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51.
Summary. Females of both species start their pheromone-releasing activity on the second day after emergence at the beginning of the
photophase. During the present work, a peak of calling activity with close to 100% of active Ph. nigrescentella females was registered 1.5 hour after the light had been put on. The high pheromone release behaviour with 50% active females
lasted for 3 hours. The calling activity of the group of females was about 6 h/day. The beginning of a photophase under laboratory
conditions or an early morning in nature is a common period for sex pheromone release in the genus Phyllonorycter. (8Z,10E)-tetradecadien-1-yl acetate (8Z,10E-14:Ac), (8Z,10E)-tetradecadien-1-ol (8Z,10E-14:OH) and (8E,10Z)-tetradecadien-1-yl acetate (8E,10Z-14:Ac) in the ratio 96:4:traces as well as 8Z,10E-14:Ac and 8Z,10E-14:OH in the ratio 88:12 collected by Solid Phase Micro Extraction (SPME) were found to be specific for the calling periods
of virgin Phyllonorycter insignitella and Ph. nigrescentella females respectively. Field trapping experiments demonstrated that all three compounds are important for the attraction of
Ph. insignitella males while only 8Z,10E-14:Ac is the essential sex pheromone component for Ph. nigrescentella. The pheromone activity of all three compounds is reported for the first time. Addition of either 8Z,10E-14:OH or 8E,10Z-14:Ac to 8Z,10E-14:Ac did not have a significant effect on the attraction of Ph. nigrescentella males, while the efficiency of the three component blend was 5 times lower as compared to that of 8Z,10E-14:Ac. Our data demonstrate that 8Z,10E-14:OH and 8E,10Z-14:Ac play a dual function, they are minor sex pheromone components of Ph. insignitella essential for attraction of conspecific males and show an allelochemical, antagonistic effect on Ph. nigrescentella males and, thus, ensuring specificity of the mate location signal in two related Phyllonorycter species. 相似文献
52.
Tanya Pankiw Robert E. Page Jr M. Kim Fondrk 《Behavioral ecology and sociobiology》1998,44(3):193-198
Foraging and the mechanisms that regulate the quantity of food collected are important evolutionary and ecological attributes
for all organisms. The decision to collect pollen by honey bee foragers depends on the number of larvae (brood), amount of
stored pollen in the colony, as well as forager genotype and available resources in the environment. Here we describe how
brood pheromone (whole hexane extracts of larvae) influenced honey bee pollen foraging and test the predictions of two foraging-regulation
hypotheses: the indirect or brood-food mechanism and the direct mechanism of pollen-foraging regulation. Hexane extracts of
larvae containing brood pheromone stimulated pollen foraging. Colonies were provided with extracts of 1000 larvae (brood pheromone),
1000 larvae (brood), or no brood or pheromone. Colonies with brood pheromone and brood had similar numbers of pollen foragers,
while those colonies without brood or pheromone had significantly fewer pollen foragers. The number of pollen foragers increased
more than 2.5-fold when colonies were provided with extracts of 2000 larvae as a supplement to the 1000 larvae they already
had. Within 1 h of presenting colonies with brood pheromone, pollen foragers responded to the stimulus. The results from this
study demonstrate some important aspects of pollen foraging in honey bee colonies: (1) pollen foragers appear to be directly
affected by brood pheromone, (2) pollen foraging can be stimulated with brood pheromone in colonies provided with pollen but
no larvae, and (3) pollen forager numbers increase with brood pheromone as a supplement to brood without increasing the number
of larvae in the colony. These results support the direct-stimulus hypothesis for pollen foraging and do not support the indirect-inhibitor,
brood-food hypothesis for pollen-foraging regulation.
Received: 5 March 1998 / Accepted after revision: 29 August 1998 相似文献
53.
Summary. In a wind tunnel bioassay the effect of three concentrations of natural extracts of (1) Scots pine wood, Pinus sylvestris, and (2) larval frass on the behavioural response of unmated females and males of the old house borer, Hylotrupes bajulus, was tested and compared to the behavioural effects of the male-produced sex pheromone (3R)-3-hydroxy-2-hexanone. The influence on the behaviour of both sexes was found to be equally significant for the two higher
concentrated hexane extracts of wood and larval frass. Therefore several synthetic monoterpenes present in the extracts and
ethanol were tested at the two higher concentrations (1:100, 1:1000 vol/vol). Among the higher concentrated monoterpenoid
hydrocarbons [(+)-α-pinene, (+)-β-pinene, (+)-limonene], only α-pinene increased the activity, orientation towards scent source and interest towards conspecifics. The tests with higher
concentrated ethanol and the oxygenated monoterpenes [(-)-verbenone, (-)-trans-pinocarveol, (+)-terpinen-4-ol, (+)-α-terpineol, (-)-myrtenol] revealed that verbenone is the most effective stimulant for the females, followed by trans-pinocarveol, terpinen-4-ol and α-terpineol. For males, terpinen-4-ol was the only mediator significantly inducing attraction and orientation towards the scent
source combined with an interest in conspecifics apparent by fighting or courtship behaviour. Males did not respond to verbenone
which is a main compound of larval frass. Myrtenol and ethanol were ineffective in both sexes. In fact behavioural observations
suggest that the beetles were repelled by the high dose of myrtenol. Using the ten-fold lower dose of the synthetic monoterpenes
(1:1000 vol/vol), all semiochemicals except myrtenol lost activity. Myrtenol, however, induced behavioural responses, like
increased activity and orientation towards scent source, only at the low concentration. Based on the results, primary attraction
of unmated old house borer is probably mediated by monoterpenes of coniferous wood, while secondary attraction to infested
wood would occur in response to volatiles of larval frass.
