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1.
Observations of the attraction of males of the pea moth, Cydia nigricana (F.), to vegetation which had been in the immediate vicinity of sex-attractant traps are described. The moths exhibited sexual activity on arrival and the vegetation remained attractive for at least 60 min after removal of the traps. By increasing the dose of attractant in a trap, it was possible to contaminate adjacent vegetation with enough attractant to be detectable by electroantennographic and gas chromatographic techniques.
Zusammenfassung Es werden Beobachtungen beschrieben über die Anlockung von Weibchen des Erbsenwicklers, Cydia nigricana durch Vegetation, die in unmittelbarer Nähe von Pheromonfallen gewesen war. Die Falter weren bei der Ankunft sexuell aktiv und die Vegetation blieb für mindestens 60 Minuten nach Entfernung der Fallen attraktiv. Durch Steigerung der Pheromonmenge in einer Falle wurde es möglich, die benachbarte Vegetation so zu kontaminieren, dass Pheromon mit elektroantennographischen und gaschromatographischen Methoden nachweisbar wurde.
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2.
Interactions between pheromone traps were investigated in a series of trap spacing experiments involving the pea moth, Cydia nigricana. Central traps in circles or lines of traps, always caught fewer moths than isolated traps. This effect was significant even when the radius of the circle or the spacing in the line was 100 m, indicating a range of attraction of at least this distance. In lines of three traps across the wind, the central trap caught fewer moths than the outer traps. In similar lines along the wind, the upwind trap caught more moths than either the central or downwind traps, whose catches were equal. An explanation for these results is proposed, based on overlapping trapping zones, and supported by independent field observations. The implications of these results for pheromone trapping in general are discussed.
Zusammenfassung Wechselwirkungen zwischen Pheromonfallen für den Erbsenwickler, Cydia nigricana (F.), wurden in einer Versuchsreihe mit verschiedenen Fallenabständen untersucht. Fallen, die je 100 g (E,E)-8-10-Dodecadienylacetat auf Gummistopfen enthielten, wurden jeweils an einem Ort in mehreren räumlichen Anordnungen plaziert.An der zentralen Falle innerhalb eines Kreises oder einer Linie wurden immer weniger Falter gefangen als an isolierten Fallen. Dieses Resultat war sogar dann signifikant, wenn der Kreisradius oder der Fallenabstand in der Linie 100 m betrug. Demnach beträgt die Anlockungsdistanz mindestens diesen Wert. Wenn drei Fallen quer zur Windrichtung angeordnet waren, fing die zentrale Falle weniger als die peripheren Fallen. Wenn drei Fallen in der Windrichtung angeordnet waren, fing die windaufwärts plazierte Falle mehr als die zentrale und die windabwärts plazierte Falle; bei den zwei letzteren war der Fang gleich gross.Eine Erklärung dieser Ergebnisse wird vorgeschlagen und zwar aufgrund sich überdeckender Fangzonen und von Direktbeobachtungen im Feld. Folgerungen daraus werden diskutiert inbezug auf den Fang mit Pheromonfallen im Allgemeinen.
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3.
Synopsis This paper analyses the distribution of longline catches of swordfish, Xiphias gladius, and six species of pelagic elasmobranchs, during a fishing voyage in the tropical eastern Atlantic. Seven scales of sampling units, ranging from about 0.72 to 7.2 km were used. Observed frequencies of appearance of each species in the basic sampling unit, were compared with theoretical frequencies obtained from the Poisson and negative binomial distributions. For the study of the interspecific relationships, contingency tables were used and the degree of association was estimated using the 2test and the coefficient v of Kendall. The catch distribution of the swordfish and the devil ray (Mobula sp.) can be explained by both randomness and a slight trend to association. For the pelagic sharks, a clear trend towards intraspecific clustering was found. Catches of two species of the genus Carcharhinus showed the most positive trends to interspecific association, especially in short ranges, probably due to attraction to previously hooked fish. The possible causes of these distributions are discussed.  相似文献   

