猕猴桃传粉蜜蜂的初步研究

目的补充淡脉隧蜂亚属中国种类。方法利用昆虫分类学的原理和方法,参考文献资料,进行标本鉴定。结果整理、核实云南省淡脉隧蜂亚属种类,记述云南淡脉隧蜂亚属14种,其中包括1新种：角胸淡脉隧蜂Lasioglossum (Lasioglossum) cerothoracicum Zhang, Niu et Zhu sp. nov.。对新种进行详细描述,并绘制形态特征图。编制了云南省淡脉隧蜂亚属已知种检索表。结论研究结果为中国淡脉隧蜂属的分类研究提供依据和参考,具有重要的理论价值。     

Efficient reduction of biomass,seed and season long pollen production of common ragweed (Ambrosia artemisiifolia L.)

Ragweed (Ambrosia artemisiifolia L.) is a noxious plant that not only is a troublesome agronomic weed that causes economic damage to agricultural crops but also − and even more importantly − causes severe health problems due to its severe allergenicity. The pollen of invasive ragweed has become a major allergenic risk factor in urban areas in newly occupied regions. Many urban areas prohibit herbicide application; thus, mowing is the most widely used control measure. Counting pollen is labour intensive; therefore, pollen production data are mainly based on estimations. Field experiments were conducted to determine the effects of different mowing scenarios, plant density and cutting height on the biomass, pollen production and seed production of common ragweed plants. Ragweed plants were mown twice: just before the flowering of terminal racemes (BBCH 59) and when the flowers of the re-sprouting lateral shoots reached BBCH 59. A 1- to 3-cm cutting height produced the greatest pollen reduction compared to that of intact control plants (94%) based on a season-long pollen collection. The number of female flowers also significantly decreased (97%). Compared to the control, the onset of pollen discharge was delayed by 5 weeks and the length of the pollen discharge period decreased from 9 to 4 weeks. The season-long unique and reproducible pollen production data can be integrated with airborne pollen modelling and population management strategies.     

蚜虫性信息素

蚜虫报警信息素 [(E)-β-farnesene,简称EBF] 是蚜虫腹管分泌的一种物质,它能对同种其他个体产生报警反应,使其迅速逃离危险现场。作为天然蚜虫信息素,EBF通过蚜虫嗅觉系统的气味结合蛋白OBPs和嗅觉受体ORs发挥作用,具有驱避、杀蚜、增效等多种生物活性,可用于蚜虫的行为调控,但由于其结构中存在的共轭双键而导致其稳定性差,从而限制了其实际应用。本文在简介蚜虫报警信息素EBF的基础上,系统介绍了EBF的结构修饰和改造进展,并对EBF及其类似物的生物活性和作用机制进行了综述,最后对EBF及其类似物的应用前景进行了展望,期望为开发具有实用价值的生态友好型蚜虫控制剂提供参考。     

Residents’ perceptions and attitudes toward waste treatment facility sites and their possible conversion: A literature review

The siting a landfill or waste treatment facility and the redevelopment of a brownfield or former landfill site are generally treated as independent issues in the research literature. Nonetheless, the two are important elements of community development and urban revitalization efforts. The purpose of this paper is to provide an integrated review of the current literature on attitudes toward waste treatment sites and their potential conversion for recreation use. We begin by examining research on residents’ perceptions of and attitudes toward proposed and existing waste treatment facility sites, including the perceived impacts and determinants of attitudes toward these sites. Next we summarize work that has explored the subsequent conversion of former landfills or brownfield sites, with a particular emphasis on repurposing these sites for green space and recreation use. We conclude by summarizing key issues and implications for future research and policy development.     

