共查询到20条相似文献,搜索用时 15 毫秒
1.
Abstract. The behavioural response of adults of the pollen beetle, Meligethes aeneus F. (Coleoptera: Nitidulidae), to the odour of one of their host-plants, oilseed rape ( Brassica napus L.), was observed in the laboratory using a fourarmed airflow olfactometer, and under semi-natural conditions using a markrelease–recapture technique. Oilseed rape leaf and flower odour was attractive to pollen beetles in the olfactometer and they dispersed upwind from the centre of a circular array (radius 20 m) of yellow water traps, baited with extracts of oilseed rape leaves or flowers. The dispersal of pollen beetles in the absence of oilseed rape odour was predominantly downwind and crosswind. The percentage recapture of pollen beetles was significantly greater in traps baited with rape flower extracts than leaf extracts. Pollen beetles can use odour-mediated upwind anemotaxis to locate oilseed rape plants from distances of at least 20 m over open ground. 相似文献
2.
Response of the pollen beetle Meligethes aeneus to volatiles emitted by intact plants and conspecifics 总被引:1,自引:0,他引:1
The response of the pollen beetle Meligethes aeneus Fab. (Coleoptera, Nitidulidae) to the volatiles of undamaged plants and conspecifics was tested in a Y-tube-olfactometer-bioassay. Beetles that had hibernated preferred significantly the volatiles emitted by their most important host plant, oilseed-rape (Brassica napus L. ‘Lorar’) in the early bud-stage. However, the odour emitted by rye (Secale cereale L.), tomato plants (Solanum lycopersicum L.), and yarrow (Achillea millefolium L.) were also attractive when tested against the corresponding growing-medium. Dock plants (Rumex obtusifolius L.) and touch-me-not (Impatiens parviflora L.) possessed no attractive properties. When tested against each other, oilseed-rape was preferred significantly by M. aeneus above all other plants, with the exception of tomato. The results indicate that M. aeneus is able to locate its host plant by olfactory stimuli in the early bud-stage, i.e. in that stage in which the infestation begins in the field and when the typical yellow colour and floral scent of oilseed-rape are absent. Female pollen beetles avoided significantly the volatiles emitted by female conspecifics and an ether extract of conspecifics of mixed sex, while volatiles from males had no significant effect on females. Furthermore, males showed no preferences when responding to conspecific odour in the olfactometer. These results suggest the existence of an epideictic pheromone for M. aeneus. 相似文献
3.
The objective of this study was to evaluate pollen dispersal inBrassica napus (oilseed rape). The selectable marker, used to follow pollen movement, was a dominant transgene (bar) conferring resistance to the herbicide glufosinate-ammonium. Transgenic and non-transgenic plants of the cultivar Westar were planted in a 1.1 ha field trial, with the transgenic plants in a 9 m diameter circle at the centre, surrounded by non-transgenic plants to a distance of at least 47 m in all directions. A 1 m circle of non-transgenic plants was sown in the centre of the transgenic area to allow estimation of the level of pollen dispersal when plants were in close contact. Honeybee hives were placed at the trial site to optimize the opportunity for cross-pollination. During the flowering period, regular observations were made of the number of plants flowering and the number and type of insects present in 60 1 m2 areas. These areas were located uniformly around the plot at distances of 1, 3, 6, 12, 24, 36 and 47 m from the edge of the 9 m circle of transgenic plants. Seed samples were harvested from each of the 7 distances so that approximately 20% of the circumference of the plot was sampled at each distance. The centre non-transgenic circle was also sampled. Plants were grown from the seed samples and sprayed with glufosinate to estimate the frequency of pollen dispersal at each distance. In order to screen enough samples to detect low frequency cross-pollination events, seed samples were tested in the greenhouse and on a larger scale in the field. Results were confirmed by testing progeny for glufosinate resistance and by Southern blot analysis. The estimated percentage of pollen dispersal in the non-transgenic centre circle was 4.8%. The frequency was estimated to be 1.5% at a distance of 1 m and 0.4% at 3 m. The frequency decreased sharply to 0.02% at 12 m and was only 0.00033% at 47 m. No obvious directional effects were detected that could be ascribed to wind or insect activity. 相似文献
4.