4.
5.
Brief exposures of male Choristoneura rosaceana and Argyrotaenia velutinana to the plumes generated by lures releasing 3-component pheromone blends specifically tuned for each species or by commercially distributed Isomate OBLR/PLR Plus pheromone rope dispensers induced markedly different subsequent behavioral responses to pheromone. A greater proportion of C. rosaceana males took flight and successfully oriented toward lures 24 h after preexposure to a lure, a rope, or the lure–rope combination in a sustained-flight wind tunnel compared to naïve moths. Flights were also longer for preexposed than naïve moths. Preexposed male C. rosaceana were not more likely to fly toward ropes 24 h after preexposure. By contrast, fewer male A. velutinana oriented to lures 24 h after preexposure than did naïve moths. Those preexposed A. velutinana successfully locking onto plumes from lures flew for significantly shorter intervals than did unexposed moths. Electroantennograms revealed no changes at the periphery 15 min and 24 h after preexposure. For A. velutinana, the long-lasting effect was decreased attraction to a lure and increased attraction to a rope. For C. rosaceana, pheromone preexposure increased responsiveness to its authentic blend. This behavioral evidence is sufficient to explain why sexual communication of C. rosaceana is more difficult to disrupt than that of A. velutinana. Furthermore, it suggests a more complete blend of pheromone may be necessary to disrupt the former species but not the latter when using rope dispensers.  相似文献   

6.
Streptanthus tortuosus Kell. suspension cells will grow in a medium with sucrose as carbohydrate source. It was investigated whether the cells are able to take up sucrose or whether sucrose has to be hydrolyzed to glucose and fructose which eventually are taken up. The detailed quantitative analysis of sugar-uptake rates in the low concentration range up to 1 mM showed the following features: (i) There is definitely no sucrose-uptake system working in the low concentration range; any uptake of radioactivity from labelled sucrose proceeds via hydrolysis of sucrose by cell-wallbound invertase. (ii) Hexoses are taken up by two systems, a glucose-specific system with a K m of 45 M and a high V max for glucose and a K m of 6 mM and a low V max for fructose, and a fructosespecific system with a K m of 500 M and high a V max for fructose and a K m of 650 M and a low V max for glucose. (iii) There is a more than tenfold preference for uptake of the fructose derived from sucrose versus uptake of free fructose, with the result that the kinetic disadvantage of the fructoseuptake system compared to the glucose-uptake system is diminished if sucrose is supplied as the carbon source. It is speculated that invertase might work as an enzyme aiding in fructose transport.Abbreviations FCCP carbonylcyanide-p-trifluoromethoxyphenylhydrazone - FW fresh weight  相似文献   

7.
The close-range orientation behaviour of male pea moths, Cydia nigricana (F.) (Lepidoptera: Tortricidae), to a substrate contaminated with synthetic sex pheromone was studied in the field. The substrate was a sheet of polypropylene grass on a 1 m diam arena, on the upwind edge of which a pheromone trap had been placed previously for 1 h. After removal of the trap, moths continued to be attracted to the arena and to the vacated trap position. Video-recorded tracks showed that the moths behaved anemotactically whilst on the arena. When the arena was revolved so that the vacated trap position was on the downwind edge, moths continued to fly upwind on the arena, even though they were flying away from the original trap position and down a concentration gradient.  相似文献   

8.
Leonard Nunney 《Oecologia》1996,108(3):552-561
The guild of cosmopolitan Drosophila coexist almost worldwide and yet the mechanisms that underlie this coexistence are unknown. The larval resource of the guild is decaying fruit and vegetables, but the species show little specialization and can coexist on a single resource, such as oranges. In southern California the guild includes D. simulans (SIM), D. melanogaster (MEL), D. pseudoobscura (OBS), D. immigrans (IMM), D. hydei (HYD) and D. busckii (BUS). These species show consistent differences in their colonization of decaying organges, differences that may promote their coexistence. This study tested whether the colonization pattern of a species is determined primarily by attraction to specific resource types (decayed or fresh organges), by ability to colonize new resource patches, or by dependence on a successional sequence of Drosophila species. The experiments compared oranges that were pre-aged prior to a colonization period and showed that the colonization pattern of each species (except OBS) was driven primarily by its decay-dependent attraction to oranges. While OBS exhibited a pattern of colonization independent of pre-aging, the remaining species all showed some preference for older (7-day pre-aged) over fresh oranges. Their overall pattern of attraction, ordered by high relative abundance on fresher organges, was SIM>MEL=IMM>HYD=BUS. BUS, a specialist on decaying plant material, was the only species that showed a preference for 11-day over 7-day oranges. Pre-aging the oranges under covers, to prevent prior colonization by Drosophila, did not change the interspecific pattern of colonization, indicating that microbial decay was driving the changes in attraction. The patterns of attraction separated two ecologically similar pairs (SIM from MEL; IMM from HYD) and published data on ethanol tolerance show that, in each pair, the earliest colonizer has the lower tolerance. This suggests an important interplay between colonization patterns and physiological optima.  相似文献   

