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51.
用不同温度对三带喙库蚊卵的保存进行了试验,发现蚊卵在10℃条件下仅可保存两天,而2℃、5℃、11℃以上等其他温度均不宜保存.因此证实该蚊卵不能在任何温度下作长时间保存。通过实验观察了以6种不同配方的食料饲养三带喙库蚊幼虫,结果显示用鱼粉、面粉、酵母粉组合成的6号组食料经综合分析优于其他组食料。进一步说明动物蛋白的种类、配比对蚊幼虫的存活、健康关系极大。 相似文献
52.
Kirsty Barr Henrik Moller Emma Christmas Philip Lyver Jacqueline Beggs 《Oecologia》1996,105(2):266-270
An introduced social wasp Vespula vulgaris may compete with native birds for honeydew and invertebrates in New Zealand forests. Experimentally hidden mealworms (Tenebrio molitor) persisted longer at two sites following wasp poisoning that at two sites where wasps were not poisoned. Mealworms persisted longer in the morning than in the afternoon within all study sites. An unusually low mealworm removal rate during a morning trial before wasp poisoning heavily influences the results of this experiment but we have no ecological reason to ignore it. Wasps may therefore be having a heavy impact on invertebrate abundance on very short time scales (within a day following dawn emergence). They may also remove cached food items that would otherwise be retrieved by the South Island robin (Petroica australis australis) during cold or dark feeding conditions. 相似文献
53.
Food habits of sika deer on the Boso Peninsula,central japan 总被引:6,自引:0,他引:6
The rumen contents of sika deer (Cervus nippon Temminck) on the Boso Peninsula, central Japan, were analyzed to identify local, sexual and age-specific differences in food
habits. Graminoids and woody plants were the primary foods throughout the year. In winter, the use of evergreen broad leaves
increased. The food habits of sika deer on Boso Peninsula were intermediate between those of populations inhabiting northern
and southern Japan. Acorns, mainlyLithocarpus edulis Nakai, were consumed in fall and winter with a peak in October. Since the availability of acorns is not influenced by foraging
in previous years, it can be regarded as a stable food supply and hence may be important for deer on the Boso Peninsula. The
local difference between the Amatsukominato (AT) area, having a large plantation ofLithocarpus producing acrons, and the Kamogawa-Katsuura (KK) area, having a small plantation ofLithocarpus, was recognized; seeds and fruit were consumed more in AT than in KK in fall and winter. Males consumed more seeds and fruit
than females at both sites in fall. This can be attributed to sexual differences in nutritional requirement. 相似文献
54.
猪脑组织水解液及其益智食品的研制 总被引:1,自引:0,他引:1
本文初步探讨了多脂质物质(脑组织)水解条件的优化过程及其益智产品的研制。经过多项对比实验得出了以双酶分段水解以及水化法除脂质提取脑组织水解液的初步工艺,并通过微震化工艺达到了掩蔽不良气味,稳定有效成分的效果。 相似文献
55.
Many deterministic models of sexually transmitted diseases, as well as population models in general, contain elements of stochastic or statistical reasoning. An example of such a model is that of Dietz and Hadeler (1988) concerning sexually transmitted diseases in which there is partnership formation and dissolution. Among the interesting formulas in this paper, which enter into the analysis of the model, are those for the expected number of partners a male or female has during a lifetime. To a probabilist such formulas suggest the possibility that some stochastic process may be constructed so as to yield these formulas as well as others that may be of interest. The principal purpose of this paper is to demonstrate that such a stochastic process does indeed exist in the form of a three state semi-Markov process in continuous time with stationary laws of evolution and with a one-step density matrix determined by four parameters which were interpreted as constant latent risk functions in the classical theory of competing risks. This construction of a semi-Markov process not only provides a framework for the systematic derivation of the formulas of Dietz and Hadeler but also suggests pathways,for extensions to the age-dependent case.This research was partially supported by NATO Grant D.890350 相似文献
56.
