Insecticidal potency of novel compounds on multiple insect species of medical and veterinary importance

BACKGROUND: Vector‐borne diseases continue to present significant threats to human, animal and plant health. Mosquitoes, houseflies, sand flies and stable flies are well‐known vectors of several human and animal pathogens. The toxicity of selected semiochemicals with molecular structures indicative of insecticidal activity was determined against these insect species with the aim of developing novel insecticides toxic to multiple insect species. RESULTS: Three semiochemicals, namely beta‐damascone, cyclemone A and melafleur, showed remarkable toxicity to three mosquitoes, Aedes aegypti L., Ae. albopictus (Skuse) and Anopheles quadrimaculatus Say, the housefly, Musca domestica L., the stable fly, Stomoxys calcitrans L., and the sand fly, Lutzomyia shannoni (Dyar). The chemicals were equally toxic to several field‐collected permethrin‐tolerant housefly strains. When formulated as 500 mL L^?1 emulsifiable concentrates, the chemicals demonstrated stability and toxicity on filter paper and camouflage military fabrics, with persistence up to 8 days under laboratory conditions. The chemicals were equally effective under field conditions when evaluated on unpainted plywood panels, although a higher dosage was required under field conditions to achieve similar efficacy. CONCLUSION: Laboratory quantification of LC₅₀ values and field efficacy of three semiochemicals as formulated compounds on mosquitoes, houseflies, stable flies and sand flies showed that these semiochemicals could serve as potent insecticides for multiple insect species. Copyright © 2010 Society of Chemical Industry     

Vertical Distribution of Arthropod Interactions Within Turfgrass

Arthropod predators are abundant in turfgrass systems, and they play an important role in managing pests. Understanding the vertical distribution of predation is critical to developing cultural strategies that enhance and conserve predatory services. However, little is known on how the predation is vertically distributed within the turfgrass canopy. Thus, the objective of this study was to determine the vertical distribution of predation within the turfgrass canopy. Clay models were used to emulate the general appearance of Noctuidae caterpillars, to estimate the predatory activity. The choice and no-choice experiments were conducted by placing clay models at 2.54, 5.08, and 7.62 cm from the thatch surface and denoted as lower, intermediate, and upper levels, respectively, within turfgrass canopy. The predator-mediated impressions, paired mark, scratch, deep cut mark, deep distortion, prick, dent, stacked surface impression, scooped mark, granulation, and U-shaped mark, were identified on clay models. The incidence and severity of impressions were significantly greater on clay models placed at the lower canopy level than on those placed at the intermediate and upper canopy levels in the choice and no-choice experiments (P < 0.05). Thus, predators are more likely to find their prey at the soil level. This information can be used to refine management strategies, such as mowing height and insecticide use for effectively managing soil-borne and foliar-feeding arthropod pests and beneficial arthropods.     

中国西藏小反刍兽疫的发生状况与防控

2007年7月,我国首次在西藏自治区阿里地区发生了小反刍兽疫疫病流行.从2007年7月9日到11月15日,先后在阿里地区革吉、日土、札达、改则4个县出现疫情,共20个疫点,羊发病6122只,死亡1888只.2008年6月,在那曲地区尼玛县双湖区再次发现小反刍兽疫疫情,病羊及同群羊合计6690只.为消灭该病,采取了扑杀、...     

银杏内生细菌防治辣椒疫病研究

从健康银杏植株叶片中分离到108 株内生细菌,通过平板测试从中筛选获得35 株对辣椒疫霉菌Phytophthora capsici具有拮抗作用的菌株.温室盆栽试验证明,菌株 Zy44、Fy11、Hy7、Hy14 和 Zy25 对辣椒疫病防效显著,其中Zy44 和 Fy11 发酵液在辣椒疫霉菌接种 20 d 后防效分别为 62%和 52.33%;经形态观察、生理生化特征测试、16S rDNA序列和gyrB基因序列分析,鉴定这两个菌株为解淀粉芽胞杆菌Bacillus amyloliquefaciens;其发酵滤液及酸沉淀获得的脂肽类抑菌物质对盆栽辣椒苗疫病的防治试验结果表明,菌株 Zy44 的防效高于 Fy11,且脂肽类物质的防效高于发酵滤液;显微镜观察发现菌株 Zy44的脂肽类抑菌物质可导致辣椒疫霉菌菌丝体膨大, 分枝增多, 成簇状,并显著抑制孢子囊的形成.     

CASE REPORT: Corneal papilloma associated with papillomavirus in a one‐humped camel (Camelus dromedarius)

A 15‐year‐old male dromedary camel with a history of chronic severe keratoconjunctivitis and corneal mass in the left eye of 6 months’ duration was referred to the Veterinary Medical Teaching Hospital at Adnan Menderes University. A superficial keratectomy was performed and biopsy material submitted for histopathology. The diagnosis was corneal papilloma. There has been no recurrence of the neoplasm to date (6 months, 1 year). Corneal papilloma has not been reported previously in camels and seems to be associated with papillomavirus.     

