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排序方式: 共有225条查询结果,搜索用时 15 毫秒
51.
IAN M. KING 《Bioacoustics.》2013,22(1):19-29
ABSTRACT Although chorusing behaviour has been reported previously in six species of corixid water bugs, including one European species of Micronecta, no analysis of chorusing has been published for Micronecta. Studies of a large pond in SE Australia show that chorusing occurred in the most common species of Micronecta in the study area, M. concordia. Pulse-trains synchronized with those of other individuals nearby were the predominant acoustic output of M. concordia males throughout the stridulating season, from mid-winter to mid-summer. At the start of the season, chorusing began with an exponential increase in the percentage of synchronized signals over a period of six days. 相似文献
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53.
Predator foraging behaviour affects the outcome of enemy–enemy interactions. Using a combination of fieldwork and laboratory experiments, we show that intraguild predation may be important in the field distribution of generalist predators that share a common prey: the eggs (and larvae) of the leaf beetle Phratora vulgatissima, a major insect pest in coppicing willow plantations. We focused on a species from the hoverfly genus Parasyrphus (Syrphidae), which may exhibit large temporal and spatial variation in density. Predator and prey densities were quantified in 40 field plots in willow plantations. The likelihood of finding hoverfly eggs declined with increasing densities of two predatory mirids, Orthotylus marginalis and Closterotomus fulvomaculatus, which exhibit less mobile behaviour similar to that of hoverfly larvae. The density of a more mobile predatory bug species, the anthocorid Anthocoris nemorum, was not associated with hoverfly occurrence. These results corroborate the hypothesis that less mobile predators should be stronger intraguild predators than mobilepredators. Further partial support for this hypothesis was obtained in the laboratory study where individual predators were presented with clutches of P. vulgatissima eggs containing one hoverfly egg: the less mobile C. fulvomaculatus and O. marginalis tended to consume the hoverfly egg more readily than the more mobile A. nemorum. However, most individuals of all three bug species consumed the egg of the potential competitor – the syrphid – within 24 h. The field study also showed that hoverfly occurrence was positively associated with the density of their prey and with the presence of nearby forests. We conclude that intraguild predation, abundance of prey and the surrounding habitat affect the distribution of hoverflies in this system and should be considered when developing biological control methods. 相似文献
54.
Hurwitz I Fieck A Read A Hillesland H Klein N Kang A Durvasula R 《International journal of biological sciences》2011,7(9):1334-1344
Conventional methodologies to control vector borne diseases with chemical pesticides are often associated with environmental toxicity, adverse effects on human health and the emergence of insect resistance. In the paratransgenic strategy, symbiotic or commensal microbes of host insects are transformed to express gene products that interfere with pathogen transmission. These genetically altered microbes are re-introduced back to the insect where expression of the engineered molecules decreases the host's ability to transmit the pathogen. We have successfully utilized this strategy to reduce carriage rates of Trypanosoma cruzi, the causative agent of Chagas disease, in the triatomine bug, Rhodnius prolixus, and are currently developing this methodology to control the transmission of Leishmania donovani by the sand fly Phlebotomus argentipes. Several effector molecules, including antimicrobial peptides and highly specific single chain antibodies, are currently being explored for their anti-parasite activities in these two systems. In preparation for eventual field use, we are actively engaged in risk assessment studies addressing the issue of horizontal gene transfer from the modified bacteria to environmental microbes. 相似文献
55.
Anjali Km. Prasad 《法国昆虫学会纪事》2013,49(6):428-433
The polyphagous pest Helopeltis theivora Waterhouse (Heteroptera: Miridae) is one of the major pests of tea [Camellia sinensis, (Theaceae)]. Duranta repens (Verbenaceae), an ornamental plant producing various allelochemicals, is used in many tea estates as hedge plant. This plant was earlier reported to be an alternative host of H. theivora. To gain an insight into the pest and host–plant relationships, the present work reports studies on host-based life-cycle traits, pesticide tolerance status and levels of detoxification enzymes, such as general esterases (GEs), glutathione S-transferases (GSTs) and cytochrome P450 (CYP450). Host switching in the development of pesticide tolerance in H. theivora was evident. While comparing the biology of this pest on the primary host (tea) and the alternative host (D. repens) it was found that total developmental period was higher in the Duranta-reared population, along with significantly higher nymphal mortality and significantly less fecundity. However, there was no significant difference in incubation period, hatchability, sex ratio, pre-oviposition period and adult longevity. Susceptibility of the Duranta-reared population against quinalphos (a commonly used insecticide) was 1.41 times less than the tea-reared H. theivora population. The host-based variation in the relative susceptibility against insecticide was corroborated by differential activity of the three major xenobiotic detoxifying enzymes mentioned above. GE, GST and CYP450 activities were 2.67-fold, 1.43-fold and 1.37-fold higher in the Duranta-reared population than in the tea-reared population, possibly signifying that host switching can play a role in the development of tolerance of H. theivora against insecticides. 相似文献
56.
