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1.
Alarm pheromones, which have been documented in many species of ants, are thought to elicit responses related to aggressive or defensive behaviour. The volatile odour 6-methyl-5-hepten-2-one is described as an alarm pheromone in several species of ants, including the Australian meat ant, Iridomyrmex purpureus. The alarm pheromone is released by displaying workers that aggregate in the characteristic collective display grounds, located mid-way between colonies or near contested food trees. Workers are typically more aggressive at the latter location, and the alarm pheromone may regulate the collective level of aggression. We investigated this possibility by exposing displaying workers to synthesised alarm pheromone 6-methyl-5-hepten-2-one in a field experiment, and measuring their aggressive behaviour. We found no evidence that exposure to synthesised alarm pheromone caused changes in the aggressive level of workers. Subsequent field experiments revealed that the pheromone functions as an attractant, thereby increasing the density of displaying workers. More densely populated workers also display more aggressively, indicating that the interaction rate of displaying workers may determine the level of aggression in collective displays. This underlying mechanism can explain why displaying ants are more aggressive at the more densely populated food-tree locations than those displaying at locations midway between two neighbouring colony nest sites. 相似文献
2.
The volatile components from the labial glands of males of six Japanese bumblebee species were analyzed and compared. Clear species‐specificity was found. Ethyl dodecanoate was identified as the major component from the glands of Bombus ( Bombus) hypocrita hypocrita and Bombus ( Bombus) hypocrita sapporoensis while dihydrofarnesal and dihydrofarnesol were the major components from Bombus ( Bombus) ignitus. Citronellol and trans, trans‐farnesol were found from Bombus ( Pyrobombus) ardens ardens and Bombus ( Diversobombus) diversus diversus, respectively. trans, trans‐Farnesol was also found from Bombus ( Diversobombus) diversus tersatus in Hokkaido. Such differences strongly suggest that these chemicals play an important role in reproductive isolation between sympatric species of Japanese bumblebees. 相似文献
3.
Alarm pheromones are important semiochemicals used by many animal species to alert conspecifics or other related species of impending danger. In this review, we describe recent developments in our understanding of the neural mechanisms underlying the ability of fruit flies, zebrafish and mice to mediate the detection of alarm pheromones. Specifically, alarm pheromones are detected in these species through specialized olfactory subsystems that are unique to the chemosensitive receptors, second messenger-signaling and physiology. Thus, the alarm pheromones appears to be detected by signaling mechanisms that are distinct from those seen in the canonical olfactory system. 相似文献
4.
Vespula germanica is a social wasp that efficiently exploits food resources. Odor cues, derived from substances located in wasp heads, have been proved to be central in conspecific attraction in this species. However, it remains unknown whether this attraction is related to foraging or defense responses. In this study we analyze conspecific attraction under two different contexts: at the nest entrance (defense) and under foraging conditions. We also test wasp response with two dosages of head extract and crosschecked the attractiveness of extracts obtained from different populations. We found no evidence of alarm response to head extracts either at the nest entrance or under foraging conditions. Moreover, no differences in attractiveness were found to both doses tested. Head extracts attract similarly in the same or a different population suggesting that conspecific attraction is not restricted to colony nestmates. 相似文献
5.
The objectives of this study were: (1) to test the existence of an aggregation pheromone in the gregarious psocid Cerastipsocus sivorii; (2) to compare the attractiveness of odors from different aggregations; (3) to test whether nymphs are able to chemically
recognize damage-released alarm signals. In a choice experiment conducted in the laboratory, we showed that psocids are able
to detect chemical cues from groups of conspecifics. Laboratory experiments also showed that nymphs are capable of chemically
recognizing the aggregations where they came from. Finally, in a field experiment, most aggregations dispersed when exposed
to the body fluids of a crushed conspecific, but no aggregations dispersed upon exposure to a crushed termite. The implications
of these results for the evolution of sociality in psocopterans are discussed. 相似文献
6.