Human–Dromedary Camel Interactions and the Risk of Acquiring Zoonotic Middle East Respiratory Syndrome Coronavirus Infection

Middle East respiratory syndrome coronavirus (MERS‐CoV) cases without documented contact with another human MERS‐CoV case make up 61% (517/853) of all reported cases. These primary cases are of particular interest for understanding the source(s) and route(s) of transmission and for designing long‐term disease control measures. Dromedary camels are the only animal species for which there is convincing evidence that it is a host species for MERS‐CoV and hence a potential source of human infections. However, only a small proportion of the primary cases have reported contact with camels. Other possible sources and vehicles of infection include food‐borne transmission through consumption of unpasteurized camel milk and raw meat, medicinal use of camel urine and zoonotic transmission from other species. There are critical knowledge gaps around this new disease which can only be closed through traditional field epidemiological investigations and studies designed to test hypothesis regarding sources of infection and risk factors for disease. Since the 1960s, there has been a radical change in dromedary camel farming practices in the Arabian Peninsula with an intensification of the production and a concentration of the production around cities. It is possible that the recent intensification of camel herding in the Arabian Peninsula has increased the virus' reproductive number and attack rate in camel herds while the ‘urbanization’ of camel herding increased the frequency of zoonotic ‘spillover’ infections from camels to humans. It is reasonable to assume, although difficult to measure, that the sensitivity of public health surveillance to detect previously unknown diseases is lower in East Africa than in Saudi Arabia and that sporadic human cases may have gone undetected there.     

草甘膦防除灌草丛草场灌木的研究

用草甘膦喷洒灌草丛草场灌木和半灌木对其防除效果及再生性进行了试验观察。结果表明,施药浓度０．０５％以上时,半灌木死亡率１００％;浓度０．５％以上时,灌木死亡率８５％以上,７５ｄ后无再生植株,１２０ｄ后,浓度０．５％以上时,无再生植株,浓度０．１５和０．０５％时再生植株分别为１株和３株,占观察数的４％和１２％。     

不同种植年限苜蓿地土壤理化性状

本研究分析了半干旱区不同种植年限苜蓿(Medicago sativa)地土壤理化性状。结果表明,随着苜蓿种植年限的增加,0-100 cm土层土壤容重出现不规律的波动,苜蓿地土壤容重值整体偏大;土壤有机质随种植年限的增加而增大,随土层深度增加而显著减小(P<0.01),并且在种植5年的苜蓿地中提高最明显,在种植8年的苜蓿地中最低。各年限苜蓿地均表现出土壤有机质的“表聚性”。在一定的种植年限范围内,种植苜蓿对土壤有机质具有累积作用;土壤全氮含量随苜蓿种植年限的增长表现为先增大后减小的趋势,随土层深度的加深而逐渐减小,种植苜蓿4年时土壤全氮含量最大,8年时苜蓿地土壤全氮含量最低,并且土壤全氮含量主要集中于0-40 cm土层,全氮显著累积作用于表层土壤;土壤硝态氮随着苜蓿种植年限的增加而先增加后减小,随着土层的加深而逐渐降低,表层土壤对土壤硝态氮有累积作用,并且与苜蓿种植时间长短有显著相关性(P<0.05)。而铵态氮含量在剖面上变化不大,与苜蓿生长年限没有显著相关性(P>0.05)。今后需从栽培苜蓿草地的管理措施上深入探讨栽培苜蓿地的最佳种植和利用年限。     

Assessment of the long‐acting ivermectin formulation in sheep: Further insight into potential pharmacokinetic interactions

The aim of the current study was to evaluate the in vivo pharmacokinetic of ivermectin (IVM) after the administration of a long‐acting (LA) formulation to sheep and its impact on potential drug‐drug interactions. The work included the evaluation of the comparative plasma profiles of IVM administered at a single therapeutic dose (200 μg/kg) and as LA formulation at 630 μg/kg. Additionally, IVM was measured in different gastrointestinal tissues at 15 days posttreatment with both IVM formulations. The impact of the long‐lasting and enhanced IVM exposure on the disposition kinetics of abamectin (ABM) was also assessed. Plasma (IVM and ABM) and gastrointestinal (IVM) concentrations were analyzed by HPLC with fluorescent detection. In plasma, the calculated C_max and AUC_0‐t values of the IVM‐LA formulation were 1.47‐ and 3.35‐fold higher compared with IVM 1% formulation, respectively. The T_1/2ab and T_max collected after administration of the LA formulation were 2‐ and 3.5‐fold longer than those observed after administration of IVM 1% formulation, respectively. Significantly higher IVM concentrations were measured in the intestine mucosal tissues and luminal contents with the LA formulation, and in the liver, the increase was 7‐fold higher than conventional formulation. There was no drug interaction between IVM and ABM after the single administration of ABM at 15 days post‐administration of the IVM LA formulation. The characterization of the kinetic behavior of the LA formulation to sheep and its potential influence on drug‐drug interactions is a further contribution to the field.