Abstract. The olfactory orientation of adult cabbage seed weevils (Ceutorhynchus assimilis Payk.) from a distance of 20 m to extracts of oilseed rape (Brassica napus L.) was studied in the field using mark–release–recapture experiments. Male and female weevils dispersed upwind from the centre of a circular array of traps baited with Oilseed rape extracts. In the absence of host-plant odour, female weevils dispersed randomly, and male weevils downwind. Percentage recapture of weevils was significantly greater in traps baited with rape flower than rape leaf extracts. Significantly fewer weevils were recaptured in unbaited traps compared to traps baited with rape flower or leaf extracts. We suggest that seed weevils can use odour-mediated upwind anemotaxis to locate their host-plants from distances of at least 20 m. 相似文献
5.
Ingrid H. Williams David J.T. Frearson Hassan Barari & Alastair McCartney 《Entomologia Experimentalis et Applicata》2007,123(3):299-307
The direction of flight of natural populations of Phradis interstitialis (Thomson), Tersilochus obscurator Aubert (both Hymenoptera: Ichneumonidae), and Platygaster subuliformis (Kieffer) (Hymenoptera: Platygastridae), parasitoids of three crucifer‐specialist herbivores, to and from their hosts’ host plant [oilseed rape, Brassica napus L. (Brassicaceae)] was studied in the field within a heterogeneous arable environment. Double‐sided Malaise traps encircling a plot of winter oilseed rape (cultivar Lutin) were used to sample the parasitoids as they flew towards and away from the plot during spring and summer. Daily trap catch of parasitoids and trap air flow were compared using Spearman's rank correlation. For all 14 insect days analysed, and for each species, the correlations between daily catch of parasitoids into distal halves of traps (relative to the plot) and wind direction were negative, significantly so on half the days analysed. This confirmed that flights towards the plot were by upwind anemotaxis. In contrast, the correlations between daily catch of parasitoids into proximal halves of traps (relative to the plot) and wind direction were most often crosswind; they were never strongly nor significantly either negative or positive. Implications of the results for integrated pest management strategies incorporating biological control with these parasitoids are discussed. 相似文献
6.
Damage to oilseed rape seedlings by the field slug Deroceras reticulatum in relation to glucosinolate concentration 总被引:1,自引:0,他引:1
Seedlings of nine commercial cultivars of oilseed rape were exposed to the field slug Deroceras reticulatum immediately after sowing in compost in trays. There was a small reduction in seedling numbers in the presence of slugs which was not related to glucosinolate concentration in seeds or seedlings. However, the number and leaf-area of seedlings with damage symptoms were strongly and inversely related to the total concentration of glucosinolates in seeds and one wk-old seedlings. The presence of barley seedlings as alternative food did not significantly affect this relationship. The glucosinolate concentration of seeds was closely correlated with that of wk-old seedlings. Analysis of individual glucosinolates in four cultivars spanning the range of concentrations found, showed that the concentration of most components declined as total glucosinolate concentration decreased. However, 2-phenyl ethyl-glucosinolate (gluconasturtiin) concentration tended to increase in seeds and 3-indolyl methyl-glucosinolate (glucobrassicin) increased in seedlings as total glucosinolate concentration decreased. Damage by slugs was inversely related to the concentration of those glucosinolates which decreased and was positively correlated with the two compounds which increased as total glucosinolate concentration decreased. The results support the hypothesis that glucosinolates in brassicas protect them from polyphagous herbivores, and, in particular, that an important function of glucosinolates in rape seeds is to protect seedlings from slugs. As glucosinolate concentrations of oilseed rape cultivars continue to decline, so the risk of slug damage to seedlings may well increase. 相似文献
7.
Three-week-old shoots of the spring oilseed rape cv. Petranova ( Brassica napus L. ssp. napus ) were found by combined gas chromatography-mass spectrometry to contain GA1 , GA8 , GA15 , GA17 , GA19 , GA20 , GA24 , GA29 , 3-epi-GA1 and a previously uncharacterised C19 dicarboxylic acid that is probably structurally related to GA24 . Shoots of the winter cultivar Belinda, harvested at the early flowering stage, contained the same GAs with the exception of the C19 dicarboxylic acid and, in addition, GA34 and GA51 were identified. All material contained higher levels of GA20 than of GA1 ; the ratio of GA1 to GA20 was highest in shoots containing the largest proportion of young immature tissues. Soil treatment of cv. Petranova seedlings with the growth retardant BAS 111¨W [1-phenoxy-5,5-dimethyl-3-(1,2,4-triazol-1-yl)-hexan-4-ol] caused 80% reduction in height 18 days after treatment and the levels of all GAs were 20% or less that of control plants. Foliar treatment at the same dosage reduced height by 50% and caused an 85% or greater reduction in the concentrations of the GA1 precursors GA20 , GA19 and GA44 . However, the levels of GA1 , GA8 and GA29 were affected to a much smaller extent. Foliar application of BAS 111¨W to cv. Belinda 1 month after sowing resulted in only a 20% height reduction at flowering, but no uniform decrease in the concentrations of endogenous GAs at this stage. 相似文献
8.
