6种药剂防治福寿螺效果试验研究

通过对6种常用杀螺药剂室内药效比较试验,了解常用杀螺剂的灭螺效果。【方法】采集稻田和菜地排水沟中自然繁殖的福寿螺,选用6％劈螺斩颗粒剂,6％密达颗粒剂,65％螺消可溶粉剂,50％杀螺胺乙醇胺盐可湿性粉剂,生石灰,茶麸6种药剂,采用室内药效试验方法进行防治实验。【结果】参试农药对福寿螺都有一定的防治效果,但防治效果有较大...     

Metal chelate molluscicides: The redistribution of iron diazaalkanolates from the gut lumen of the slug,Deroceras reticulatum (Müller) (Pulmonata: Limacidae)

Two related iron chelates, one toxic to slugs by ingestion, the other not, were introduced into the foregut of D. reticulatum. The subsequent movement and redistribution of the metal within the slug tissues was studied by labelling the chelates with the radioactive isotope ⁵⁵Fe. In slugs which survived treatment approximately half of the ⁵⁵Fe was voided in faeces. The iron retained became unevenly distributed, the highest concentration occurring in the digestive gland, irrespective of the chelate used. At high doses, slugs treated with tris(1-oxo-1,2-diazabutan-2-oxido)Fe(III) were fatally poisoned while those treated with the homologue, tris(1-oxo-1,2-diazaoctan-2-oxido)Fe(III) were not. Slugs killed by the toxic chelate consistently contained proportionally less iron in the digestive gland and proportionally more in the body wall and reproductive system. Dosing slugs already killed by carbon dioxide asphyxiation gave a similar pattern, suggesting that the greater mobility of the iron from the toxic chelate was not a function of the slugs' metabolism.     

4种药剂对海南兰花蜗牛和蛞蝓的防治效果

通过筛选适用于海南热带兰园防治有害蜗牛和蛞蝓的最佳药剂及合理用量,为生产实践应用提供理论依据。选择了国内常用的4种杀软体动物剂,即50%杀螺胺乙醇胺盐可湿性粉剂、45%三苯基乙酸锡可湿性粉剂、6%四聚乙醛颗粒剂和10%茶枯精粉粉剂,针对海南兰园有害软体动物的主要优势种,包括海南小囊螺、细钻螺和双线嗜粘液蛞蝓,通过在室内模拟田间兰花栽培条件,开展了不同药剂、不同剂量的防治效果对比试验。结果显示,防治海南小囊螺效果最好的药剂是6%四聚乙醛和10%茶枯精粉,药后7 d防效达87%以上,14 d防效达100%。对细钻螺防效最好的药剂是6%四聚乙醛,药后7 d防效达83%以上,14 d防效达100%。双线嗜粘液蛞蝓对10%茶枯精粉极为敏感,药后3 d防效即达91%以上,药后5 d达到100%;另外3种均不理想。综合考虑防效与安全性,在海南热带设施栽培中防控有害蜗牛和蛞蝓,推荐同时使用6%四聚乙醛颗粒剂和10%茶枯精粉粉剂,用量每亩分别为500和1000 g。具体施药方法和效果还需大田试验进一步验证。     

40种植物甲醇提取物的杀螺活性研究

对40种药用或有毒植物甲醇提取物的室内杀螺活性测定结果表明:木荷、黄姜、博落回等3种植物提取物在浓度为100mg/L时,浸杀福寿螺幼螺48h,死亡率为100%;50mg/L时,浸杀72h,死亡率为98.28%以上。其中木荷、博落回对福寿螺有良好的抑制上爬作用,具有进一步研究价值。     

Detection of iron in tissues from slugs (deroceras reticulatum müller) after ingestion of iron chelates,by means of energy-filtering transmission electron microscopy (EFTEM)

Two iron chelates, one toxic (iron ‘butan’) and the other not (iron ‘octan’), were ingested by slugs (Deroceras reticulatum) at either a low (5 g kg⁻¹ diet) or a high (100 g kg⁻¹ diet) dose rate. In tissue sections of the digestive gland and body wall, iron was detected by energy-filtering transmission electron microscopy (EFTEM), using electron spectroscopical imaging (ESI) and electron energy-loss spectroscopy (EELS). The strongest signals for iron were obtained in secondary lysosomes of the resorptive cells in the digestive gland of slugs treated with a low dose of either compound, or with the high dose of iron ‘octan’. At the cell apices of these cells, in endocytotic vesicles and in apically located lysosomes, iron was detected only in slugs fed with either dose of iron ‘octan’. In slugs fed with the high dose of iron ‘butan’, iron could clearly be localised in the epithelial and mucus cells of the skin. The results are discussed with respect to differences in the toxicity of the two iron chelates. © 1999 Society of Chemical Industry     

The use of piperonyl butoxide and MGK-264 to improve the efficacy of some plant-derived molluscicides

Synergism of an oil of Azadirachta indica, a powdered extract of Allium sativum bulbs and an oleoresin of Zingiber officinale rhizomes by piperonyl butoxide and MGK-264 was studied against the snails Lymnaea acuminata and Indoplanorbis exustus. The active components of these plant-derived molluscicides, respectively azadirachtin, allicin and [6]gingerol, were also combined with these synergists. Both piperonyl butoxide and MGK-264 enhanced the toxicity of all of the test compounds. The response of snails to the synergised mixtures was both time- and dose-dependent. © 1998 Society of Chemical Industry     

Algal-Derived Halogenated Sesquiterpenes from Laurencia dendroidea as Lead Compounds in Schistosomiasis Environmental Control

Schistosomiasis has been controlled for more than 40 years with a single drug, praziquantel, and only one molluscicide, niclosamide, raising concern of the possibility of the emergence of resistant strains. However, the molecular targets for both agents are thus far unknown. Consequently, the search for lead compounds from natural sources has been encouraged due to their diverse structure and function. Our search for natural compounds with potential use in schistosomiasis control led to the identification of an algal species, Laurencia dendroidea, whose extracts demonstrated significant activity toward both Schistosoma mansoni parasites and their intermediate host snails Biomphalaria glabrata. In the present study, three seaweed-derived halogenated sesquiterpenes, (−)-elatol, rogiolol, and obtusol are proposed as potential lead compounds for the development of anthelminthic drugs for the treatment of and pesticides for the environmental control of schistosomiasis. The three compounds were screened for their antischistosomal and molluscicidal activities. The screening revealed that rogiolol exhibits significant activity toward the survival of adult worms, and that all three compounds showed activity against S. mansoni cercariae and B. glabrata embryos. Biomonitored fractioning of L. dendroidea extracts indicated elatol as the most active compound toward cercariae larvae and snail embryos.     

Intussusception following methiocarb toxicity in three dogs

Objective: To report intussusception as a complication of methiocarb toxicity in dogs and discuss possible risk factors. Series summary: Intestinal intussusception was diagnosed from 24 hours to 18 days following symptomatic treatment of methiocarb toxicity in three dogs. All cases had persistent clinical signs of methiocarb toxicity despite initial treatment and attempts to eliminate residual toxin. Cases 1 and 3 recovered uneventfully following supportive care, enterectomy of the affected bowel and end‐to‐end anastamosis. All dogs were <8 months of age. New information provided: Details of three cases of methiocarb toxicity that later developed intussusception and possible risk factors in these cases.