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31.
Newborn rabbits rely on odour cues to localize and seize maternal nipples. In particular, they orally respond to the mammary
pheromone (MP) emitted in rabbit milk. The activity of the MP was so far mainly investigated in newborns, and a drop in its
releasing effect was shown in 23-day old pups. Here, we evaluated the activity of the MP in a large sample (n=1588) of domestic
rabbit pups tested between birth and weaning. We also assessed whether wild-type pups respond to the MP, and whether the developmental
course of their responsiveness matches the one of domestic pups. During the first postnatal week, the MP revealed to be a
strong releasing stimulus in all pups, regardless of their genetic and environmental background. However, the saliency of
the MP decreased with approaching weaning, and this decrease was clearly steeper in wild-type than in domestic pups. These
results are discussed with regard to the concept of ontogenetic adaptation and the effects of artificial selection. 相似文献
32.
沈阳市2001年-2006年生态足迹分析与可持续发展 总被引:1,自引:0,他引:1
生态足迹从具体的生物量角度研究自然资本消耗的空间,为核算地区资本利用状况提供框架,进而可判断区域可持续发展状态。文章在简要介绍生态足迹的概念与计算模型基础上,定量研究了沈阳市2001年-2006年六年间的生态足迹和生态承载力的变化规律和特征,根据计算进行分析,结果表明人类负荷超过其生态容量,生态承载严重不能满足生态足迹的需求,社会经济处于一种不可持续的发展状态,为使沈阳市的生态建设可持续的发展提出生态恢复措施。 相似文献
33.
Suppression pheromone and cockroach rank formation 总被引:1,自引:0,他引:1
Although agonistic behaviors in the male lobster cockroach (Nauphoeta cinerea) are well known, the formation of an unstable hierarchy has long been a puzzle. In this study, we investigate how the unstable
dominance hierarchy in N. cinerea is maintained via a pheromone signaling system. In agonistic interactions, aggressive posture (AP) is an important behavioral
index of aggression. This study showed that, during the formation of a governing hierarchy, thousands of nanograms of 3-hydroxy-2-butanone
(3H-2B) were released by the AP-adopting dominant in the first encounter fight, then during the early domination period and
that this release of 3H-2B was related to rank maintenance, but not to rank establishment. For rank maintenance, 3H-2B functioned
as a suppression pheromone, which suppressed the fighting capability of rivals and kept them in a submissive state. During
the period of rank maintenance, as the dominant male gradually decreased his 3H-2B release, the fighting ability of the subordinate
gradually developed, as shown by the increasing odds of a subordinate adopting an AP (OSAP). The OSAP was negatively correlated
with the amount of 3H-2B released by the dominant and positively correlated with the number of domination days. The same OSAP
could be achieved earlier by reducing the amount of 3H-2B released by the dominant indicates that whether the subordinate
adopts an offensive strategy depends on what the dominant is doing. 相似文献
34.
Summary. Male obliquebanded leafrollers, Choristoneura rosaceana (Harris), were induced to respond to a pheromone source tainted with a behavioural antagonist, Z9-tetradecenyl acetate, when a source releasing the antagonist was placed 10 cm upwind of the tainted source in a wind tunnel.
However, placement of the antagonist upwind of an attractive pheromone source did not interrupt pheromone-mediated responses.
Placement of a source releasing Z9-tetradecenyl acetate, a minor pheromone component of the sympatric species, the threelined leafroller, Pandemis limitata (Robinson), upwind of a calling P. limitata female, reduced conspecific male pheromone-mediated response but resulted in upwind flight by male C. rosaceana and contact with heterospecific females. Male P. limitata locked on and flew upwind to but did not contact heterospecific females when a source releasing Z9-tetradecenyl acetate was positioned upwind of a calling C. rosaceana female. In the field, adaptation or habituation to Z9-tetradecenyl acetate caused by atmospheric treatment with this compound apparently resulted in reciprocal heterospecific
pheromone responses. More C. rosaceana males were captured in traps baited with their pheromone and the behavioural antagonist in small field plots treated atmospherically
with Z9-tetradecenyl acetate than in nontreated control plots. Fewer male P. limitata were captured in traps baited with their own pheromone, or with C. rosaceana pheromone tainted with Z9-tetradecenyl acetate in plots treated atmospherically with Z9-tetradecenyl acetate than in nontreated control plots. We argue that Z9-tetradecenyl acetate is an important synomone which assists in partitioning the sexual chemical communication channels of
C. rosaceana and P. limitata.
Received 9 February 1999; accepted 22 March 1999. 相似文献
35.
