Extended summaries pesticides group symposium natural products as a source for new agricultural chemicals

The following are extended abstracts of six of the papers presented at the above meeting and, as so presented, they are entirely the responsibility of the authors and do not reflect the views of the Editorial Board of Pesticide Science.     

Extended summaries sci pesticides group symposium management of Bemisia tabaci

The following are extended summaries based on papers presented at a meeting of the Physicochemical and Biophysical Panel of the SCI Pesticides Group, held on 25 January 1994 at the SCI, 14/15 Belgrave Square, London SWIX 8PS, UK. The summaries published here are entirely the responsibility of the authors and do not reflect the views of the Editorial Board of Pesticide Science.     

Methods of analysis of dithiocarbamate pesticides: a review

This review incorporates a brief introduction to methods for the analysis of dithiocarbamate pesticides followed by a more detailed discussion of individual methods. Determination of dithiocarbamate residues from foodstuffs, water and commercial samples and in various environmental samples using different techniques is a key feature. © 1999 Society of Chemical Industry     

5种药剂对入侵新害虫扶桑绵粉蚧的防治效果

扶桑绵粉蚧作为一种新的入侵害虫,具有潜在危害性,国内尚无科学的防控技术,为了科学防控此害虫,选择5种常用药剂进行防治效果研究,结果表明:40%劲克介EC、40%氧化乐果EC和48%乐斯本EC都是比较理想防治药剂。     

Studies on a new group of biodegradable surfactants for glyphosate

The effectiveness of a homologous series of biodegradable rapeseed oil derivatives (triglyceride ethoxylates; Agnique RSO series containing an average of 5, 10, 30 and 60 units of ethylene oxide (EO) as adjuvants for foliage-applied, water-soluble, systemic active ingredients was evaluated employing glyphosate as an example. Previous experiments had revealed that the surfactants used are not phytotoxic at concentrations ranging from 1 to 10 g litre-1. The experiments were performed using Phaseolus vulgaris L and nine selected weed species, grown in a growth chamber at 25/20 (+/- 2) degrees C day/night temperature and 40/70 (+/- 10)% relative humidity. The surfactants were evaluated for enhancement of spray retention, and foliar penetration biological efficacy of glyphosate. Glyphosate was applied at a concentration of 43 mM. The surfactants were added at concentrations of 1 g litre-1. The commercial glyphosate 360 g AE litre-1 SL Roundup Ultra and unformulated glyphosate served as references. The surfactants used improved spray retention, foliar penetration and biological efficacy. Some of the formulations were comparable to the performance of Roundup Ultra in the aspects evaluated; some were even more effective in enhancing spray liquid retention and promoting glyphosate phytotoxicity in several plant species. In these studies Agnique RSO 60 generally was most effective.     

Extended summary SCI pesticides group/BCPC international symposium comparing glasshouse and field pesticide performance. Comparing glasshouse and field performance of pesticides: An appraisal

The following is an extended summary based on a concluding paper presented at the above symposium, which was organised by G. Hewitt, D. Tyson, L. C. Copping, B. T. Grayson and J. C. Caseley on behalf of the British Crop Protection Council and the SCI Pesticides Group, and held at the University of Kent, Canterbury, on 12–14 April 1994. The summary is entirely the responsibility of the author, and does not necessarily reflect the views of the Editorial Board of Pesticide Science.     

Vertebrate wildlife incidents with pesticides: a european survey

A survey was carried out to investigate terrestrial wildlife incidents with pesticides in 18 European countries over the period 1990–1994. Only in seven countries does a systematic incident registration system exist. Compared with the other countries, relatively high numbers of incidents were registered in France, the Netherlands and the United Kingdom. Over 1000 incidents were investigated to establish their causes: approved use, misuse or deliberate abuse, and the compounds, species and mode of application involved. It was found that most registered incidents are due to deliberate abuse. Approved use is responsible for only a minor fraction of the incidents, and these are due to particular practices such as use of treated seed, bait or wood preservatives and the spraying of grassland. Hardly any incidents were due to crop-spraying. The reason why so few incidents are registered for normal crop-spraying is discussed: do they not occur, or are the casualties not registered? It is doubtful whether incident registration is a reliable instrument for obtaining a proper understanding of the occurrence of the side-effects of agricultural pesticide use. © 1999 Society of Chemical Industry     

Extended summary agriculture and bio-organic groups of the RSC and the SCI pesticides group symposium chemical aspects of biological control. The production of chemicals by biological control agents

The following extended summary is based on a paper presented at the above meeting organised by R. L. Richards and L. G. Copping on behalf of the Agriculture and Bio-organic Groups of the RSC and the SCI Pesticide Group, held on 21 November 1994 at Brighton, UK. The summary published here is entirely the responsibility of the author and does not reflect the views of the Editorial Board of Pesticide Science.     