9.
Stimulation of G-protein activity by the amphipathic tetradecapeptide mastoparan is well documented in animal systems and occurs via mimickry of the third cytoplasmic domain of the cognate seven-transmembrane-span (7TMS) receptor. Binding of guanosine 5-O-thiotriphosphate to microsomal and plasma-membrane fractions from Pisum sativum L. and Zea mays L. was stimulated by the tetradecapeptide mastoparan analogue mas 7 over a narrow concentration range, with maximal effect exerted at 10 M peptide, while the nonamphipathic analogue, mas CP, which differed from mas 7 by only one amino acid, was ineffective at promoting binding. This stimulation could be completely abolished by inclusion of low concentrations of the non-ionic detergents nonanoyl-N-methylglucamide and Lubrol PX. Taken together, these data provide good evidence for the existence of G-protein-linked 7TMS receptors in higher plant systems.Abbreviations GTPS guanosine 5-O-thiotriphosphate - MEGA-9 nonanoyl-N-methylglucamide - 7TMS 7 trans-membrane span The authors wish to acknowledge the financial support of the European Community (I.R.W.), ICI and the Science and Engineering Research Council (A.W.) and the Agricultural and Food Research Council (P.A.M.).  相似文献   

10.
The focal-animal technique assumes the continuous recording of the behavior of an individual during a certain time interval. The length of this interval (sampling unit) can be problematic when estimating the duration of behavioral acts. Two acts from the behavioral repertoire of the ant Leptothorax fuenteiwere focused on in this work at different ranges of temporal scales. Analyzing these acts we show the possibility of existence of a sampling artifact, in such a way that the estimates of the durations of the acts would be forced to depend upon the length of the sampling unit that is being used.  相似文献   

11.
Five principle monoterpenoid and other constituent volatile chemicals of sunflower heads were combined to resemble two lines of sunflower (Helianthus annuus L.): one U.S.D.A. standard line and one French line which was poorly visited by insects (Etievant et al., 1984). Field trials of attraction to red sunflower seed weevils (Smicronyx fulvus Le Conte, Coleoptera: Curculionidae) showed that one was clearly preferred over the other. The more attractive mixture contained -pinene, -pinene, limonene, camphene and bornyl acetate in a ratio resembling that of Flath et al. (1985) rather than that described by Etievant et al. (1984). One or two volatiles were deleted from the optimal blend but only mixtures of five volatiles showed the highest attraction. Substitution of sabinene, another volatile prominent in sunflower, for one of the five in the optimal blend also decreased attraction of seed weevils. When the monoterpenoid components and green leaf volatiles in the traps resembled the ratios of most of the prominent volatiles of sunflower, attraction was significantly greater than controls.  相似文献   

12.
Summary The Threonine-Glycine (Thr-Gly) region of the period gene (per) in Drosophila was compared in the eight species of the D. melanogaster subgroup. This region can be divided into a diverged variable-length segment which is flanked by more conserved sequences. The number of amino acids encoded in the variable-length region ranges from 40 in D. teissieri to 69 in D. mauritiana. This is similar to the range found within natural populations of D. melanogaster. It was possible to derive a Thr-Gly allele of one species from that of another by invoking hypothetical Thr-Gly intermediates. A phylogeny based on the more conserved flanking sequences was produced. The results highlighted some of the problems which are encountered when highly polymorphic genes are used to infer phylogenies of closely related species.  相似文献   

13.
Uptake and xylem loading of organic sulfur and nitrogen were analyzed in detached mycorrhizal (Laccaria laccata L.) roots of pedunculate oak (Quercus robur L.) seedlings using radiolabeled reduced glutathione (GSH) and glutamine (Gln) for transport analyses. The experiments showed for the first time that GSH is taken up by plant roots from the nutrient solution and is partially allocated to the shoot. Apparently, GSH produced during mineralization processes in the soil can be used by plant roots as a sulfur source. GSH uptake into the roots showed biphasic kinetics within the concentration range studied (0–500 M) with maximum transport velocities (v max) and substrate affinities (K m) that were similar to the kinetics of Gln uptake. GSH uptake kinetics were also in the same range as previously reported for sulfate uptake by mycorrhizal roots of pedunculate oak. It may therefore be assumed that GSH and sulfate uptake can be of comparable significance for sulfur nutrition, provided both sulfur sources are available at similar concentrations at the sites of uptake. Xylem loading of GSH and Gln showed monophasic transport kinetics with v max significantly lower than observed for the two respective uptake systems and, as indicated by the K m-values, a substrate affinity between the high and the low affinity uptake systems. The possible nature of the transport systems for GSH and Gln is discussed.  相似文献   

