9种不同杀虫剂对枣瘿蚊的防治效果研究

[目的]筛选枣瘿蚊的防治药剂.[方法]通过田间小区试验比较了9种杀虫剂对枣瘿蚊的防治效果.[结果]9种药剂对枣瘿蚊防治效果均有较长的持效期,其中240 g/L螺虫乙酯悬浮剂6 000倍稀释液、25％噻虫嗪水分散粒剂7 000倍稀释液具有较好的速效性和持效性,药后3、7、11d防效均在84％以上;1％甲维盐水剂、2.5％高效氯氟氰菊酯乳油、100 g/L乙虫腈悬浮剂、5％噻螨酮乳油、240g/L氟啶虫胺腈悬浮剂防治枣瘿蚊速效性较差,3d后药效均低于70％.[结论]防治枣瘿蚊为害嫩叶,240 g/L螺虫乙酯悬浮剂6 000倍稀释液、25％噻虫嗪水分散粒剂7 000倍稀释液、48％毒死蜱乳油1 500倍稀释液均对枣瘿蚊具有较稳定的防效.     

农药对桉树枝瘿姬小蜂幼虫的毒力测定

选取噻虫啉、吡虫啉、毒死蜱、噻虫嗪4种福建省林农广泛使用且内吸性强的药剂,采用对环境污染极小的树干注药法对桉树枝瘿姬小蜂虫瘿中的幼虫进行防治试验。结果表明,与前人采用喷雾法防治虫瘿内的幼虫相比,树干注药法防治效果更好。所选用的4种农药中,采用70%吡虫啉水分散粒剂的10倍液进行防治效果最好,施药18 d后校正死亡率达91.67％。4种药剂施药后2～10 d的桉树枝瘿姬小蜂幼虫的累积死亡率增幅都较10～20 d要大,且药剂稀释倍数越高,对幼虫的致死中时间越长。     

An Australian approach to IPM in cotton: integrating new technologies to minimise insecticide dependence

Insect pests represent a severe limitation for cotton production in many regions of the world. Key pests include several Heliothine moths, which are well adapted to exploit cropping systems associated with cotton and often evolve resistance to pesticides. While many components of IPM have been implemented, the main intervention for the management of key pests continues to be insecticides. This reliance on pesticides brings significant environmental liabilities of off-target drift, chemical residues and resistance. IPM must be founded on a thorough understanding of the ecology of pest and beneficial species and their interaction with the crop. The emerging era of insect resistant transgenic cottons offers real prospects to provide a foundation for more sustainable, economically acceptable IPM with the integration of a range of non-chemical tactics and much less reliance on pesticides.     

农药降解动力学模型的改进研究

研究构造出生物和非生物非线性影响因子函数1-a(c/ c0 ) θ,提出一种通过参数调整兼容指数衰减、线性和非线性作用等各种影响机制的自适应的农药降解非线性动力学模型,该改进模型直观且适用性广,可描述降解曲线凹凸有拐点的情形,用于预测时间间隔相同、连续施药的累积残留量及其极限值,实例应用表明其拟合精度和拟合效果明显优于其他模型     

Short- and long-term effects on soil microorganisms of two potato pesticide spraying sequences with either glufosinate or dinoseb as defoliants

Pesticides applied to potatoes in Swiss integrated farming were evaluated with respect to their cumulative effects on soil microorganisms in a study performed under controlled conditions. Potatoes were treated with a series of herbicides, fungicides and insecticides and were finally defoliated either by hand in the untreated control or with the total herbicides Basta (active ingredient glufosinate) or Super Kabrol (active ingredient dinoseb). Twenty-one and 135 days after the last pesticide application soil samples were collected and analysed for microbial biomass, activity and community level substrate utilisation (CLSU). In the short-term, cumulative pesticide side-effects on microbial biomass and microbial activities averaged 19% for the spraying sequence with glufosinate and 45% for the one with dinoseb. After 135 days these values merely returned to normal. Remarkably, only the CLSU patterns based on Biolog ecoplates showed a lasting effect. We consider this an indication of change in microbial catabolic capabilities that may be due either to induced pesticide degradation capabilities or to a change within the microbial community. Even though this method has drawbacks in comparison to molecular methods of microbial community analysis—in particular because of its culture dependence—it gives a first indication that changes in the microbial community may have occurred. The microbial community structure may then be analysed in more detail with molecular tools. As an additional tool to conventional testing of agrochemicals, microbial community analysis may help in the interpretation of pesticide side-effects and open up new possibilities for their observation.     

Density and composition of aquatic oligochaete populations in different farmers' ricefields

Summary The density and composition of ricefield oligochaete populations were estimated in 33 farmers' fields in the Philippines and related to physicochemical properties of the soils and agrochemical use. The spatial distribution of organisms and the investigative sampling strategy were determined from a high-intensity sampling in a single ricefield. Species diversity was low. The dominant species were Limnodrilus hoffmeisteri and Branchiura sowerbyi. The spatial distribution of populations was contagious and densities ranged from 0 to 35 000 m^-2 (maximum 620 kg ha^-1). Mean population density was positively correlated with soil moisture, organic matter, and the quantity of N fertilizer applied. No pesticide impacts were observed.     

Impacts of agricultural practices on aquatic oligochaete populations in ricefields

Summary The impacts of N fertilizer, pesticides and green manure on aquatic oligochaetes in irrigated ricefields were investigated in experimental plots. Populations, determined by the wet sieving of soil cores, were dominated by the Tubificidae Limnodrilus hoffmeisteri. Total densities ranged from 0 to 40 000 m^-2. Oligochaete numbers increased in response to additions of urea N. An inhibitory effect of carbofuran on oligochaete populations was observed during the first season of experimental pesticide treatments, but not during the following year. The green manure Sesbania rostrata stimulated population development more than Azolla microphylla. Populations in plots maintained as wet fallow remained low throughout the crop cycle. Population dynamics were associated with the crop cycle. Peak densities were achieved 30–50 days after transplanting.     

影响农药在土壤与沉积物上吸附作用的研究

农药是环境中重要的有机污染物之一,吸附作用是农药在土壤/沉积物环境中的重要迁移转化行为之一。从农药的性质结构、土壤/沉积物的组成、温度、pH值和共存有机化合物等几方面,阐述了上述因素对农药在土壤/沉积物上吸附作用及其机理的影响,并提出了该领域存在的问题及今后发展的方向。     

灭虫灵、杀虫威、菌毒威对宽体金线蛭的急性毒性作用

本文报道了灭虫灵、杀虫威、菌毒威三种常用农药对宽体金线蛭(Whitmania pinta)急性毒性作用结果。给出了三种药物对宽体金线蛭24h、48h、96h的半致死浓度(LC50)和安全浓度(SC)。     

中国苹果农药残留研究初报

为评估中国苹果农药残留状况，2003—2004年从主产区采集样品153个（渤海湾地区65个，西北黄土高原地区88个），检测29种农药的残留量。96.08%的样品检出农药残留，13.07%的样品农药残留超标。14种农药检测到了残留，但只有多菌灵、敌敌畏、对硫磷和倍硫磷等4种农药出现残留超标，超标率分别为6.54%、4.58%、2.61%和0.65%。分析了残留超标原因，提出了降低农药残留对策。