Studies were undertaken on interactions between panicle size, insect density, host plant, and the environment for sorghum
head bug,Calocoris angustatus Lethiery on five sorghum genotypes in terms of bug population increase, grain damage and loss in grain mass across four panicle
sizes (5, 10 or 20 branches/panicle and whole panicle), and three infestation levels (5, 10 and 15 pairs of bugs/panicle).
Head bug numbers increased and grain damage decreased with an increase in panicle size in the head bug susceptible cultivars,
CSH 1 and CSH 5. However, the increase in bug numbers or decrease in grain damage was not significant in head bug resistant
genotypes, IS 17610 and IS 17645. Head bug numbers increased with an increase in infestation level in CSH 1 and CSH 5, however,
such an increase was not substantial in IS 17610 and IS 17645. Grain damage was significantly lower in IS 17610 and IS 17645
compared with CSH 1 and CSH 5 across infestation levels. Head bug population increased at a greater rate during the rainy
season compared with the dry season. Panicle size and infestation levels accounted for greater variation in grain damage and
percentage loss in grain mass during the rainy season than in the dry season. To identify reliable sources of resistance to
insects, it is important to study insect host plant-interactions across panicle sizes (levels of food availability), infestation
levels and seasons. 相似文献
57.
Feeding selectivity by five epilithic, case-building trichopteran species from a first-order stream was examined using laboratory experiments. Larvae had the choice of three food types: periphyton and detritus from the stream, and nettle broth as an artificial food source. Food type influenced the microdistribution of these species. Larvae were able to distinguish between different food types and showed species-specific responses to the various types of food. Drusus annulatus, Micrasema longulum and Apatania fimbriata favoured periphyton, while Agapetus fuscipes and Silo pallipes showed no preference for periphyton over detritus. Four of the five species examined (Apatania fimbriata was the exception) tended to avoid nettle broth. The complexity of foraging behaviour was illustrated by M. longulum. Given a choice between detritus, periphyton and periphyton with the addition of moss, they clearly preferred the latter food type, scraping mostly on the epiphytic algae. Proportions of a given species selecting periphyton were correlated with percentage areas of algae in the gut contents of that species in the field. D. annulatus, M. longulum and A. fimbriata showed the greatest preference for periphyton, and consumed the highest proportions of algae in the field. A. fuscipes and S. pallipes often selected detritus, and these species had the lowest proportions of algae, and the highest proportions of detritus, in their guts. 相似文献
58.
59.
Repeated measurements of food intake made on juvenile Arctic charr, Salvelinus alpinus , held under different rearing conditions enabled examination of the effects of environmental manipulations on both intra– and inter–individual variations in food intake to be made. This permitted the assessment of the influences of differential food acquisition on individual growth rates and biomass gain. When charr were held in isolation individual fish showed relatively little day–to–day variability in food intake and inter–individual differences in intake were small ('base–fine' values). All fish exhibited positive rates of growth and the overall range was narrow. Nevertheless, there was a highly significant positive correlation between food intake and growth, indicating that those individuals that consumed the greatest quantities of food were also those that had the highest rates of weight gain. The rearing of charr in groups led to increases in both intra– and inter–individual variations in food intake to levels considerably above 'base–line'. This increased variability in food intake was reflected in rates of weight gain being more variable amongst the charr reared in groups, with fish that lost weight often being recorded. Manipulation of the rearing environment had marked influences upon intra–individual variability in food intake, inter–individual differences in food acquisition and rates of weight gain. High stocking densities and exposure of the fish to moderate water currents were most effective in reducing levels of variability to approach those observed under 'base–line' conditions. 相似文献
60.
Gold-labeled insulin is bound first of all to the cilia of the oral field of Tetrahymena. A primary treatment (hormonal imprinting) with insulin increases the binding capacity even after 24h and makes it more sensitive for appearance a week later, within a minute of giving insulin-gold. The food vacuoles contain insulin-gold in pretreated cells or without pretreatment as well, though in imprinted situations the label can be found in pinocytotic vesicles at the bases of cilia in the oral field. Altogether, a functional difference can be observed between the cilia of the oral and non-oral surfaces of Tetrahymena and hormonal imprinting has a specifying effect on the binding of labeled hormone. 相似文献