14.
Osmoderma eremita is a threatened scarab beetle living in the hollows of old deciduous trees and is regarded as an umbrella species of the beetle fauna associated with this habitat. Several methods like pitfall trapping and wood mould sampling have been used to monitor the occurrence of O. eremita, but these methods cannot be applied for trees with certain characteristics. Recently, (R)-(+)--decalactone was identified as a male-produced sex pheromone of the species. Here, we show that -decalactone can be detected in hollow trees by air sampling and that the presence of the compound is strongly correlated with the occurrence of living male beetles in the same trees. Air was sampled from tree cavities and extracts analysed using gas chromatography–and mass spectrometry. There was a 89% match between the detection of -decalactone in extracts and the occurrence of male O. eremita±2 days from the sampling event. In the absence of males, samples never contained -decalactone, and the presence of this compound in a tree cavity appears to be a good predictor of O. eremita occupancy. Air sampling can be a useful complement to other methods when trying to detect as many trees housing this beetle as possible, which is crucial when estimating populations sizes and developing conservation strategies for this species.  相似文献   

15.
During four cruises in continental shelf waters of the northern Gulf of Mexico in the winters of 1981–83, we performed quantitative studies on the grazing of the copepods Acartia tonsa, Centropages velificatus, and Eucalanus pileatus, on phytoplankton using natural particulate assemblages as food. Stations were in, or adjacent to the plume of the Mississippi River, thereby providing wide spectra of phytoplankton and suspended riverine particulate concentrations. Phytoplankton cell volume was converted to carbon, and this, coupled with carbon content measurements of these three copepod species, allowed comparisons of daily ingestion effort even though the copepods were of different sizes. Data were expressed in the same units (% of copepod body carbon ingested copepod –1 d–1) for each species. Over similar ranges of phytoplankton carbon concentrations (0.21–92.06 gCl–1), Acartia tonsa had higher carbon-specific ingestion rates (x = 22.31%, range = 0.08–152.37%) than C. velificatus (x = 2.8%, range = 0.00–31.09 %) or E. pileatus (x = 1.27%, range = 0.10–2.80%). Carbon-specific ingestion rates increased with increasing phytoplankton carbon concentration for A. tonsa (R2 = 0.81) and there was no evidence of saturated feeding on the carbon concentrations offered. A similar, but weaker trend was evident for E. pileatus (R2 = 0.71), but not C. velificatus (R2 = 0.49). Over a wide range of suspended particulate concentrations (10.6–95.2 mg l–1), there was no systematic effect of particulates on carbon-specific ingestion rate for any of the three copepod species. However, A. tonsa appeared more adept at grazing in highly turbid water than C. velificatus or E. pileatus.  相似文献   

16.
The efficiency of herbivore exclusion by ants on the vetch Vicia angustifolia L. (Leguminosae) with extrafloral nectary, mediated by ant attraction to aphids was investigated in a field census and laboratory experiments. In the field, workers of Lasius japonicus Santschi and Tetramorium tsushimae Emery frequently visited plants of the vetch parasitized by aphids of Aphis craccivora Koch, but only a few workers visited plants without aphids. An increase in the number of ants visiting a plant with increasing numbers of aphids caused a decrease in the number of larvae of the weevil, Hypera postica Gyllenhal. Therefore, the efficiency of herbivore exclusion by ants was higher on plants parasitized by Ap.craccivora aphids than that on plants unparasitized by aphids. In the laboratory experiments, L.japonicus workers frequently patrolled not only shoots with Ap.craccivora aphids but also shoots without them. However, T.tsushimae workers visited mainly shoots with Ap.craccivora aphids but less frequently on shoots without aphids. Therefore, L.japonicus workers excluded herbivores more efficiently on plants of the vetch than T.tsushimae workers. Consequently, the efficiency of herbivore exclusion by ants on the vetch can be influenced directly by differences in ant species and indirectly by the presence of aphids on plants. The present study highlights the significance of indirect interactions between ants and plants with extrafloral nectary, mediated by ant attraction to aphids for herbivore exclusion of plants.  相似文献   

