白蜡窄吉丁(鞘翅目:吉丁甲科)的生物防治研究进展

白蜡窄吉丁Agrilus planipennis Faimaire原分布在东北亚国家,包括俄罗斯远东地区,在原产地由于为害不重而受关注度不高,因此没有被列入世界各国危险性有害生物监测重点名单之中。但自21世纪初其传入美国和加拿大之后,已造成重大灾害,成为迄今为止北美地区危害性最大和造成经济损失最为严重的外来入侵森林害虫。由于该害虫的高度隐蔽性,在传入地的早期检测非常困难,发现该虫的地点往往其种群已经定殖多年,因此根除策略难以奏效。美国在白蜡窄吉丁入侵初期进行的根除策略失败后迅速启动了生物防治计划。通过国际合作研究,美国从中国引进了3种寄生性天敌:白蜡吉丁柄腹茧蜂Spathius agrili Yang、白蜡吉丁啮小蜂Tetrastichus planipennisi Yang和白蜡吉丁卵跳小蜂Oobius agrili Zhang & Huang,经大量人工繁殖后在林间进行了释放,现已在当地成功建立了天敌种群,开始发挥越来越重要的控制作用。本文对最近10多年来白蜡窄吉丁生物防治方面的研究进展进行了回顾和简要综述,希望对我国同类蛀干害虫的研究工作有所启示。     

The tortoise and the goat: Interactions on Aldabra island

Endemic giant tortoises and introduced feral goats are the two major terrestrial herbivores on Aldabra atoll and have similar distributions. The tortoises vastly outnumber the goats, however, and the impact of the goats on the tortoises is minimal. Intraspecific competition is a much greater factor for the tortoises than interspecific competition. Feeding habits are significantly different, goats being primarily browsers and tortoises primarily grazers. Both species affect of the growth forms and regeneration of many plant species, but again due to sheer numbers, the tortoises' impact is much greater than the goats. Direct behavioural interactions between tortoises and goats are rare. Goats may, however, indirectly benefit tortoises by depositing heavy loads of faeces at coastal sleeping sites, thus acting as fertilizing agents, moving nutrients from tortoise-inaccessible to tortoise-accessible areas.     

Effects of alkaline hydrogen peroxide treatment of cotton and wheat straw on cellulose crystallinity and on composition and site and extent of disappearance of wheat straw cell wall phenolics and monosaccharides by sheep

Effects of alkaline hydrogen peroxide (AHP) treatment on cellulose crystallinity and cell wall phenolic monomer and monosaccharide composition were measured using cotton and wheat straw (WS). Two WS treatments were used in this study, Type I WS, for which pH is not regulated during AHP treatment, and Type II WS, for which pH is regulated at 11.5 +/- .2 during AHP treatment. Wheat straw had a lower degree of cellulose crystallinity than cotton, but no differences occurred between treated and untreated substrates. Alkali-labile and nitrobenzene-extractable phenolic monomer concentrations were generally lower for Type I and Type II WS compared with untreated WS. Concentrations of glucose were higher and xylose and arabinose lower in Types I and II WS than in untreated WS. Disappearance of alkali-labile phenolic monomers and cell wall monosaccharides by wethers fed diets containing Type I (Exp. 1) or Type II (Exp. 2) AHP-treated WS were determined. Apparent digestibility of glucose and xylose before the duodenum, and of glucose, xylose and arabinose in the total tract, was greatest (P less than .05) when sheep were fed AHP-treated WS diets in both experiments. In Exp. 2, disappearance of alkali-labile phenolic monomers was greatest (P less than .05) before the duodenum and in the total tract when sheep were fed AHP-treated WS diets. Treatment of WS with AHP modified cell wall composition and increased cell wall monosaccharide digestion by sheep.     

Chronic flunixin meglumine therapy in foals

Effects of a therapeutic dose of flunixin meglumine on gastric mucosa of horse foals were determined by endoscopy, double-contrast radiography, and gross and histologic examinations. Foals were administered 1.1 mg of flunixin meglumine/kg of body weight, PO/day for 30 days in an encapsulated form that was divided into 2 doses/day (group 1; n = 3) or by IM injection once a day (group 2; n = 7). Three control foals (group 3; n = 3) were administered capsules (n = 1) containing dextrose powder or IM injections (n = 2) of vehicle solution without flunixin meglumine. All 3 groups-1 foals given flunixin meglumine PO developed oral ulcers. Group-2 foals given flunixin meglumine IM did not develop oral ulcers. One control foal (group 3) developed 1 oral ulcer that healed during the study. Endoscopic examination revealed linear crease-like mucosal lesions in the glandular portion of the stomach in 2 group-2 foals. Radiographic evidence of gastric ulcers was observed in only 1 gastrogram of a group-1 foal. Foals were euthanatized, and necropsy revealed erosions and/or ulcers of the glandular portion of the stomach. Oral ulcers were observed in all 3 group-1 foals. Erosions of the glandular portion of the stomach developed in all 10 foals given flunixin meglumine, but did not develop in group-3 foals. Ulceration of the glandular portion of the stomach was present in 1 group-2 foal.     

RESPONSE OF SQUAMOUS CELL CARCINOMA OF THE NOSE OF THE CAT TO TREATMENT WITH X RAYS

Results of radiotherapy of 88 cats with squamous cell carcinomas of the nose were recorded. Two treatment regimens were used: 2000 rad per treatment at monthly intervals and 1000 rad at two-day intervals, with a total dose of 3000 rad. Results indicated that three treatments of 1000 rad each was superior to monthly treatments of 2000 rad. Small lesions had the highest cure rate. Response of large lesions to radiotherapy was poor.     

Recent advances in understanding the spectrum of canine generalised progressive retinal atrophy

Canine generalised progressive retinal atrophy (gPRA) is a large and ever-increasing collection of naturally occurring, heterogeneous, progressive disorders. Most are inherited in an autosomal recessive manner and new, breed-specific forms continue to be described. The gPRAs cause photoreceptor cell death and subsequent retinal degeneration, culminating in blindness. In humans, similar inherited retinal dystrophies are recognised as retinitis pigmentosa and macular dystrophy. Molecular biological studies have revealed disease-causing mutations in several genes in humans and also in mice with retinal dystrophies. Recently, molecular genetic techniques have identified the cause of one form of gPRA in Irish setters while important candidate genes have been investigated in other breeds. Identification of mutations responsible for different forms of gPRA allows carrier and pre-degenerate animals to be detected using DNA-based tests. Such genetic tests will greatly facilitate the eradication of these diseases in different breeds.