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91.
Summary. The cabbage root fly possesses highly specialised and extremely sensitive receptors for “CIF”, a group of compounds present
on cabbage leaves in very small amounts, and the strongest oviposition stimulants known. Here we present evidence that the
same receptors are sensitive to a methanol extract of cabbage root fly eggs, which may contain the fly's host marking pheromone.
Based on these results, the possible role of CIF in cabbage root fly behaviour and in cabbage plants is discussed.
Received 4 April 2001; accepted 24 September 2001. 相似文献
92.
Summary. To gain insight into the evolution of the sex pheromone communication system in Ostrinia (Lepidoptera Pyralidae), the sex pheromone of the burdock borer, O. zealis was analyzed by means of gas chromatography-electroantennographic detection (GC-EAD), GC-mass spectrometry and a series of
bioassays. Four EAD-active compounds were detected in the female sex pheromone gland extract, and these were identified as
tetradecyl acetate (14:OAc), (Z)-9-tetradecenyl acetate (Z9–14:OAc), (E)-11-tetradecenyl acetate (E11-14:OAc) and (Z)-11-tetradecenyl acetate (Z11-14:OAc). The average amounts (ratio) of the four compounds in single sex pheromone glands were 2.5 ng (13%), 11.6 ng (61%),
4.1 ng (21%) and 0.9 ng (5%), respectively. In a wind-tunnel bioassay, the ternary blend of Z9-, E11- and Z11-14:OAc at a ratio found in the sex pheromone gland elicited the same behavioral responses from the males as did virgin
females. 14:OAc did not show any enhancement or inhibition of the males’ behavioral responses when added to the ternary blend.
The attractiveness of the 3-component lure to O. zealis males was also confirmed by field trapping experiments. Based on these results, we concluded that the sex pheromone of O. zealis is composed of Z9-14:OAc, E11-14:OAc and Z11-14:OAc at a ratio of 70:24:6. The evolutionary changes of the sex pheromones in Ostrinia are also discussed based on the presently available information on the sex pheromones and phylogenetic relationships of Ostrinia spp.
Received 25 September 1998; accepted 2 December 1998. 相似文献
93.
Lilley Richard Hardie Jim Merritt L. A. Pickett John A. Wadhams Lester J. Woodcock Christine M. 《Chemoecology》1994,5(1):43-46
Summary The sex pheromone of the grain aphid,Sitobion avenae (Fab.), is identified as (4aS,7S,7aR)-nepetalactone, for which specific olfactory cells are located in the secondary rhinaria of the male antenna. The related (1R,4aS,7S,7aR)-nepetalactol was not produced by females in significant amounts (ca 10,000-fold less than the nepetalactone), although cells in the male antenna were found that responded specifically to this compound. Behavioural activity in the linear track ol-factometer showed attraction of males to the nepetalactone, but not to the nepetalactol. 相似文献
94.
The aphid alarm pheromone (E)-β-farnesene (EβF) is an efficient signal that warns aphids of attack by natural enemies. In this field study, eight open-top chambers (OTCs) located in Beijing, China (40°11′N, 116°24′E) with spring wheat Triticum aestivum were used to examine the response of the grain aphid Sitobion avenae to CO2 (ambient vs. double ambient) and EβF (applied zero, two, or five times each day). We experimentally tested the hypotheses that, depending on frequency of EβF release, elevated CO2 reduces the response (in terms of population density) of S. avenae to EβF, and that lower activity of acetylcholinesterase (AChE) in S. avenae may be involved in its reduced sensitivity to EβF under elevated CO2. Numbers of S. avenae declined with increased frequency of EβF application under ambient CO2 but were unaffected by EβF application under elevated CO2. Additionally, the mean relative growth rate (MRGR) and the dry material and amino acid content of S. avenae increased with elevated CO2 but declined when with EβF application. Activities of superoxide dismutase and catalase were higher in S. avenae under elevated vs. ambient CO2. Under elevated CO2, however, AChE activity remained low when S. avenae was exposed to the lower EβF frequency, while the highest AChE activity occurred in aphids exposed to the higher EβF frequency. These results indicate that aphids become insensitive to EβF under elevated CO2, perhaps because of decreased AChE activity. 相似文献
95.
Recruitment in social insects often involves not only inducing nestmates to leave the nest, but also communicating crucial
information about finding profitable food sources. Although bumblebees transmit chemosensory information (floral scent), the
transmission mechanism is unknown as mouth-to-mouth fluid transfer (as in honeybees) does not occur. Because recruiting bumblebees
release a pheromone in the nest that triggers foraging in previously inactive workers, we tested whether this pheromone helps
workers learn currently rewarding floral odours, as found in food social learning in rats. We exposed colonies to artificial
recruitment pheromone, paired with anise scent. The pheromone did not facilitate learning of floral scent. However, we found
that releasing floral scent in the air of the colony was sufficient to trigger learning and that learning performance was
improved when the chemosensory cue was provided in the nectar in honeypots; probably because it guarantees a tighter link
between scent and reward, and possibly because gustatory cues are involved in addition to olfaction. Scent learning was maximal
when anise-scented nectar was brought into the nest by demonstrator foragers, suggesting that previously unidentified cues
provided by successful foragers play an important role in nestmates learning new floral odours. 相似文献
96.
The cuticular surface of sexually mature females of the German cockroach contains a sex pheromone that, upon contact with the male's antennae, elicits a characteristic species-specific courtship behavior. This female-specific pheromone is a blend of several long-chain methyl ketones, alcohols and aldehydes, all derived from prominent cuticular hydrocarbons found in all life stages of this cockroach. We found that contact with the antennae of 5 out of 20 assayed cockroach species elicited courtship behavior in German cockroach males. The heterospecific courtship-eliciting compounds were isolated by behaviorally guided fractionation of the active crude extracts and compared to the native sex pheromone components. We identified two active compounds from the cuticular extract of the Oriental cockroach, Blatta orientalis -- 11-methylheptacosan-2-one and 27-oxo-11-methylheptacosan-2-one; the former compound was confirmed by synthesis and proved to independently stimulate courtship in German cockroach males. These compounds share common features with, but are distinct from, any of the known contact sex pheromone components. This suggests that sex pheromone reception in the male German cockroach is unusually promiscuous, accepting a wide range of compounds that share certain features with its native pheromone, thus resulting in a broad spectrum of behavioral response to other species. We propose that several characteristics of their mating system -- chiefly, absence of closely related species in the anthropogenic environment, resulting in relaxation of selection on sexual communication, and a highly male-biased operational sex ratio -- have driven males to respond with extremely low thresholds to a wide spectrum of related compounds. 相似文献