Flower Scent of Floral Oil-Producing Lysimachia punctata as Attractant for the Oil-Bee Macropis fulvipes

Most flowers offer nectar and/or pollen as a reward for pollinators. However, some plants are known to produce mostly fatty oil in the flowers, instead of nectar. This oil is exclusively collected by specialized oil-bees, the pollinators of the oil-plants. Little is known about chemical communication in this pollination system, especially how the bees find their hosts. We collected the floral and vegetative scent emitted by oil-producing Lysimachia punctata by dynamic headspace, and identified the compounds by gas chromatography coupled to mass spectrometry. Thirty-six compounds were detected in the scent samples, several of which were flower-specific. Pentane extracts of flowers and floral oil were tested on Macropis fulvipes in a biotest. Flower and oil extracts attracted the bees, and some of the compounds identified are seldom found in the floral scent of other plants; these may have been responsible for the attraction of the bees.     

Scent-Marking in the Eurasian Beaver (Castor fiber) as a Means of Territory Defense

Beaver (Castor spp.) normally scent-mark by depositing castoreum and/or anal gland secretion on scent mounds close to the water's edge. The aim of this study was to investigate the hypothesis that the Eurasian beaver (C. fiber) scent-marks as a means of territory defense. Scent-marking behavior was studied during an entire year (April 1, 1995–March 31, 1996) in seven adjacent territories along 9.2 km of the B River in Telemark County, Norway. The number and location of fresh scent marks were recorded biweekly. The main results showed that: (1) the number of scent marks in territories was significantly higher in spring, when dispersal of subadults normally occurs than during the rest of the year; (2) the number of scent marks was clumped near territorial borders; and (3) the number of scent marks was significantly greater upstream than downstream of the lodge.     

(S)-2,3-Dihydrofarnesoic Acid, a New Component in Cephalic Glands of Male European Beewolves Philanthus triangulum

The chemical composition and functional significance of pheromones of solitary Hymenoptera is much less well known compared to social species. Males of the genus Philanthus (Sphecidae) are territorial and scent mark their territories to attract females. Because of inconsistent results of earlier studies, we reanalyzed the content of the cephalic glands of male European beewolves, Philanthus triangulum F. Besides a variety of alkanes and alkenes, four major compounds were found. Two of these, (Z)-11-eicosen-1-ol and (Z)-10-nonadecen-2-one, had been previously described as constituents of the cephalic glands. We identified 1-octadecanol as a new component of the cephalic gland, and a fourth compound, enantiopure (S)-2,3-dihydrofarnesoic acid, was identified for the first time in nature. Structural elucidation and enantiomeric analysis were performed by HRGC-MS and HRGC-FTIR as well as enantioselective gas chromatography and by means of authentic reference compounds. Occurrence and     

Response of captive male red foxes (Vulpes vulpes L.) to some conspecific odors

Captive male red foxes were allowed access to urine and anal sac secretions collected from both familiar and unfamiliar foxes of both sexes. Conspecific odors commonly elicited higher visiting and marking frequencies than did their distilled water controls. Unfamiliar odors generally attracted a higher frequency of urinations than familiar odors, and unfamiliar male urine elicited a longer investigation time and was urine-marked more frequently than other stimulus odors.     

Responses to inter- and intraspecific scent marks in pine martens (Martes martes)

In order to analyze intra and interspecific olfactory discrimination, behavioral responses (sniffing and marking) towards various odors were observed in pine martens (Manes martes). Two adult males and two adult females were tested for intraspecific discrimination of abdominal gland odors and urine. Both sexes sniffed and marked objects carrying their own scent less than unscented objects. There were no differences in sniffing or marking objects impregnated with odors from known and unknown conspecifics of the opposite sex or objects carrying the odor of an unknown male or female. A second experiment with two adult females gave no evidence for interspecific discrimination: no differences emerged when comparing reactions towards marks of pine martens, stone martens (a closely related species), or genets. The most obvious result of this study is the reduced response of pine martens towards their own mark. It is suggested that scent marking in martens may reflect autocommunication, the primary effect being to familiarize an animal with its environment.     

Responses by domestic cats (Felis catus) to snake scent gland secretions

The scent gland secretions of snakes are thought to repel predators, but few predator species have been tested for responses to these exudates. Domestic cats (Felis catus) were tested for responses to scent gland secretions of the gray rat snake (Elaphe obsoleta), or to choloroform extracts of them, applied to filter paper or food. More cats salivated or rubbed on filter papers treated with scent gland secretions than on control papers. Scent gland exudates elicited rubbing and pawing in cats more frequently than did chemicals from a shed snake skin. Cats offered food pieces treated either with water or with scent gland secretions ate fewer of the latter; this result is consistent with the hypothesis that scent gland secretions deter feeding.     

Chemical signals involved in spacing behavior of breeding female bank voles (Clethrionomys glareolus Schreber 1780, Microtidae,Rodentia)

In order to study the mechanism involved in the seasonal territoriality of breeding bank voles, the social behavior and scent marking of paired females were observed throughout a reproductive cycle. Initially unfamiliar females were kept in large laboratory pens provided with individual burrows. After a brief period of hostility, females behaved in a friendly manner towards each other, sharing the same nest even in the presence of a male and until the middle of pregnancy. They scarcely marked with urine. Continuous olfactory assessment appeared to play an important role in maintaining the friendly interactions. In late pregnant and lactating females, on the contrary, the odor of a familiar female triggered aggressiveness and scent marking with urine and probably with flank glands. These reactions may be interpreted as spacing behavior. Moreover, the interaction between females may inhibit reproduction in one of them. These results are discussed in relation with the available ecological data.     

Perineal scent gland of wild and domestic guinea pigs

Wild and domestic male guinea pigs (Cavia aperea andCavia porcellus) prefer the perineal secretion from males of the same species to that of males of the other species. Gas chromatographic-mass spectroscopic analyses of the volatile components of the secretions show complex mixtures comprised primarily of fatty acids, alcohols, and ketones. Inter-species differences in the composition of the volatiles are evident. The possible role of bacteria in odor production is discussed.Camille and Henry Dreyfus Teacher-Scholar, 1978–1983.     

碱性电弧炉冶炼含硫钢工艺试验

介绍了碱性电弧炉冶炼含硫钢的工艺特点。通过在还原期S合金化和二次造亚酸性炉渣工艺,把S的收得率提高到93％。     

CH4检测系统微弱信号处理电路研究

基于光谱吸收原理设计的CH4检测系统,气体吸收的信号比光源的噪声还要小,被淹没在背景噪声中.为改善检测系统的信噪比,针对非常微弱的气体吸收信号,基于微弱信号的锁定检测原理,以锁相放大器为核心,以同步积分器自动跟踪滤波,设计了检测系统的光电信号处理电路.结果表明电路输出电压与CH4体积分数呈线性关系,电路对CH4气体体积分数的检测极限为150×10-6.