Chia-Hao Chin Shu-Hwa Chen Chun-Yu Chen Chao A. Hsiung Chin-Wen Ho Ming-Tat Ko Chung-Yen Lin 《Gene》2013
As is generally assumed, clusters in protein–protein interaction (PPI) networks perform specific, crucial functions in biological systems. Various network community detection methods have been developed to exploit PPI networks in order to identify protein complexes and functional modules. Due to the potential role of various regulatory modes in biological networks, a single method may just apply a single graph property and neglect communities highlighted by other network properties. 相似文献
57.
58.
I. M. KING 《Bioacoustics.》2013,22(2-3):115-130
ABSTRACT The role of male sounds in attracting females and in mating was investigated in the three most common species of Micronecta found in ponds 60 km NE of Melbourne, Australia: M. concordia, M. tasmanica and M. robusta. In playback experiments using recorded male signals, females were attracted to signals of conspecific males, in preference to signals of heterospecific sympatric males. Studies of mating behaviour, using video recording, showed that signals were obligatory for mating. These findings strongly suggest that acoustic signalling is important in reproductive isolation in Micronecta. Comparisons between matings and rejected matings showed that, within each species, copulation only occurred following a certain minimum number of acoustic signals with more pulse-trains than the mean for the species. Low amplitude sounds (after signals) were also important in courtship, immediately preceding mating. No sounds occurred during copulation. 相似文献
59.
红树植物是一类生长在热带、亚热带海岸潮间带的乔木、灌木或草本植物,根据其分布特征可分为真红树植物植物和半红树植物。为了探究两者对海岸潮间带高盐、高光和缺氧等环境的生态适应策略的异同,该文选取5种真红树植物植物[卤蕨(Acrostichum aureum)、木榄(Bruguiera gymnorrhiza)、老鼠簕(Acanthus ilicifolius)、桐花树(Aegiceras corniculatum)、秋茄(Kandelia candel)]和4种半红树植物[银叶树(Heritiera littoralis)、水黄皮(Pongamia pinnata)、黄槿(Hibiscus tiliaceus)、杨叶肖槿(Thespesia populnea)]为研究对象,对叶片解剖和功能性状进行了对比研究。结果表明:(1)9种红树植物叶片的共同特征表现为均具有角质层、叶肉具有栅栏组织和海绵组织分化、气孔下陷等。(2)不同之处在于真红树植物植物叶片有蜡质层和内皮层、无表皮毛、气孔仅分布在下表皮,而半红树植物的叶片则较少有蜡质层,部分有表皮毛,无内皮层,气孔在上下表皮分布不完全一致。(3)真红树植物植物的气孔密度和比叶面积显著小于半红树植物(P<0.05),而叶片厚度、含水量、比叶重和鲜干重比则显著大于半红树植物(P<0.05)。以上结果说明真红树植物植物的叶片性状使其在维持盐度平衡及贮水保水能力方面强于半红树植物,从而能更好地适应海岸潮间带高盐环境。 相似文献
60.
André MJ 《Bio Systems》2011,103(2):239-251
In closed systems, the O2 compensation point (ΓO) was previously defined as the upper limit of O2 level, at a given CO2 level, above which plants cannot have positive carbon balance and survive. Studies with 18O2 measure the actual O2 uptake by photorespiration due to the dual function of Rubisco, the enzyme that fixes CO2 and takes O2 as an alternative substrate. One-step modelling of CO2 and O2 uptakes allows calculating a plant specificity factor (Sp) as the sum of the biochemical specificity of Rubisco and a biophysical specificity, function of the resistance to CO2 transfer from the atmosphere to Rubisco. The crossing points (Cx, Ox) are defined as CO2 and O2 concentrations for which O2 and CO2 uptakes are equal. It is observed that: (1) under the preindustrial atmosphere, photorespiration of C3 plants uses as much photochemical energy as photosynthesis, i.e. the Cx and Ox are equal or near the CO2 and O2 concentrations of that epoch; (2) contrarily to ΓC, a ΓO does not practically limit the plant growth, i.e. the plant net CO2 balance is positive up to very high O2 levels; (3) however, in a closed biosystem, ΓO exists; it is not the limit of plant growth, but the equilibrium point between photosynthesis and the opposite respiratory processes; (4) a reciprocal relationship exists between ΓO and ΓC, as unique functions of the respective CO2 and O2 concentrations and of Sp, this invalidates some results showing two different functions for ΓO and ΓC, and, consequently, the associated analyses related to greenhouse effects in the past; (5) the pre-industrial atmosphere levels of O2 and CO2 are the ΓO and ΓC of the global bio-system. They are equal to or near the values of Cx and Ox of C3 plants, the majority of land plants in preindustrial period. We assume that the crossing points represent favourable feedback conditions for the biosphere-atmosphere equilibrium and could result from co-evolution of plants-atmosphere-climate. We suggest that the evolution of Rubisco and associated pathways is directed by an optimisation between photosynthesis and photorespiration. 相似文献