Summary.
Darna bradleyi Holloway, D. trima Moore, Setothosea asigna van Eecke and Setora nitens Walker are sympatric and coseasonal limacodid moths in plantations of oil palm, Elaeis guineensis Jacq. (Arecales: Palmae), in Borneo, southeast Asia. We tested the hypothesis that these four species maintain reproductive
isolation through specificity in diel periods of communication, microlocation for communication and/or communication signal
(pheromone). Studying diel periodicity of calling behavior by female moths and response by male moths to traps baited with
virgin females or synthetic pheromone, we determined that sexual communication of D. bradleyi and D. trima took place from ˜17:30 to 18:45 hr and that of S. asigna and S. nitens from ˜18:45 to 20:00 hr and from ˜18:30 to 19:30 hr, respectively. Over 80% of male S. asigna and S. nitens were captured in pheromone-baited traps suspended >5 m high, whereas male D. bradleyi and D. trima were captured mostly in traps <5 m high. Synthetic pheromone baits attracted male moths in a species-specific manner. Moreover,
baits containing both S. asigna and S. nitens pheromones failed to attract any male moths, indicating that female S. asigna and S. nitens, with overlapping communication periods, use bifunctional pheromone components that attract conspecific males while repelling
heterospecifics. Similarly, addition of D. bradleyi pheromone to S. asigna or S. nitens pheromone reduced attraction of male S. asigna and S. nitens. The failure of D. bradleyi and D. trima, which overlap in time and microlocation for communication, to evolve bifunctional pheromones may be attributed to the recent
occurrence of sympatry between D. bradleyi and D. trima in Borneo, apparently too recent for bifunctional pheromones to have evolved. We conclude that D. bradleyi, D. trima, S. asigna and S. nitens utilize any or all of diel periodicity, intra and interspecific effects of communication signal and/or microlocation for
signaling, allowing these limacodids to co-inhabit the same habitat and remain reproductively isolated.
Received 5 May 2000; accepted 18 August 2000 相似文献
36.
Summary. Young larvae of Adalia bipunctata search an area more intensively when exposed to the odour from other larvae feeding on aphids than when exposed only to the
odour of aphids. In an olfactometer young larvae were significantly attracted either to the odour of crushed aphids or larvae
feeding on aphids, but not to that of aphids, larvae, larvae plus aphids or larvae feeding on an artificial diet. That is,
the change in searching behaviour appears in response to a volatile released by aphids when attacked. The odour released by
crushed aphids is made up entirely of aphid alarm pheromone, β-farnesene. It is likely that the adaptive significance of this
response is that it increases the ability of larvae to locate larvae that have already caught prey. By sharing the aphid kill
of another larva it is likely that a first instar ladybird larva greatly increases its probability of surviving to the next
instar. It is suggested that this social feeding is facilitated by egg clustering, which also may additionally account for
why aphidophagous ladybirds lay their eggs in clusters.
Received 28 February 2000; accepted 24 March 2000 相似文献
37.
Little has been done to compare the relative importance of various mechanisms through which prey assess the potential risk
from natural enemies. We used predator-naive spider mites (Tetranychus urticae, Tetranychidae) to (1) compare the responses of prey to chemical cues from enemy and non-enemy species and (2) investigate
the source of these cues. In the laboratory, we observed the distribution of T. urticae in response to cues from nine mite species, including (1) predators of spider mites, (2) predators/parasites of other animals,
and (3) fungivores/pollen-feeders. When given a choice over 24 h, spider mites foraged and oviposited in fewer numbers on
leaf discs that were previously exposed to predatory or parasitic mites (including species incapable of attacking spider mites)
than on clean leaf discs (unexposed to mites). Interestingly, previous exposure of leaf arenas to fungivores and pollen-feeders
had no significant effect on spider mite distribution. We then observed the response of T. urticae to cues from two species of predator that had been reared on a diet of either spider mites or pollen. T. urticae showed stronger avoidance of leaf discs that were previously exposed to spider-mite-fed predators than of discs exposed to
pollen-fed predators. Nevertheless, for one predator species (Amblyseius andersoni), T. urticae still preferred to forage and oviposit on clean (unexposed) discs than on discs exposed to pollen-fed predators. Protein-derived
metabolic wastes of predatory or parasitic mites may provide a general cue about potential predation risk for T. urticae. However, T. urticae also avoided areas exposed to pollen-fed predators, suggesting there may be other sources of enemy recognition by the spider
mites. We discuss the ecological and evolutionary mechanisms that may influence the scope of information through which animals
assess predation risk.
