Einige Beobachtungen über die Flucht von adulten Lepidopteren aus den Netzen orbiteler Spinnen

Zusammenfassung Beobachtungen bei Zürich ergaben, daß Lepidopteren-Falter oft in der Lage sind, sich aus Spinnennetzen von Arten der Argiopidae und Tetragnathidae zu befreien. Lepidopteren machen nur einen sehr kleinen Teil der Nahrung dieser Spinnen aus. Diese Tatsache muß bei der Bewertung von Spinnen als Schädlingsfeinde mit berücksichtigt werden.

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Some observations on the escape of adult Lepidoptera from webs of orb-weaving spiders

Field studies near Zurich (Switzerland) have shown, that adult Lepidoptera often are able to escape from spider webs of the families Argiopidae and Tetragnathidae. In the food of these orb-weaving spiders Lepidoptera made up only a very small part. The capability of the lepidopterans to escape from spider webs seems to be of great ecological importance.

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Mit einer Tabelle

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Ausgeführt mit Unterstützung durch den schweizerischen Nationalfonds zur Förderung der Wissenschaftlichen Forschung.     

On the rearing of the aphid lion,Chrysoperla carnea Steph. (Neuroptera,Chrysopidae) on artificially paralized preys

Full-grown paralyzed larvae ofSpodoptera littoralis, Phthorimaea operculella andAnagasta kuebniella were used as preys for rearingChrysoperla canea larvae.P. operculella induced the shortest larval period, the lowest larval or pupal mortality, highest percent of emergence, longest adult longevity and maximum productivity. Using mature larvae ofS. littoralis gave intermediate values between those reported forP. operculella andA. kuebniella.     

Effect of zinc fertilization on rice plants and on the population of the rice-root nematodeHirschmanniella oryzae

The effect of different levels of zinc fertilization applied by two methods on the growth and yield of rice infected with the rice-root nematode,Hirschmanniella oryzae was assayed under the field conditions. A positive correlation between zinc concentration and both rice grain yield andH. oryzae total population was found. Only the seed-soaking method of zinc application, significantly increased the rice growth and the nematode total population density. Increasing percentages of nematode total population and growth and grain rice yield caused by the soaking method were more than those of the second one. In case of the first method the nematode total population ofH. oryzae reached the peak 60 days after transplanting and then declined thereafter as the rice plants reached maturity. While, in case of the second method, the nematode total population reached the peak 90 days after transplanting as the rice plants reached maturity.     

Über die Fähigkeit vonBracon brevicornis Wesm. (Hym., Braconidae), zwischen nicht infizierten und von Bakterien infizierten Raupen vonSesamia cretica Led. (Lep., Noctuidae) zu unterscheiden

Sesamia cretica larvae infected with the bacterium,Serratia marcescens orBacillus thuringiensis were exposed toBracon brevicornis females, separately and in combination with non-infected larvae in the laboratory. Host larvae were exposed to the parasitoid under two manipulations “the larvae still alive or dead completely”. Bracon brevicornis females could not absolutely discriminate between healthy and moribund larvae (due toB. t. orS. m.) when those larvae exposed in a live appearance separately or jointly. However, they could discriminate between dead larvae (due to parasitoid's venom) and dead larvae due to Bacteria (B. t. orS. m.).     

鸡传染性支气管炎的预防与控制

正传染性支气管炎是由传染性支气管炎病毒(IBV)引起的一种急性、高度传染性的呼吸道疾病,给禽业造成巨大的经济损失,严重影响肉鸡和蛋鸡的生产性能。传染性支气管炎这个疾病在世界各地均有发生,没有地方没有此疾病。传染性支气管炎病毒是冠状病毒,属于线性单链RNA病毒,具有高度突变的特性,有囊膜,多形态,直径为120~140nm。这个病毒上有2个非常重要的蛋白,纤凸S蛋白,这个表面凸出蛋白,已知的有2个功能,