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[学术文献] A Nucleopolyhedrovirus from the Mediterranean flour moth, Ephestia kuehniella (Lepidoptera: Pyralidae) 进入全文

Applied Entomology and Zoology 期刊

In the present study, a Nucleopolyhedrovirus (NPV) was isolated from laboratory-reared larva of the Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae). Under the light microscope, high numbers of polyhedral inclusion bodies (PIBs) formed by the virus were found in hemolymph, tracheae, and the midgut. The PIBs measured 1.97 ± 0.46 (1–3.04) µm (n = 50). In cross-sections of PIBs, the virions contain a high number of nucleocapsids (1–28), and the viral particles were 190–270 × 30–40 nm. Some diamond-shaped inclusion bodies, like spindles, which did not include virions, were also observed. This virus was isolated and characterized for the first time from E. kuehniella.

[学术文献] Oviposition behavior of Dalbulus leafhoppers (Homoptera: Cicadellidae) 进入全文

Annals of the Entomological Society of America 年鉴

Oviposition behavior of seven Dalbulus species was studied in the laboratory on six-leaf stage maize, Zea mays L. The location of each egg was recorded for leaf or sheath, basal or apical half of each leaf, upper (adaxia) or lower (abaxial) leaf surface, and on or off midrib. Also determined was whether eggs were clustered or not. The leafhoppers were separated into three distinct groups: 1) D. elimatus (Ball), D. guevarai DeLong, and D. longulus, DeLong; 2) D. quinquenotatus DeLong & Nault and D. madis (DeLong & Wolcott); 3) D. tripsacoides DeLong & Nault and D.gelbus DeLong. Egg placement by Dalbulus leafhoppers is discussed in terms of their geographical distribution, habitat preference, and interspecific competition. Oviposition behavior closely agrees with a phylogeny of the genus based on morphology.

[学术文献] Ovipositional and feeding preference of leafhoppers [Empoasca fabae] (Homoptera: Cicadellidae) on Clark soybeans in relation to plant pubescence 进入全文

Journal of the Kansas Entomological Society 期刊

Ovipositional preference of the potato leafhopper, Empoasca fabae (Harris), was determined on eight isolines (pubescent types) of Clark soybeans. In field tests, counts of all leafhoppers on the isolines were used as an index of feeding preference; the glabrous and curled deciduous lines had the highest number of leafhoppers and the dense type the fewest number of leafhoppers. In greenhouse tests, the glabrous line received a significantly greater number of eggs than the other lines, but the curled deciduous line was also highly preferred for oviposition. The dense pubescent soybean line received the least number of eggs.

[前沿资讯] Tealet Exemplifies Transparency 进入全文

World Tea News 网站

Tealet is a Las Vegas-based tea wholesaler and tearoom that prioritizes transparency in its tea sourcing. Founder Elyse Petersen, who has a background as a food scientist and worked in the food industry doing product development, quality control, and FDA compliance, formed Tealet to connect tea farmers with tea businesses and makes transparency central to her business model. In 2012, she founded Tealet to import teas into the American market. Her goal is to find the biggest wholesale market for tea farmers, distributors and teahouse owners who want to buy fully transparent direct trade tea. “It’s a new concept of collaborative consumption,” said Petersen, who has met all of the farmers whose tea she imports. She feels the demand for transparency is what has bolstered her business’s success. Tealet has sold more than 800 teas, many of which are seasonal. 

[科技报告] NTP TECHNICAL REPORT ON THE TOXICOLOGY STUDIES OF GREEN TEA EXTRACT IN F344/NTac RATS AND B6C3F1/N MICE AND TOXICOLOGY AND CARCINOGENESIS STUDIES OF GREEN TEA EXTRACT IN WISTAR HAN[Crl:WI(Han)] RATS AND B6C3F1/N MICE (GAVAGE STUDIES) 进入全文

美国卫生与公众服务部

背景:从茶树叶子中提取的浓缩提取物被用作减肥的营养补充剂,并作为防晒霜和其他化妆品的成分。研究了绿茶提取物对雌雄大鼠和小鼠的影响,以确定潜在的毒性或癌症相关的危害。结果:在大鼠和小鼠中均未观察到与绿茶提取物有关的肿瘤发生率的增加。然而,在每个研究中都观察到各种各样的非癌症病变。暴露于绿茶提取物组的所有大鼠和小鼠均可见鼻部的一系列病变,包括化脓性炎症、嗅觉上皮萎缩、上皮增生和上皮化生。肝、胃、小肠坏死;心外膜(心脏)发炎;服用绿茶提取物的雄性和雌性大鼠出现肺化脓性炎症和脾脏淋巴样耗损,而服用绿茶提取物的雄性和雌性大鼠的下颌淋巴结和骨髓增生明显增加。雌性大鼠骨髓增生发生率增加,雄性大鼠肝脏炎症、造血细胞增殖发生率增加。结论:绿茶提取物对雌雄大小鼠的任何部位都不会致癌。在大鼠的鼻子、肝脏、胃、小肠、心脏、肺、骨髓和脾脏部位有非肿瘤性病变,以及在小鼠的鼻子、肝脏、下颌淋巴结和骨髓部位发生非肿瘤性病变,均与绿茶提取物有关。

[学术文献] Effects of habitat type and spatial scale on density dependent parasitism in Anagrus parasitoids of leafhopper eggs 进入全文

Biological Control 期刊

The ability of parasitoids to maintain a high rate of parasitism under varying conditions is considered crucial to their ability to control the populations of their hosts. Here, I tested parasitism rate by Anagrus parasitoids and its dependency on the density of Erythroneura leafhopper eggs at two spatial scales (leaf and field) and two habitat types (natural vs. agricultural). The rate of parasitism differed among field sites, increased across the season, and was similar in natural and agricultural sites. At the leaf scale, the rate of parasitism was density-independent or inversely density-dependent, consistent with a weak aggregation of parasitoids on leaves with high host densities and with limited oviposition-rate or egg supply. At the field scale, in contrast, parasitism rate was positively dependent on host density, which may be explained by demographic processes, such as higher recruitment and higher fecundities of females in host-rich field sites. Overall, the results demonstrate that parasitism patterns are highly dynamic in time and space and depend on the scale of observation.

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