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181.
Summary The biology and behavior of Xylocopa virginica L. were followed in the area of Athens, Georgia (USA) from August 1973 until September 1974. Several nests were X-rayed regularly during the developmental period of the bees, and information about the life cycle and development was obtained. The bees emerge in June and stay in their nests with their sibs throughout the summer, fall, and winter, leaving only occasionally on warm days to search for nectar as food. In March and April males defend nest-side territories and mate with most females. The males die in the late spring and the females dig nests, provision them, and rear up to 8 or 9 bees in each nest. Many females live 2 years, and often 2 to 3 females are present in each nest, but only 1 works and lays eggs. Emergence of adults from pupae is nearly synchronized, irrespective of age. 相似文献
182.
Hermann Berg 《Die Naturwissenschaften》1960,47(14):320-321
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Olfactory learning may occur at different stages of insect ontogeny. In parasitoid wasps, it has been mostly shown at adult
emergence, whilst it remains controversial at pre-imaginal stages. We followed larval growth of the parasitoid wasp, Aphidius ervi Haliday, inside the host aphid, Acyrthosiphom pisum Harris, and characterised in detail the behaviour of third instar larvae. We found that just before cocoon spinning begins,
the third instar larva bites a hole through the ventral side of the mummified aphid exoskeleton. We then evaluated whether
this period of exposure to the external environment represented a sensitive stage for olfactory learning. In our first experiment,
the third instar larvae were allowed to spin their cocoon on the host plant (Vicia faba L.) surface or on a plastic plate covering the portion of the host plant exposed to the ventral opening. Recently emerged
adults of the first group showed a preference for plant volatiles in a glass Y-olfactometer, whereas no preference was found
in adults of the second group. In a second experiment, during the period in which the aphid carcass remains open or is being
sealed by cocoon spinning, third instar larvae were exposed for 24 h to either vanilla odours or water vapours as control.
In this experiment, half of the parasitoid larvae were later excised from the mummy to avoid further exposure to vanilla.
Adult parasitoids exposed to vanilla during the larval ventral opening of the mummy showed a significant preference for vanilla
odours in the olfactometer, regardless of excision from the mummy. The larval behaviour described and the results of the manipulations
performed are discussed as evidences for the acquisition of olfactory memory during the larval stage and its persistence through
metamorphosis. 相似文献
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Ulla Raab Michael Albrecht Ursula Preiss Wolfgang Völkel Ursula Schwegler Hermann Fromme 《Chemosphere》2013
The aim of the Bavarian Monitoring of Breast Milk (BAMBI) project was to examine 10 organochlorine pesticides (OPs), 3 nitro musks, 6 indicator polychlorinated biphenyls (PCBs), 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs), 12 dioxin-like PCBs (dl-PCBs) and several perfluorinated alkyl compounds in breast milk samples. A total of 516 breast milk samples were collected from seven regions in Bavaria and were analyzed by means of GC/ECD, GC/HRMS, and LC/MS-MS. 相似文献
189.
INTRODUCTION: Overexposure to noise remains a widespread and serious health hazard in the U.S. service providing and goods producing industries. Excessive noise can lead to poor verbal communication and reduce the ability to recognize warning signals. These dangerous work conditions can also cause stress and fatigue. Occupational hearing loss is a permanent illness, with no recovery currently possible. METHOD: National Institute for Occupational Safety and Health (NIOSH) has recognized Noise Induced Hearing Loss (NIHL) as one of the ten leading work-related diseases and injuries in the United States, and has emphasized its importance as one of the critical areas expressed in the National Occupational Research Agenda. RESULTS: One of the most serious noise problems in the goods producing industries is the operation of continuous mining machines during underground coal mining. In order to minimize occupational hearing loss, noise hazards are "designed out" early in the design process. NIOSH is leading a national initiative called Prevention through Design (PTD) to promote this concept. This paper describes the quiet-by-design approach of a noise control that reduced noise exposures of continuous mining machine operators by 3dB(A) using the four functional areas of PTD, namely Practice, Policy, Research, and Education. 相似文献
190.
Schaldach Rüdiger Meurer Katharina H. E. Jungkunst Hermann F. Nendel Claas Lakes Tobia Gollnow Florian Göpel Jan Boy Jens Guggenberger Georg Strey Robert Strey Simone Berger Thomas Gerold Gerhard Schönenberg Regine Böhner Jürgen Schindewolf Marcus Latynskiy Evgeny Hampf Anna Parker Phillip S. Sentelhas Paulo César 《Regional Environmental Change》2018,18(1):161-173
Regional Environmental Change - This article describes the design of a new model-based assessment framework to identify and analyse possible future trajectories of agricultural development and... 相似文献