Fengshan Pan Qian Meng Sha Luo Jing Shen Bao Chen Kiran Yasmin Khan 《International journal of phytoremediation》2017,19(3):281-289
Four plant growth-promoting bacteria (PGPB) were used as study materials, among them two heavy metal-tolerant rhizosphere strains SrN1 (Arthrobacter sp.) and SrN9 (Bacillus altitudinis) were isolated from rhizosphere soil, while two endophytic strains SaN1 (Bacillus megaterium) and SaMR12 (Sphingomonas) were identified from roots of the cadmium (Cd)/zinc (Zn) hyperaccumulator Sedum alfredii Hance. A pot experiment was carried out to investigate the effects of these PGPB on plant growth and Cd accumulation of oilseed rape (Brassica napus) plants grown on aged Cd-spiked soil. The results showed that the four PGPB significantly boosted oilseed rape shoot biomass production, improved soil and plant analyzer development (SPAD) value, enhanced Cd uptake of plant and Cd translocation to the leaves. By fluorescent in situ hybridization (FISH) and green fluorescent protein (GFP), we demonstrated the studied S. alfredii endophytic bacterium SaMR12 were able to colonize successfully in the B. napus roots. However, all four PGPB could increase seed Cd accumulation. Due to its potential to enhance Cd uptake by the plant and to restrict Cd accumulation in the seeds, SaMR12 was selected as the most promising microbial partner of B. napus when setting up a plant–microbe fortified remediation system. 相似文献
9.
Understanding patterns of pollen movement at the landscape scale is important for establishing management rules following the release of genetically modified (GM) crops. We use here a mating model adapted to cultivated species to estimate dispersal kernels from the genotypes of the progenies of male-sterile plants positioned at different sampling sites within a 10 x 10-km oilseed rape production area. Half of the pollen clouds sampled by the male-sterile plants originated from uncharacterized pollen sources that could consist of both large volunteer and feral populations, and fields within and outside the study area. The geometric dispersal kernel was the most appropriate to predict pollen movement in the study area. It predicted a much larger proportion of long-distance pollination than previously fitted dispersal kernels. This best-fitting mating model underestimated the level of differentiation among pollen clouds but could predict its spatial structure. The estimation method was validated on simulated genotypic data, and proved to provide good estimates of both the shape of the dispersal kernel and the rate and composition of pollen issued from uncharacterized pollen sources. The best dispersal kernel fitted here, the geometric kernel, should now be integrated into models that aim at predicting gene flow at the landscape level, in particular between GM and non-GM crops. 相似文献
10.
11.
S. M. Cook H. B. Rasmussen M. A. Birkett D. A. Murray B. J. Pye N. P. Watts I. H. Williams 《Arthropod-Plant Interactions》2007,1(1):57-67
There is increasing interest in the use of trap crops as components of integrated pest management (IPM) strategies. Understanding the mechanisms underlying host plant preferences of herbivorous pests can lead to improved effectiveness and reliability of the trap crop. We investigated the behavioural and chemical ecology underlying the success of turnip rape, Brassica rapa, trap crops in protecting oilseed rape, Brassica napus, from the pollen beetle, Meligethes aeneus, which feeds in the flowers and lays its eggs in the buds causing yield loss. Using a semi-field arena bioassay, plant growth stage was found to be a major factor in the preference of this pest for B. rapa over B. napus. Plants at early-flowering growth stages were preferred over plants in the bud stage, irrespective of species. No preference was found when both species were flowering. As B. rapa develops faster than B. napus in the field, this could explain part of the mechanism of its success as a trap crop. However, B. rapa was preferred over B. napus when both species were in the bud stage, indicating some inherent preferences for B. rapa. Responses of M. aeneus in olfactometer tests to the odours of B. napus and B. rapa at the bud and flowering growth stages, reflected those of the semi-field arena bioassay. These behavioural responses can be explained by volatile compounds associated with the flowering stage. Phenylacetaldehyde, indole and (E,E)-α-farnesene were found to be present in air entrainment samples of both plant species at the flowering growth stage, but only in those of B. rapa at the bud stage. The former two compounds were behaviourally-active in olfactometer tests. These compounds are likely to be involved in host location by M. aeneus, and, at least partially, responsible for the attractiveness of B. rapa and its success as a trap crop to protect B. napus from this pest. 相似文献
12.
