) and provided sufficient taxonomic resolution to describe the overall structure of the communities. We compared the results obtained using this molecular approach to results obtained using a traditional, microscopy-based approach and found that the results were broadly similar. However, since biases are inherent in both methods it remains unclear which method provides a more accurate assessment of soil faunal community composition. Although this molecular approach has some distinct disadvantages over the more widely-used direct extraction methods, one advantage is that the taxonomic identification it can provide will be more accurate and consistent across research groups, facilitating effective comparisons of mesofaunal surveys.  相似文献   
15.
珠甲螨科分类研究进展(蜱螨亚纲:甲螨目:珠甲螨总科)   总被引:1,自引:0,他引:1  
全面回顾了世界珠甲螨科约210年的研究历史,介绍了分类研究的代表人物及其所取得的成就。对中国珠甲螨科的分类研究进行了回顾,同时介绍了世界及中国珠甲螨科的各属种的地理分布。指出了该科分类研究中目前存在的主要问题,并对今后的研究工作进行了展望。  相似文献   
16.
Phenolic compounds have been shown in several studies to have important ‘carryover effects’ on litter decomposition, microbial nutrient immobilization and nutrient availability. These effects arise in part because of the adverse effect they have on the feeding activities of litter-feeding invertebrates such as micro-arthropods that drive decomposition processes. However, the interactive effects of phenolic compounds and soil micro-arthropods on litter decomposition are poorly understood. Phenolic compounds can easily be removed by acetone rinsing from living lichens, allowing us to specifically test the role that phenolic compounds (and their removal) have in controlling the effects of micro-arthropods on the decomposition of their litter. We performed a litter-bag experiment aimed at exploring how lichen litter mass loss and nutrient release during decomposition was affected by phenolics (by using acetone rinsed and non-rinsed lichen material) and micro-arthropod activity (by using different mesh sizes to allow or exclude entry by micro-arthropods) for each of six contrasting lichen species (Cladonia rangiferina, Cladonia stellaris, Evernia prunastri, Hypogymnia physodes, Pseudevernia furfuracea and Usnea dasypoga). Both the removal of phenolic compounds and the presence of micro-arthropods accelerated mass and nutrient release overall, but not for either of the two Cladonia species. Removal of phenolics also had an overall positive effect on the effects of arthropods on the loss of P, but not mass and N, from the decomposing lichens. Further, for U. dasypoga, but not the other species, natural levels of phenolic compounds deterred micro-arthropods from accelerating mass loss, and the removal of these compounds enabled micro-arthropods to enhance its decomposition. Our findings that lichen phenolic compounds can sometimes interact with micro-arthropods to influence lichen litter mass loss and nutrient release during decomposition assists our understanding of how lichens and their consumers may impact on organic matter dynamics, biochemical nutrient cycling and other related ecosystem processes.  相似文献   
17.
蒲螨是一类寄生鳞翅目、鞘翅目和膜翅目等昆虫的外寄生螨,寄生导致寄主麻痹甚至死亡。本文对蒲螨的分类学、生物学和生态学研究进展、国内外作为天敌的利用情况以及蒲螨体内提取的昆虫特异性神经毒素tox34的使用情况进行了综述。  相似文献   
18.
中国皮刺螨总科名录初报(英文)   总被引:1,自引:0,他引:1  
Medical gamasid mite is a general designation of a kind of non-insect arthropod and it can transmit many diseases.Dermanyssoidea is an important part of medical gamasid mite,so 126 new species in 9 genera have been added on the basis of Economic insect fauna of China and through combining many researches on Fauna of Gamasid Mites in China,so the research has enriched and extended the content of dermanyssoidea.  相似文献   
19.
Soil microinvertebrates are closely associated with soil decomposition and nutrient cycles and may be particularly responsive indicators for soil management practices. However, identification of appropriate bioindicator species for many systems has been severely limited by a lack of information on species taxonomy, distribution, and functional role. We evaluated Indicator Species Analysis (ISA) as an objective method for assessing the indicator potential of different taxa without regard to their ecological role or expected management response. Restricting ordination and site classification to significant indicator morphotaxa reduced the dimensionality of the community data matrix by 69% while only slightly decreasing the efficiency of unsupervised classification (from 87.2 to 84.4%); the percentage of total variability explained by first two PCA axes increased following ISA. When these same indicator morphotaxa were used to classify an independent set of samples, the percentage of total variability explained by the first two PCA axes increased from 55.3 to 65.2%; cluster analysis of the test dataset correctly classified 47 out of 50 plots by cover type (94% accuracy). However, restriction of analysis to indicator morphotaxa alone reduced detection of differences between sampling dates relative to the complete dataset. Although care needs to be taken to ensure that the dataset used for indicator selection is fully representative of underlying temporal and spatial variability, ISA appears to overcome many of the limitations associated with parametric and multivariate approaches for identifying indicator morphotaxa and has the potential to greatly reduce the taxonomic expertise and labor costs associated with sorting and identification of soil microarthropods.  相似文献   
20.
Resistance of 37Citrullus lanatus L. lines to the carmine spider mite,Tetranychus cinnabarinus (Boisduval), was evaluated in three laboratory experiments, each including seven plants per line. Infestation with ten adult female mites per leaf, of each plant, was done at the three-leaf stage. In experiment A, average counts 10 days after infestation of three leaves ranged from 42 to 144 mites per leaf. In experiment B, average counts 8 days after infestation of two leaves ranged from 40 to 286 mites per leaf. In experiment C, average counts 8 days after infestation of two leaves ranged from 15 to 196 mites per leaf. The results suggest that a definite variation in resistance against mite infestation exists among watermelon lines. Contribution from the Agricultural Research Organization. No. 1082-E, 1993 series.  相似文献   
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