Effects of diazepam and chlordimeform analogs on the German and the American cockroaches

Twenty-one diazepam- and chlordimeform (CDM)-related compounds were synthesized by mimicking some parts of the 1,4-benzodiazepine tranquilizing drugs, and were tested for their insecticidal activity against the German cockroach. Some of these compounds showed knockdown effects and some were insecticidal. Against the German cockroach the most toxic CDM analog was N-propargyl CDM (compound 6), and that with a potent knockdown potency was compound 13 which has a structural resemblance to diazepam. Ligand-receptor binding assay was carried out, using [³H]diazepam as a ligand to examine the relation between CDM-related compounds and the 1,4-benzodiazepines. The [³H]diazepam binding to a specific site in the American cockroach brain was inhibited by the insecticidal compounds. Among these compounds a correlation exists between their inhibitory potency on specific [³H]diazepam binding and their insecticidal activity, suggesting a possible significance of such an interaction with the diazepam binding site for the toxicity of these compounds against cockroaches.     

Evaluation of optical sensor measurements of canopy reflectance and of leaf flavonols and chlorophyll contents to assess crop nitrogen status of muskmelon

Nitrogen losses from intensive vegetal production systems are commonly associated with contamination of water bodies. Sustainable and optimal economic N management requires correct and timely on-farm assessment of crop N status to detect N deficiency or excess. Optical sensors are promising tools for the assessment of crop N status throughout a crop or at critical times. We evaluated optical sensor measurement of canopy reflectance and of leaf flavonols and chlorophyll contents to assess crop N status weekly throughout a muskmelon crop. The Crop Circle ACS 470 was used for reflectance measurement, the SPAD 502 for leaf chlorophyll, and the DUALEX 4 Scientific for leaf chlorophyll and flavonols. Four indices of canopy reflectance (NDVI, GNDVI, RVI, GVI), leaf flavonols and chlorophyll contents and the nitrogen balance index (NBI), the ratio of chlorophyll to flavonols contents, were linearly related to crop N content and to crop Nitrogen Nutrition Index (NNI) throughout most of the crop. NBI most accurately predicted crop N status; in five consecutive weekly measurements, R² values were 0.80–0.95. For NDVI during the same period, R² values were 0.76–0.87 in the first three measurements but R² values in the last two measurements were 0.39–0.45. Similar relationships were found with the three other reflectance indices. Generally, the relationships with NNI were equal to or slightly better than those with crop N content. These optical sensor measurements provided (i) estimation of crop N content in the range 1.5–4.5%, and (ii) an assessment of whether crop N content was sufficient or excessive for optimal crop growth for NNI ranges of 0.8–2.0. Composite equations that integrated the relationships between successive measurements with the optical sensors and crop N content or NNI for periods of ≥2 weeks (often 2–3 weeks) were derived for most indices/parameters. Overall, these results demonstrated the potential for the use of these optical sensor measurements for on-farm monitoring of crop N status in muskmelon.     

Attractiveness of three weed species to polyphagous predators and their influence on aphid populations in adjacent lettuce cultivations

The utilization of olfactory responses of predators and ­parasitoids to the allelochemicals emitted by phytophagous arthropods and their host plants is becoming more important in biological pest control. The effects of three weed ­species, i.e. wormwood Artemisia vulgaris L., tansy Tanacetum vulgare L. and stinging nettle Urtica dioica L., which were planted as accompanying vegetations into a lettuce field, were examined for the predatory species Coccinella septempunctata L., Adalia bipunctata (L.), Propylea quatuordecimpunctata (L.) (Coleoptera, Coccinellidae) and Chrysoperla carnea (Steph.) (Neuroptera, Chrysopidae), as well as for aphids during the summer of 2000. The presence of weeds significantly increased the density of adults and larvae of the predators on the lettuce plants in relation to the control (lettuce field without weeds). However, the differences remained smaller for eggs and pupae. C. septempunctata tended to be the most abundant species, followed by P. quatuordecimpunctata. Remarkable differences among the attractiveness levels of the weeds in the 3 treatments were not observed. The increased populations of predators were accompanied by significantly reduced infestation rates with aphids in the treatments in relation to the control. Myzus persicae Sulzer was in general the most abundant aphid species followed by Nasonovia ribisnigri Mosley and Macrosiphum euphorbiae Thomas. The results of the present study are discussed with respect to the management of agroecosystems and the use of weeds in biological control.