ABSTRACT. Movement of host odour was modelled in natural tsetse habitats with smoke and ultra-light 7-cm-long wind vanes; the speed and direction of the air movements were analysed from video recordings thereof. Wind of <1 ms-1 did not move in straight lines, since large packets of air (>10 m across) often changed direction together. The rate of this change of direction (meander) correlated negatively with windspeed. In open woodland with a shrubby understorey (in which windspeed was reduced by a factor of >5 from that above the canopy, to ax 0.3 m s-1), this wind meander fell by 2d? s-1 change of direction for each 0.1 m s-1 increase in windspeed (r2=0.96). Over open ground without shrub cover, the meander fell by 0.5d? s-1 per 0.1 m s-1 increase in windspeed (r2=0.85). In both situations, such meandering virtually ceased in winds of > 1 m s-1. In woodland, the relationship between the direction of air movement near the surface of bare earth (one potential tsetse landing site) and that c. 0.5 m above ground level (flight height) was often weak (r2=0.2-0.4), but this problem would be reduced if the fly averaged the ground-level wind for at least 30 s. Odour (smoke) travelling from a source 15 m ‘upwind’ over open ground arrived at a notional tsetse fly for 80% of the time from a direction within 10d? of the true source direction. In typical tsetse woodland, however, the ‘odour’ arrived from all directions (including >90d? away from the source), with only a 30% bias towards the true source direction (±10d?). Evidently, tsetse must navigate up odour plumes by means that get round these difficulties-simple, moth-type upwind anemotaxis alone seems unlikely to be adequate. 相似文献
13.
Cold-deacclimation of oilseed rape (Brassica napus var. oleifera) in response to fluctuating temperatures and photoperiod 总被引:2,自引:0,他引:2
Rapacz M 《Annals of botany》2002,89(5):543-549
The aim of this work was to establish the role of factors that may trigger elongation growth in the dehardening response, namely temperature during daylight, photoperiod and vernalization. Fully cold-acclimated seedlings of winter (with incomplete vernalization) and spring oilseed rape were subjected to deacclimation under temperatures of 2/12, 12/2, 12/12, 12/20, 20/12 and 20/20 degrees C (day/night) and a 12 h photoperiod. Plants were also deacclimated under photoperiods of 8 and 16 h at constant temperatures of 12 and 20 degrees C. After deacclimation, plants were subjected to reacclimation. Results suggest that the level of growth activity induced during deacclimation affects both the deacclimation rate and the capacity for reacclimation. Deacclimation is fully reversible if it is not accompanied by induction of elongation growth. In such cases the rate of the decrease in freezing tolerance depends on the mean temperature of deacclimation. Deacclimation becomes partially or completely irreversible when it is connected with promotion of elongation growth. The stimuli triggering elongation growth during deacclimation may be the growth-promoting temperature (20 degrees C) during the day and the lack of vernalization blockage of elongation growth. When elongation growth was stimulated by other factors such as long-day treatments, rehardening was also disturbed. 相似文献
14.
Mechanical wounding of the petioles of six laboratory-grown rapeseed ( Brassica napus ) cultivars induced physiological changes in the plant, markedly affecting the levels of individual glucosinolates. Greatest increases were observed for the indole glucosinolates, glucobrassicin and neoglucobrassicin. Such changes were usually associated with large decreases in the levels of aliphatic glucosinolates. The total glucosinolate content of the wounded plant was thus a reflection of these two opposing trends and wounding produced a greater relative indole glucosinolate content in this total figure. Thus increasing wounding was associated with an increase in indole glucosinolates and a decrease in aliphatic compounds.
Infestation of field- and laboratory-grown rapeseed with cabbage stem flea beetle ( Psylliodes chrysocephala ) produced similar effects, which were observed in various parts of the plant. Differences in response between field- and laboratory-grown infested plants are attributed to the different physiological ages of the harvested material.