小麦秆腐赤霉病药剂防治新技术田间试验

<正>小麦赤霉病是由禾谷镰孢菌(Fusarium graminearum)引起的世界性小麦重要病害,不但影响小麦产量,而且降低小麦品质。该病在大丰地区主要侵染穗部,症状是穗腐,小麦秆腐很少发生,症     

Effect of seven new orchard pesticides on Galendromus occidentalis in laboratory studies

BACKGROUND: Biological control of phytophagous mites in orchards requires that pesticides used to manage other arthropod pests or diseases are harmless to predacious mites, as these are essential to keep phytophagous mites at non‐injurious population levels. This study evaluates the possible toxic attributes of acetamiprid, imidacloprid, thiacloprid, thiamethoxam, spirodiclofen, spinosad and methoxyfenoxide currently used in western Canadian orchards. RESULTS: None of these pesticides has any ovicidal properties against Galendromus occidentalis (Nesbitt). Imidacloprid and acetamiprid were highly toxic to the adults and reduced fecundity significantly. Thiamethoxam and spirodiclofen were non‐toxic to adults, but they slightly reduced fecundity. Thiacloprid, spinosad and methoxyfenoxide were harmless to adults and had no effect on fecundity. All compounds showed some repellence at 24 h intervals for 72 h. CONCLUSIONS: Imidacloprid and acetamiprid are incompatible with IPM programs because they are toxic to adults and negatively affect fecundity. Thiamethoxam and spirodiclofen need further field evaluation to determine if they are compatible with IPM programs because they slightly reduced fecundity. Thiacloprid, spinosad and methoxyfenoxide are harmless to adults, but they are slightly repellent. Therefore, with the exception of imidacloprid and acetamiprid, all these compounds should be field tested for compatibility in an IPM program. © Her Majesty the Queen in Right of Canada, as represented by the Minister of Agriculture and Agri‐Food Canada. Published by John Wiley & Sons, Ltd     

Influence of Atrazine and Roundup pesticides on biochemical and molecular aspects of Biomphalaria alexandrina snails

The excessive use of pesticides in agriculture has sparkled the interest of scientists in investigating the harmful effects of these compounds. The present study evaluates the pesticides Atrazine and Roundup (glyphosate) on biochemical and molecular aspects of Biomphalaria alexandrina snails. The results showed that LC₁₀ of these two pesticides caused considerable reduction in survival rates and egg production of treated snails. Additionally, Atrazine proved to be more toxic to B. alexandrina snails than Roundup. In treated snails, glucose concentration (GL) in the hemolymph as well as lactate (LT) and free amino acid (FAA) in soft tissues of treated snails increased while glycogen (GN), pyruvate (PV), total protein (TP), nucleic acids (DNA and RNA) levels in snail’s tissues decreased. The activities of glycogen phosphorylase (GP), superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR), succinic dehydrogenase (SDH), acetylcholinesterase (AChE), lactic dehydrogenase (LDH) and phosphatases (ACP and ALP) enzymes in homogenate of snail’s tissues were reduced in response to the treatment with the two pesticides while lipid peroxide (LP) and transaminases (GOT and GPT) activity increased (P < 0.001). The changes in the number, position and intensity of DNA bands induced by pesticides may be attributed to the fact that pesticide can induce genotoxicity through DNA damage. It was concluded that the pollution of the aquatic environment by Atrazine and Roundup pesticides, would adversely affect the metabolism of the B. alexandrina snails, and have adverse effects on its reproduction.     

2-arylalkanoates,a new group of synthetic pyrethroid esters not containing cyclopropanecarboxylates

Although structure modifications of natural pyrethrin constituents have disclosed a variety of potent synthetic analogues, all known examples are cyclopropanecarboxylate esters, a grouping that appeared to be essential for insecticidal activity. Some new substituted 2-phenylalkanoates, whose biological activities are of a similar nature and potency to those of conventional pyrethroids, are now reported. 5-Benzyl-3-furylmethyl and 3-phenoxybenzyl 3-methyl-2-phenylbutyrates and their analogues are potent insecticides. Activity is increased on the introduction of appropriate groups into the 3 and/or 4-positions of the aryl ring and the (S)-2-phenylalkanoates are far more active than their (R)-enantiomorphs. Structure/activity relationships are compared with those for conventional pyrethroids. Some of the new series compare favourably with typical insecticides in tests against Musca domestica, Spodoptera litura and Plutella xylostella.     