Received: 11 January 1999 / Received in revised form: 25 October 1999 / Accepted: 20 November 1999 相似文献
38.
Summary. We tested the hypothesis that aggregation behaviour of the
firebrat, Thermobia domestica (Packard) (Thysanura: Lepismatidae), an
inhabitant of enclosed microhabitats, is mediated, at least in part, by
a pheromone. Individual insects were released into the central chamber
of a 3-chambered olfactometer and test stimuli were placed in lateral
chambers. Paper discs previously exposed for 3 days to 10 female, male,
or juvenile T. domestica were all preferred by female, male, or juvenile
T. domestica over unexposed paper discs, indicating the presence of an
aggregation/arrestment pheromone. In additional experiments, frass and
scales from female T. domestica, tested singly and in combination,
proved not to be the source of the pheromone. Physical contact was
required for pheromone recognition, indicating that the pheromone
arrests rather than attracts conspecifics. Arrestment by the
long-tailed silverfish, Ctenolepisma longicaudata Escherich
(Thysanura: Lepismatidae), but not by the common silverfish, Lepisma
saccharina L. (Thysanura: Lepismatidae), to T. domestica exposed
paper discs suggests closer phylogenetic relatedness between C.
longicaudata and T. domestica, than between C.
longicaudata and L. saccharina. Whether C.
longicaudata or L. saccharina produce an aggregation
signal, and whether T. domestica respond to this signal is unknown.
Received 10 June 2002; accepted 30 September 2002. 相似文献
39.
Summary. Lactating rabbit females emit volatile odour cues that trigger specialized motor actions leading to sucking. But the activity
of these cues may change with advancing lactation. Here, we tested this possibility in three experiments. In Exp. 1, we assessed
whether 2-day-old pups respond differently to the odour of milk from females in early (day 2) as compared to late (day 23)
lactation. In Exp. 2, a compound bearing pheromonal properties, the Mammary Pheromone (MP), was dosed in these milks to assess
whether its concentration is correlated with behavioural activity. In Exp. 3, the responsiveness to a constant level of MP
was compared in d2 versus d23-pups. Run on 240 pups, the assays showed that a) the milk activity declines between d2 and d23
of lactation; b) during this same period, the concentration of the MP decreases in milk; c) the MP itself becomes less active
to elicit oral grasping in pre-weaning pups than in newborns. These results indicate that the MP is active during the period
when pups are exclusively dependent on milk. The convergent changes in emission and reception of this pheromone may sequentially
warrant that pups are first attracted to the mammae, and then that they progressively disinvest the mother as they begin to
eat solid food and to be attracted by other conspecifics. 相似文献
40.
Summary. Across North America, populations of the pine engraver, Ips pini, differ in their expressed ratios of the two enantiomers of ipsdienol, the main component of its aggregation pheromone. We
confirm previous studies, showing that the percentage of (+)-ipsdienol ranged from approximately 40 to 70% for New York (NY)
males and less then 5% for California (CA) males. We performed line crosses including the F1, F2, and backcross generations
between these populations. These line crosses showed that most F1 hybrids produced an intermediate enantiomeric blend of ipsdienol
that was closer to the CA blend, with a frequency distribution peak near 15% (+)-ipsdienol. There was also strong segregation
to either parental type in the F2 and backcross generations, but not in a pattern that could be clearly described by a single
autosomal locus. There was also an X-linked effect that caused some individuals in the F1 to have phenotypes more characteristic
of NY populations. Generation means analysis confirms this X-linked effect, and also suggests a complicated autosomal dominance
by dominance epistatic interaction. Despite the appearance of segregation, these results suggest a more complicated system
of pheromone blend control than the single major gene previously found between divergent lines for high and low (+)-ipsdienol
blends from the hybrid zone in British Columbia.
相似文献