Laboratory-grown kale and mustards also showed wound-induced glucosinolate changes. The kale, cv. Fribor, produced elevated levels of both indoles and aliphatics after wounding. Total glucosinolate content in the mustards, which, unlike rape and kale, normally contain only traces of indole glucosinolates in the unstressed state, was increased following wounding. This was, however, not associated with elevated levels of indole glucosinolates, but with accumulation of aliphatic ( Brassica nigra, B. juncea ) and aromatic ( Sinapis alba ) glucosinolates. The significance of these findings is discussed. 相似文献
Infestation of field- and laboratory-grown rapeseed with cabbage stem flea beetle ( Psylliodes chrysocephala ) produced similar effects, which were observed in various parts of the plant. Differences in response between field- and laboratory-grown infested plants are attributed to the different physiological ages of the harvested material.
Laboratory-grown kale and mustards also showed wound-induced glucosinolate changes. The kale, cv. Fribor, produced elevated levels of both indoles and aliphatics after wounding. Total glucosinolate content in the mustards, which, unlike rape and kale, normally contain only traces of indole glucosinolates in the unstressed state, was increased following wounding. This was, however, not associated with elevated levels of indole glucosinolates, but with accumulation of aliphatic ( Brassica nigra, B. juncea ) and aromatic ( Sinapis alba ) glucosinolates. The significance of these findings is discussed. 相似文献
15.
The effects of the acylcyclohexanedione-type growth retardant prohexadione calcium on seedling growth and endogenous levels of immunoreactive phytohormone-like substances in shoots of wheat ( Triticum aestivum L. cv. Kanzler) and oilseed rape ( Brassica napus L. ssp. napus cv. Lirajet) were studied. After treatment of seedlings with increasing retardant concentrations in hydroponics, plant height and fresh weight of shoots were reduced by up to 40%. Concomitantly, the amount of immunoreactive gibberellins decreased, on a fresh weight basis, when compared with levels in the shoots of control plants. In contrast, the levels of abscisic acid and dihydrozeatin riboside and isopentenyladenosine-type cytokinins were considerably elevated by the growth retardant. The content of 3-indoleacetic acid decreased slightly. These results suggest that, in addition to its effect on gibberellin content, prohexadione calcium also influences the levels of endogenous abscisic acid and cytokinins. 相似文献
16.
E. Bartlet M. M. Blight P. Lane I. H. Williams 《Entomologia Experimentalis et Applicata》1997,85(3):257-262
The cabbage seed weevil, Ceutorhynchus assimilis Payk. [syn. Ceutorhynchus obstrictus (Marsham)] (Coleoptera: Curculionidae), a crucifer-feeding insect, is a pest of oilseed rape (Brassica napus L.). It is known to be attracted by isothiocyanates, crucifer-specific volatiles that are metabolites of the glucosinolates. The responses of this insect to other electrophysiologically-active volatiles from rape were tested in a linear track olfactometer. Attraction was demonstrated to nitriles (phenylacetonitrile, 4-pentenenitrile and 5-hexenenitrile), which are also glucosinolate metabolites, and to volatiles emitted by a wider spectrum of plant families ((Z)-3-hexen-1-ol and methyl salicylate). Combination of an isothiocyanate mixture with phenylacetonitrile increased attraction, but there was no such increase when the isothiocyanate mixture was combined with methyl salicylate. A mixture of 23 volatiles, emulating an attractive air-entrainment extract of oilseed rape, was not significantly attractive, although a high proportion of weevils (60%) turned towards it. The potential of these volatiles for inclusion into an isothiocyanate-based monitoring system is discussed. 相似文献
17.
The carabid beetles Amara similata and Poecilus cupreus are abundant in Central European winter oilseed rape (OSR) fields and potential antagonists of OSR pests. Therefore, they were investigated in 29 OSR fields relative to the influence of field and landscape parameters on their nutritional condition, reproductive potential and activity density. Nutritional condition was measured by a condition factor (CF). Fecundity of female beetles was expressed by the number of ripe oocytes in the ovaries. Activity density comprised the number of individuals caught with pitfall traps during their peak of reproductive period. Soil productivity and pest abundance (as a proxy of local prey availability) were considered as field parameters. Landscape parameters comprised the distance to the next fallow and the percentage of crop area around each study field. In eight of ten cases, pest abundance proved to be the most important factor explaining carabid characteristics, indicating that P. cupreus and A. similata consume insect pests in OSR fields. Pest abundance influenced the CF of both species and sexes positively. Oocyte numbers of A. similata were negatively related to the distance to the next fallow. Oocyte numbers of P. cupreus tended to increase with increasing pest abundance. Activity density of female A. similata was negatively influenced by soil productivity. Activity density of male A. similata and of female and male P. cupreus was negatively influenced by pest abundance. When analysing exclusively the influence of severe OSR pests (Meligethes aeneus, Ceutorhynchus napi and Dasineura brassicae), abundance of larval M. aeneus and C. napi was most important in explaining the CF and activity density of male A. similata, and male and female P. cupreus. M. aeneus and C. napi could be an essential prey for the carabids studied which may reduce the pests, thereby contributing to the protection of OSR from pest herbivory. 相似文献
18.