Previously, we observed several instances in which Apis cerana japonica performed dancing around the hive entrance and smeared plant materials there immediately after scouting of Vespa mandarinia japonica. In this study, we conducted a series of attack simulation experiments with three hornet species to investigate whether the hive entrance dance is a specific response to V. m. japonica scouting. We also tracked dancing bees and dance‐follower bees to observe whether they perform hive entrance smearing. Only V. m. japonica scouting induced dancing, and we confirmed that dancing and dance‐follower bees performed smearing behavior at the hive entrance. These results suggest that the hive entrance dance informs nestmates of a specific emergency and of the urgent need to collect odorous plant materials as a counter‐attack strategy. 相似文献
7.
1. The kinetics of the efflux of P i and malate as well as the relationship between P i transport and intra- and extramitochondrial pH changes were studied in rat-liver mitochondria in the presence of rotenone and oligomycin at different pH's. 2. At high pH a fast efflux of Pi from the mitochondria occurs in the first few seconds, followed by a slow re-entry of Pi into the mitochondria. Under the same conditions the exit of malate shows a time lag of 2–4 sec. The exit of malate coincides with the re-entry of Pi. 3. In the presence of butylmalonate the exit of endogenous Pi is coupled with a concomitant alkalinization of the mitochondrial matrix space, as calculated from the distribution of 5,5-[14C]dimethyloxazolidine-2,4-dione. 4. The stoicheiometry of the Pi-hydroxyl exchange was found to be 1:1. 5. The kinetics of Pi transport are consistent with previous observations that there is a direct exchange between OH− and Pi, but not between OH− and malate. The equilibrium distribution of H2PO4− and OH− deviates from the Donnan distribution. This may be explained by assuming a pH-dependent binding of Pi in the mitochondria. 相似文献
8.
The social and reproductive behaviors of most mammals are modulated by pheromones, which are perceived by the vomeronasal organ (VNO). Vomeronasal transduction in vertebrates is activated through G-protein-coupled receptors, which in turn leads to the generation of inositol 1,4,5-trisphosphate (IP(3)) and diacylglycerol (DAG) by the activity of phospholipase C. DAG has been shown to gate the transient receptor potential channel 2, whereas IP(3) may play a role in stimulating the release of calcium from the endoplasmic reticulum store. To investigate the role of the alpha subunits of G(q/11) in the transduction process, microvillar membranes from female mice VNO were preincubated with a selective C-terminal peptide antibody against Galpha(q/11) and then stimulated with adult male urine. Incubation of VNO membranes with antibodies against Galpha(q/11) blocked the production of IP(3) in a dose-dependent manner. We were also able to impair the production of IP(3) when we stimulated with 2-heptanone or 2,5-dimethylpyrazine in the presence of antibodies against the alpha subunit of G(q/11). 2-Heptanone is a known pheromone that has been linked to VIR receptors. Thus, our observations indicate that the alpha subunits of G(q/11) play a role in pheromonal signaling in the VNO. 相似文献
9.
The fig tree, Ficus curtipes, hosts an obligate pollinating wasp, an undescribed Eupristina sp., but can also be pollinated by two inquiline (living in the burrow, nest, gall, or other habitation of another animal) wasps, Diaziella yangi and an undescribed Lipothymus sp. The two inquilines are unable to independently induce galls and depend on the galls induced by the obligate pollinator for reproduction and, therefore, normally enter receptive F. curtipes figs colonised by the obligate pollinators. However, sometimes the inquilines also enter figs that are not colonised by the pollinators, despite consequent reproductive failure. It is still unknown which signal(s) the inquilines use in entering the colonised and non-colonised figs. We conducted behavioural experiments to investigate several possible signals utilised by the inquilines in entering their host receptive figs. Our investigation showed that both inquiline species enter the receptive F. curtipes figs in response to the body odours of the obligate wasps and one of the main compounds emitted by the figs, 6-methyl-5-hepten-2-one. The compound was not found in the pollinator body odours, suggesting that the two inquiline wasps can utilise two signals to enter their host figs, which is significant for the evolution of the fig-fig wasp system. These inquilines could evolve to become mutualists of the figs if they evolve the ability to independently gall fig flowers; there is, however, another possibility that a monoecious Ficus species hosting such inquilines may evolve into a dioecious one if these inquilines cannot evolve the above-mentioned ability. Additionally, this finding provides evidence for the evolution of chemical communication between plants and insects. 相似文献
10.