17.
Measurements of root-length density (RLD) in a range of 31 apple, kiwifruit, peach, Asian pear and grape orchards were used to derive indices to describe the exploration and exploitation of rooting volumes. Orchards were of various ages and located on a range of soil types, geographic regions, management systems etc. Data were obtained from core samples of volume 1.66×10-4 m3 randomly taken within a standard volume, determined by average planting grids, of 2 m radius centred on tree stems, and 1 m depth. Root systems were described using an exploitation index, E(), and an exploration index, E(0). E() is defined as the proportion of the soil volume which contains roots at RLD greater than or equal to some specified value, . E(0) is defined as the proportion of the soil volume which contains roots at any RLD greater than zero. These indices are dependent on sample size, as are all volumetric or soil-coring data.Estimates of E(0) for each orchard were obtained as the proportions of cores containing any RLD>O and assessed for dependence on species. Peach trees had a significantly higher value of E(0), equal to almost 1.0, compared to the other four species where E(0) was approximately 0.8 (p0.01) or less. There was also some variation with age. E(0) was lower for very young plants which had not fully occupied the sampled soil volume. Exploration indices for woody roots increased with rootstock age but otherwise did not explain large differences in E() between species for given values.For example at =0.05×104 m.m-3, E() was approximately 0.45 for peach and kiwifruit, and 0.05 for apple, Asian pear and grape, whereas at =0.5×104 m.m-3 the corresponding values were 0.1 and almost zero. Negative exponential curves relating E(), scaled by dividing by E(0), to were fitted for each of the 31 orchards. Exponents for these curves, k, were significantly smaller for kiwifruit and peaches than apples, grapes and Asian pears (p0.05), and smaller for apples than grapes and Asian pears (p0.05). A larger k implies a rapid fall-off in E() as increases. Although all five species contained zero and low RLD samples, only kiwifruit and peaches contained higher RLD values and consequently have higher mean RLD. This trend was consistent across all soils, regions, sampling dates, and plant ages.The analyses demonstrate that core sampling can give useful insights into macro-scale root-system distribution, such as the proportion of a soil volume explored and how it is exploited. If positions of core samples are noted during sampling using angular direction, depth and radial distance as spatial coordinates the method can be used to describe root-system structures.  相似文献   

18.
Host orientation by two nitidulid beetles was compared: Stelidota geminata (Say), which is very broad in its' host range, and Stelidota octomaculata (Say), a species whose feeding is restricted primarily to acorns. In a no-choice assay, both species responded to all food substrates offered and neither showed a significant preference among substrates (except banana versus wood fungi for S. octomaculata), or between aseptic and inoculated treatments; however, S. geminata readily displayed both phototactic flights and host-orienting flights, whereas S. octomaculata never exhibited phototactic flight and never responded to food odors by flying to the source. Furthermore, when upwind-walking response was compared, S. octomaculata walked to the source at a rate of 0.16±0.01 cm/s, which was significantly lower than that of S. geminata, with a rate of 0.54±0.02 cm/s. Turning frequency on the way to the source also differed between the two species, whereas distance traveled, number of pauses, and duration of pauses did not differ significantly. We submit that both species represent olfactory generalists, and that the restricted host range of S. octomaculata compared to S. geminata is not mediated by differences in long-range response to host odors, but rather is due to differences in other behaviors such as a reduced rate of locomotion, post-landing behavior, and possibly ecological factors.  相似文献   

19.
The attraction range of a human bait for Aedes albopictus (Diptera, Culicidae) adults and its absolute density in the range were estimated by a new removal method which is applicable to populations with immigrants. In this model, the number of mosquitoes removed during the kth collection unit yk, is expressed as where x0 is the initial number of mosquitoes in the attraction range, a is an index directly proportional to collection efficiency, b is the number of immgirants per collection unit and s(=e−a) is the survival rate of mosquitoes in the attraction range per collection unit. From the result of successive two collections with various interval distances, it was considered that Aedes albopictus adults are attracted to a human bait from the distance of 4–5 m in the bamboo forest on the calm day. The applicability of this method for the population census of forest mosquitoes was discussed.  相似文献   

20.
The effect of geographical differences in breeding cycles on the recruitment variation of the limpets — Patella vulgata L., P. aspera Röding and (to a limited extent) P. depressa Pennant — has been studied over much of their range in Britain and NW. Europe. In spite of considerable annual and local variation in recruitment success, broader patterns can be distinguished, which can be linked to spawning times and factors affecting the survival of newly-settled spat. The breeding cycles of P. vulgata and P. aspera differ across their ranges in that, in both species, spawning begins, and gametogenesis ends, earlier in the north and east than in the south and west. The cause of these differences can be correlated with geographical and annual differences in sea temperature over the potential breeding periods, and can be related to the regional incidence of conditions found experimentally to be necessary for successful settlement and survival of spat during a critical stage of their growth. The significance of this temperature window in determining the littoral and geographical distribution of the species is discussed.  相似文献   

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