Alice L. Mauchline Michael A. Birkett Christine M. Woodcock John A. Pickett Juliet L. Osborne Wilf Powell 《Arthropod-Plant Interactions》2008,2(2):109-115
A semiochemical based push-pull strategy for control of oilseed rape pests is being developed at Rothamsted Research. This
strategy uses insect and plant derived semiochemicals to manipulate pests and their natural enemies. An important element
within this strategy is an understanding of the importance of non-host plant cues for pest insects and how such signals could
be used to manipulate their behaviour. Previous studies using a range of non-host plants have shown that, for the pollen beetle
Meligethes aeneus (Coleoptera: Nitidulidae), the essential oil of lavender, Lavandula angustifolia (Lamiaceae), was the most repellent. The aim of this study was to identify the active components in L. angustifolia oil, and to investigate the behaviour of M. aeneus to these chemicals, to establish the most effective use of repellent stimuli to disrupt colonisation of oilseed rape crops.
Coupled gas chromatography-electroantennography (GC-EAG) and gas chromatography-mass spectrometry (GC-MS) resulted in the
identification of seven active compounds which were tested for behavioural activity using a 4-way olfactometer. Repellent
responses were observed with (±)-linalool and (±)-linalyl acetate. The use of these chemicals within a push-pull pest control
strategy is discussed.
Handling Editor: Yvan Rahbe. 相似文献
19.
Abstract Changes in the net uptake rate of K+ and in the average tissue concentration of K+ were measured over 14 d in response to changes in root temperature with oilseed rape (Brassica napus L. cv. Bien venu) and barley (Hordeum vulgare L. cv. Atem). Plants were grown in flowing nutrient solutions containing 2.5 mmol m?3 K+ and were acclimatized over 49 d (rape) or 28 d (barley) to low root temperature (5°C) prior to steady–state treatments at root temperatures between 3 °C and 25 °C, with common air temperature. Uptake of K+ was monitored continuously over 14 d and nitrogen was supplied as NH4++ NO?3 or NH+4 or NO?3. Unit absorption rates of K+ increased with time and with root temperature up to Day 4 or 5 following the change in root temperature. Thereafter they usually approached steady-state, with Q10? 2.0 between 7 °C and 17°C, although rates became similar between 7 °C and 13°C. Uptake of K+ by rape plants was invariably greater under NO?3 nutrition compared with NH+4. The percentage K+ in the plant dry matter increased with temperature from 2% at 3 °C to 4% at 25 °C in rape, but there was less effect of temperature on the average concentrations of K+ in the plant fresh weight or plant water content. Concentrations of K+ in the leaf water fraction of rape plants decreased with increasing root temperature, but in barley they increased with increasing root temperature. Concentrations of K+ in the root water fraction were relatively stable with respect to root temperature. The results are discussed in terms of compensatory changes in K+ uptake following a change in root temperature and the relationships between growth, shoot: root ratio and K+ composition of the plant. 相似文献
20.
E. Bartlet M. M. Blight A. J. Hick I. H. Williams 《Entomologia Experimentalis et Applicata》1993,68(3):295-302
The responses of the cabbage seed weevil,Ceutorhynchus assimilis Payk. (Coleoptera: Curculionidae) to volatiles from oilseed rape (Brassica napus L.) were tested using a linear track olfactometer. Weevils were attracted towards the odour of rape during a short period
before diapause and for most of their postdiapause life. Odours from both the flowering and green parts of the plant were
attractive, but the odour of a non-host plant (Bellis perennis L.) was not. An entrainment extract of flowering rape volatiles in pentane was attractive, but significantly less so than
the odour of flowering rape itself. Attraction was found to 3-butenyl and 4-pentenyl isothiocyanate (NCS), but not to 2-phenylethyl
isothiocyanate. A mixture of the three NCSs was more attractive than the individual NCSs. However, the concentration required
to produce a response was still relatively high. Isothiocyanates, along with other volatiles from rape, probably play a role
in host plant recognition by the seed weevil. 相似文献