Received 5 May 1999; accepted 30 September 1999 相似文献
54.
Pheromones produce dramatic behavioral and physiological responses in a wide variety of species. Releaser pheromones elicit
rapid responses within seconds or minutes, while primer pheromones produce long-term changes which may take days to manifest.
Honeybee queen mandibular pheromone (QMP) elicits multiple distinct behavioral and physiological responses in worker bees,
as both a releaser and primer, and thus produces responses on vastly different time scales. In this study, we demonstrate
that releaser and primer responses to QMP can be uncoupled. First, treatment with the juvenile hormone analog methoprene leaves
a releaser response (attraction to QMP) intact, but modulates QMP’s primer effects on sucrose responsiveness. Secondly, two
components of QMP (9-ODA and 9-HDA) do not elicit a releaser response (attraction) but are as effective as QMP at modulating
a primer response, downregulation of foraging-related brain gene expression. These results suggest that different responses
to a single pheromone may be produced via distinct pathways. 相似文献
55.
Abstract: Pheromone‐based monitoring is a promising new method for assessing the conservation status of many threatened insect species. We examined the versatility and usefulness of pheromone‐based monitoring by integrating a pheromone–kairomone trapping system and pitfall trapping system in the monitoring of two saproxylic beetles, the hermit beetle Osmoderma eremita (Coleoptera: Scarabaeidae) and its predator Elater ferrugineus (Coleoptera: Elateridae), which live inside hollow trees. We performed mark–recapture studies of both species with unbaited pitfall traps in oak hollows combined with pheromone‐baited funnel traps suspended from oak branches to intercept dispersing individuals. For O. eremita, the integrated trapping system showed that the population in the study sites may be considerably higher than estimates based on extrapolation from pitfall trapping alone (approximately 3400 vs. 1100 or 1800 individuals, respectively). Recaptures between odor‐baited funnel traps showed that males and females had similar dispersal rates, but estimating the number of dispersing individuals was problematic due to declining recapture probability between subsequent capture events. Our conservative estimate, assuming a linear decrease in capture probability, suggested that around 1900 individuals, or at least half of the O. eremita population, may perform flights from their natal host trees, representing higher dispersal rates than previous estimates. E. ferrugineus was rarely caught in pitfall traps. One hundred thirty‐nine individuals, likely almost exclusively females, were caught in odor‐baited funnel traps with approximately 4% recapture probability. If recapture probability over consecutive capture events follows that of O. eremita, this would correspond to a total population size of 2500–3000 individuals of the predator; similar to its supposed prey O. eremita. Our results demonstrate that pheromone‐based monitoring is a valuable tool in the study of species or life‐history stages that would otherwise be inaccessible. 相似文献
56.
近几年玉龙雪山生态旅游热升温,对该区域生态环境和植被资源的影响日趋显著,研究该区域高山草甸所受干扰对制定该区域的生态保护、可持续发展对策具有重要意义。为明晰人类活动对玉龙雪山高山草甸的影响,选取该区域典型高山草甸分布区域作为研究区,分析其草甸退化格局,通过干扰强度模型量化研究区的干扰格局,并利用方差分解确定不同干扰对高山草甸退化的贡献率。结果表明:(1)放牧干扰主要集中在牲畜饮水点附近,旅游干扰更多作用于景区观景台和寺庙附近,干扰活动分布与路径体系相吻合,游径布设和游客行为扩散模式决定了旅游干扰的格局;(2)草甸退化程度随干扰程度的增加而升高,干扰强度最大的区域与草甸的重度退化区域重合;(3)总体上旅游较放牧对草甸退化的贡献作用更大,但存在空间差异。在玉龙雪山牦牛坪景区,旅游干扰已逐渐取代放牧干扰成为主要干扰因素,且路径体系与旅游干扰格局具有较高的吻合度,对草甸退化格局的影响在逐渐增加。综上,建议选取使用率高的非正式路径修建为正式路径,保护和恢复分布在使用率低的非正式路径旁的植被和土壤,以降低旅游干扰对高山草甸的影响。 相似文献
57.