We conducted a laboratory study to determine if male fathead minnows, Pimephales promelas, altered their territorial behaviour associated with reproduction in response to combinations of visual and chemical cues from northern pike, Esox lucius. We introduced the following stimuli to a territorial male: a brick (control), fathead minnow alarm pheromone, a pike fed brook stickleback, Culea inconstans, or a pike fed fathead minnow. The territorial behaviour of males did not change when the control was added. Male minnows experiencing threat from pike fed stickleback significantly reduced the frequency at which they performed three territorial behaviours, but, within 12 h, had returned to pre-exposure activity levels. Male minnows subjected to alarm pheromone alone and to pike fed fathead minnow significantly reduced their territorial behaviour, abandoned their nests, and did not return to pre-exposure levels of activity after 24 h. We suggest that because risk of predation triggers prolonged decreases in territorial defense, it may affect competition between nesting males and female mate choice. We conclude that fathead minnows can assess the severity of predatory threat and adjust their reproductive behaviour accordingly. 相似文献
11.
Oligomers of 5-amino-8-vinyl-phthalazine-1,4(2 H,3 H)-dione exhibit about 0.05% of the chemiluminescence quantum yield of the corresponding ‘monomer unit’, i.e. 5-amino-8-ethyl-phthalazine-1,4(2 H,3 H)-dione which has a similar quantum yield to luminol. The quantum yields of copolymers of 5-amino-8-vinyl-phthalazine-1,4(2 H,3 H)-dione (1a) with methyl methacrylate or with styrene increase up to 1000-fold, relative to the quantum yield of oligomers of (1a). Thus the monomer units of methyl methacrylate or styrene appear to act as ‘spacers’ between the lumigenic groups. α,ω-Bis[(5-amino-phthalazine-1,4(2 H,3 H)-dion-)8-yl] alkanes show an analogue ‘distance’ effect: the chemiluminescence quantum yield increases with increasing alkane chain length. As the fluorescence of the corresponding amino phthalates (which are intermediates in the synthesis of the phthalazine diones) is only slightly influenced by the distance between the lumigenic groups it is suggested that a mainly chemical ‘distance effect’ is working here: the smaller the intramolecular distance between the hydrazide groups the more inhibition exists in respect of the oxidative reaction producing the luminol-type chemiluminescence. 相似文献
12.
In order to better understand the effects of LHRH administration on testicular function in adult rat, we compared the inhibitory effects of LH and the LHRH analogue [D-Ser-(TBU) 6, des-Gly-NH 2 10]LHRH ethylamide upon testicular steroidogenesis and LH, FSH and prolactin receptor contents. Administration of LH as well as LHRH analogue resulted in a marked decrease of LH receptor levels, accompanied by a blockage at the level of 17-hydroxylase activity. We have been able to demonstrate that multiple LH administration can achieve a testicular desensitization comparable to that observed after LHRH agonist treatment. 相似文献
13.
This study tested the hypothesis that the Src/Raf/MAPK signaling pathway is involved in the facilitation of the lordosis and proceptive behaviors induced by progesterone (P) and its ring A-reduced metabolites in ovariectomized, estradiol-primed rats. Intraventricular (icv) infusion of PP2 (7.5, 15 and 30 µg), a Src kinase inhibitor, significantly depressed P-dependent estrous behavior (lordosis and proceptivity) in estradiol-primed rats. Icv infusion of 30 µg of PP2 also significantly attenuated estrous behavior induced by the ring A-reduced P metabolites 5α-dihydroprogesterone (5α-DHP) and 5α-pregnan-3α-ol-20-one (allopregnanolone). PP2 did not inhibit estrous behavior induced by administration of high doses of estradiol alone to ovariectomized rats. We also assessed if the ventromedial hypothalamus (VMH) is one of the neural sites at which progestins activate Src signaling to facilitate estrous behavior. Bilateral administration of 15 µg of PP2 into the VMH inhibited the stimulation of both lordosis and proceptive behaviors elicited by subcutaneous P administration to estradiol-primed rats. These results suggest that progestins act through Src/Raf/MAPK signaling to initiate estrous behaviors in estrogen-primed rats. This event is one component of the cellular pathways leading to the display of estrous behaviors induced by P and its ring A-reduced metabolites in female rats. 相似文献
15.