2-Trichloromethylbenzimidazole,a new selective chromogenic reagent for detection of some heteroaromatic pesticides on thin-layer chromatographic plates

A highly selective method for the detection of several pesticides containing a heteroaromatic ring in the molecule (e.g. nicotine, pyrifenox or prochloraz) on thin-layer chromatographic (TLC) plates is described. The necessary detection condition is the presence in the ring of at least one tertiary nitrogen atom without substitutents on the two adjacent carbon atoms and, in the case of azoles, the protection of a secondary NH group by an alkyl or acyl group. The detection is realized by spraying the developed chromatogram with an acetone solution of 2-trichloromethylbenzimidazole and subsequently heating at 100-150°C in a drier. The detection limit is 20 ng to 10 μg depending on the detected compound. Some pesticide formulations may be analyzed using this method.     

新型生物源农药与化学农药对草莓叶螨的防效对比研究

草莓叶螨是影响北京地区草莓生产的重要害螨,本文对其进行了两种新型生物源农药(藜芦碱、多杀霉素)及化学农药(高效氯氟氰菊酯、联苯菊酯)的防效对比研究。室内毒力测定结果表明:2.5%高效氯氟氰菊酯EC和0.5%藜芦碱SL对朱砂叶螨毒力最高,其LC_(50)分别为2.54mg/L和4.18mg/L;其次是10%联苯菊酯EC和2.5%多杀霉素SC,其LC_(50)分别为13.16mg/L和84.51mg/L。田间试验结果表明:2.5%高效氯氟氰菊酯EC和0.5%藜芦碱SL对草莓叶螨防控效果最好,施药7d后防治效果达80%以上,施药14d后防治效果达82%左右,施药28d后防治效果达84%左右,持效期较长。10%联苯菊酯EC和2.5%多杀霉SC素防控效果欠佳,施药7d后的防治效果为50%左右,具有一定的防治效果;但施药14、21及28d后害虫总数有增长趋势,未表现出持续的抑制效果。与对照区相比,各药剂均表现出对草莓叶螨具有一定的防控作用。高浓度2.5%高效氯氟氰菊酯EC对草莓叶片有轻微药害,在生产中要严格控制其使用剂量;0.5%藜芦碱SL试验处理未对草莓及非靶标生物产生不良影响,安全无药害且防治效果好,在实际生产中具有良好的推广应用价值。     

我国病毒杀虫剂研究与应用新进展

由于化学农药的大量使用对环境生态造成的严重影响，我国政府已把保护环境、食品安全摆到了重要的议事日程。昆虫病毒杀虫剂作为生物防治的重要手段之一，其优点在于特异性强、毒力高、稳定性好、安全无害，用后能引起害虫群体病毒疾病的流行传播，在相当长时间内可自然控制害虫消长，导致相继世代害虫持续带毒，感染死亡。与其他化学农药和其他生物农药相比，作为生物杀虫剂，最大的优势还在于病毒杀虫剂目前未发现抗性问题，这就为病毒杀虫剂当今的发展带来了良好的契机。１重组病毒杀虫剂昆虫病毒作为生物杀虫剂具有毒力高、无抗性，用后…     

Extended summaries pesticides group symposium physicochemical properties as factors affecting the penetration of xenobiotics to the target site

Allyl alcohol esters (propionate, formate, and acetate) and structurally related compounds (3-methylallyl alcohol and vinyl acetate) were evaluated for their fumigation properties vis-a-vis Theba pisana (Mueller) snails. The esters were very effective in exterminating the snails, although less so than the parent alcohol. These results suggest that the esters might first have to undergo hydrolysis, and only thereafter demonstrate their potency. 3-Methylallyl alcohol (four-carbon member) and vinyl acetate (two-carbon member, after hydrolysis) were significantly less potent than the allyl esters. All three esters showed less phytotoxicity towards roses than did allyl alcohol itself. However, only allyl acetate caused no damage whatsoever to the entire plant tested (flower, leaves, sepals, and stem).     

Extended summaries sci pesticides group symposium biological control: Use of living organisms in the management of invertebrate pests,pathogens and weeds.

The following are extended summaries based on material presented at a meeting of the SCI Pesticides Group, held on 19-20 October 1992 at the SCI, 14/15 Belgrave Square, London SWIX 8PS, UK. The summaries published here are entirely the responsibility of the authors and do not necessarily reflect the views of the Editorial Board of Pesticide Science.