Hassane Mahamat Ahmed Hassanali Hezekiel Odongo Baldwyn Torto El-Sayeed El-Bashir 《Chemoecology》1993,4(3-4):159-164
Summary The accelerating effect of mature males of the desert locust,Schistocerca gregaria, on the maturation of immature male and female conspecifics was confirmed. The onset of sexual activity was found to correlate with yellowing of the male insects. Using the colour as an indicator of maturation, the maturation-hastening effect of an hexane extract from mature males was also confirmed. Likewise, volatiles from mature males placed in the upper storey of a two-chamber bioassay system (no visual or tactile contact possible) and charcoal-trapped volatiles from the mature males also induced accelerated maturation in recipient males placed in the lower storey. GC and GC-MS analysis of volatiles collected from 4-week-old mature males showed the presence of anisole, benzaldehyde, veratrole, phenylacetonitrile and 4-vinylveratrole, roughly at the ratio 4.8:7.0:3.3:79.8:5.0. In addition, guaiacol, phenol, benzoylnitrile, benzyl alcohol and 2-benzoyloxyphenylacetonitrile were present in smaller amounts. These compounds were either absent or found only in trace amounts in the female volatiles. Earlier, we had shown that essentially the same blend collected from younger males (10–20 d old, not yet demonstrating signs of maturation) induced strong aggregation of both sexes of adult desert locusts, suggesting a parsimonious role for the pheromone system: as an adult aggregation signal and as a maturation accelerant in young adults. 相似文献
58.
Thomas Hartmann Claudine Theuring Till Beuerle Elizabeth A. Bernays 《Chemoecology》2004,14(3-4):207-216
Summary. The alkaloid profiles of the life history stages
of the highly polyphagous arctiid Estigmene acrea were
established. As larvae individuals had free choice between
a plain diet (alkaloid-free) and a diet that was supplemented
with Crotalaria-pumila powder with a known content and
composition of pyrrolizidine alkaloids (PAs). Idiosyncratic
retronecine esters (insect PAs) accounted for approximately
half of the PAs recovered from the larvae. These alkaloids
were synthesized by the larvae through esterification of dietary
supinidine yielding the estigmines, and esterification of
retronecine yielding the creatonotines. The retronecine is
derived from insect-mediated degradation of the sequestered
pumilines (macrocyclic PAs of the monocrotaline type).
With one exception, the PA profiles established for larvae
were found almost unaltered in all life-stages as well as
larval exuviae and pupal cocoons. The exception is the
males, which in comparison to pupae and adult females,
showed a significantly decreased quantity of the creatonotines
and pumilines. These data support the idea that
the creatonotines are direct precursors of the PA-derived male
courtship pheromone, hydroxydanaidal. Crosses of PA-free
males with PA-containing females and vice versa confirmed
an efficient trans-mission of PAs from males to females and
then from females to eggs. In single cases a male bestowed
almost his total PA load to the female, and a female her total load
to the eggs. The results are discussed with respect to pheromone
formation, PA transmission between life-stages, and the
defensive role of PAs against predators and parasitoids 相似文献
59.
Foraging behavior and the mechanisms that regulate foraging activity are important components of social organization. Here
we test the hypothesis that brood pheromone modulates the sucrose response threshold of bees. Recently the honeybee proboscis
extension response to sucrose has been identified as a ”window” into a bee’s perception of sugar. The sucrose response threshold
measured in the first week of adult life, prior to foraging age, predicts forage choice. Bees with low response thresholds
are more likely to be pollen foragers and bees with high response thresholds are more likely to forage for nectar. There is
an associated genetic component to sucrose response thresholds and forage choice such that bees selected to hoard high quantities
of pollen have low response thresholds and bees selected to hoard low quantities of pollen have higher response thresholds.
The number of larvae in colonies affects the number of bees foraging for pollen. Hexane-extractable compounds from the surface
of larvae (brood pheromone) significantly increase the number of pollen foragers. We tested the hypothesis that brood pheromone
decreases the sucrose response threshold of bees, to suggest a pheromone- modulated sensory-physiological mechanism for regulating
foraging division of labor. Brood pheromone significantly decreased response thresholds as measured in the proboscis extension
response assay, a response associated with pollen foraging. A synthetic blend of honeybee brood pheromone stimulated and released
pollen foraging in foraging bioassays. Synthetic brood pheromone had dose-dependent effects on the modulation of sucrose response
thresholds. We discuss how brood pheromone may act as a releaser of pollen foraging in older bees and a primer pheromone on
the development of response thresholds and foraging ontogeny of young bees.
Received: 24 May 2000 / Revised: 26 September 2000 / Accepted: 15 October 2000 相似文献
60.
Summary. We describe the use of pieces of silicone tubing
to analyse the mandibular gland components of queen and
worker honeybees and show that these compounds can be
efficiently trapped on bis(trimethylsilyl)trifluoroacetamide
(BSTFA) treated pieces of tubing. The use of this technique
rather than that of solid phase microextraction (SPME) techniques
with commercially available fibres that have been
shown to be efficient at sampling secretions from the cuticle
of insects, is necessitated by a requirement for collection of
large sample numbers in a short space of time or for
sampling in the field. The technique may be generalised for
use with semiochemicals of low volatility in other insect
communciation systems. 相似文献