Abstract. The secretion from the mandibular glands of males of the leaf-cutting ant Atta sexdens rubropilosa is responsible for the reaction of workers outside the nest at the time of sexual swarming. Workers respond with excitability and aggression when presented with the natural mixture of 4-methyl-3-heptanol and 4-methyl-3-heptanone, which is contained in the secretion of the male mandibular glands. Workers respond quickly to fractional amounts of one male equivalent. 4-Methyl-3-heptanone, from the virgin female mandibular glands causes much less response in workers, whereas an equimolar mixture of male and female pheromones gives a still less clear response. The male pheromone plays the most important part in the communication of workers outside the nest at this time. 相似文献
17.
Many prey species suffer from different predators in the course of their ontogeny. Hence, the alarm signal a small prey individual sends can have a different meaning than the signal a large prey individual sends, both for small and for large receivers. Larvae of Western Flower Thrips face predators that attack only small larvae, or predators that attack small larvae and large larvae. Furthermore, thrips larvae release a two‐component alarm pheromone, which varies in composition with larval age. Here, we study whether their response to alarm pheromone varies with composition of the pheromone. First, we confirmed that large and small larvae respond when nearby larvae of both sizes were prodded with a brush to induce alarm pheromone excretion. Subsequently, we tested whether thrips larvae of a given size respond differentially to alarm pheromone excreted by a small or large companion larva. We analyzed two types of behavior used in direct defense against a predator and one type of escape response. Only small (not large) larvae attempted to escape more frequently in response to excretions from a large larva. This difference in response could have been due to the alarm pheromone or to the companion larva in the vicinity. We subsequently tested for, but did not find, an effect of size of the companion larva on the behavior of the test larva when exposed to synthetic pheromone mimicking that of a large larva. Finally, we tested how pheromone composition affects antipredator behavior by exposing thrips larvae to synthetic pheromones differing in amount and ratio of the two components. Only for small larvae, we found significant changes in escape behavior with pheromone amount, and a trend with the ratio. Overall, we conclude that small thrips larvae respond differentially to alarm pheromones excreted by small and large larvae and that this differential response is due to differences in pheromone quantity and possibly also quality. Our results suggest that responses to alarm signals can vary with the chemical composition of those alarm signals. 相似文献
18.
Females of the parasitoid wasp Glyptapanteles flavicoxis (Marsh) (Hymenoptera: Braconidae) deposit sex pheromone on substrate that elicits attraction and wing fanning in conspecific males. We tested the hypothesis that wing fanning sound induces a behavioral response from females which, in turn, affects the males’ orientation toward them. Females exposed to playback of the males’ wing fanning sound engaged in short flights, with sound characteristics different from those of the males’ wing fanning sound. In two‐choice bioassays, playback of the females’ flight sound attracted significantly more males than a silent control stimulus, and in combination with pheromone‐containing body extract of females it attracted more males than female body extract alone. Our data support the conclusion that the males’ wing fanning induces sound and visual reply signals from females that help males orient toward them. 相似文献
19.
When medium workers of the leaf-cutting ant Atta sexdens sexdens are presented with the compounds 3-ethyl-2,5-dimethylpyrazine and methyl 4-methylpyrrole-2-carboxylate in various proportions in a trail-following bioassay, they show the highest performance for the 14:1 mixture over other mixtures or the pure compounds. This preferential mixture corresponds with the proportion of both compounds described for the venom gland, which is the source of the natural trail pheromone in these leafcutting ants. 相似文献
20.
A method and its validation is described for the radioimmunological measurement of deoxycorticosterone (DOC) in bovine serum. Levels of DOC and progesterone were determined in six pregnant heifers from one to three weeks before and during parturition. Levels of these steroids fluctuated widely from day to day and tended to be inversely related (r = -0.24). High levels of DOC in conjunction with low levels of progesterone at or near parturition are suggestive that DOC is involved in the parturition process. 相似文献
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