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1.
Male white-spotted longicorn beetles Anoplophora malasiaca raised on willow Salix schwerinii were preferentially attracted to the odour of wounded S. schwerinii branches when released near a female model in the laboratory. This attractiveness rapidly decreased within 2 h after wounding.
Solid phase microextraction and subsequent gas chromatography analyses of volatiles from the wounded branches detected three
highly volatile monoterpenes: 1,8-cineole, nerol and geraniol. Among the monoterpene compounds, nerol showed a significant
attractiveness to the male beetles raised on Salix. Sesquiterpene hydrocarbons, which have been identified as attractants for a beetle population raised on citrus, were detected
only in trace amounts in S. schwerinii branches. These results suggest that beetles raised on these two hosts use different odour cues for mate location. 相似文献
2.
To better understand the attractiveness of host tree, Chinese white pines (Pinus armandi Fr.) to Chinese white pine beetle (Dendroctonus armandi Tsai and Li), the antennal responses of D. armandi to the host volatile, as well as the pure enantiomers and racemates of some monoterpenes, were examined using an electroantennogram
(EAG). EAG responses of male and female D. armandi to blended volatiles extracted from the host and some synthetic terpenes (α-phellandrene, (−)-β-pinene, (+)-α-pinene, (−)-α-pinene,
(−)-camphene, β-myrcene, (S)-(−)-limonene, (+)-camphene and (R)-(+)-limonene) showed significant variation due to different compound concentrations and sex of the beetles. EAG responses
to extracted blended volatiles were significantly greater in females than in males, but the EAG response was not always proportional
to the volatile concentration. At lower concentrations, females responded strongly to α-phellandrene and males to (−)-β-pinene,
while at higher concentrations, females responded most strongly to α-phellandrene and males to (+)-α-pinene. Females were
significantly responsive to (−)-α-pinene, α-phellandrene and (−)-camphene, while males were more responsive to (S)-(−)-limonene, (+)-α-pinene and (R)-(+)-limonene. The EAG responses of the female D. armandi to the volatile oil were significantly higher than that of the males, and the infested pine volatiles could evoke higher
EAG response. Most of the test compounds elicited similar responses, which suggested that several of the compounds may be
used in combination by D. armandi in habitat and/or host community location at the Qinling forest ecosystem. 相似文献
3.
Summary. Using Porapak Q traps, we collected the bark volatiles of six angiosperm trees native to British Columbia: black cottonwood,
Populus trichocarpa Torr. & A. Gray (Salicaceae), trembling aspen, P. tremuloides Michx. (Salicaceae), paper birch, Betula papyrifera Marsh. (Betulaceae), bigleaf maple, Acer macrophyllum Pursh (Aceraceae), red alder, Alnus rubra Bong. (Betulaceae), and Sitka alder, A. viridis ssp. sinuata (Regel) á. L?ve & D. L?ve (Betulaceae). Utilising coupled gas chromatographic-electroantennographic detection analysis, the
captured volatiles were assayed for antennal responses in five species of coniferophagous bark beetles (Coleoptera: Scolytidae),
sympatric with most or all of the angiosperm trees: the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, the mountain pine beetle, D. ponderosae Hopkins, the spruce beetle, D. rufipennis (Kirby), the western balsam bark beetle, Dryocoetes confusus Swaine, and the pine engraver, Ips pini (Say). The identities of 25 antennally-active compounds were determined by coupled gas chromatographic-mass spectroscopic
analysis, and co-chromatographic comparisons with authentic chemicals. The compounds identified were: hexanal, (E)-2-hexenal, (Z)-3-hexen-1-ol, 1-hexanol, heptanal, α-pinene, frontalin, benzaldehyde, β-pinene, 2-hydroxycyclohexanone, 3-carene, limonene,
β-phellandrene, benzyl alcohol, (E)-ocimene, salicylaldehyde, conophthorin, guaiacol, nonanal, methyl salicylate, 4-allylanisole, decanal, thymol methyl ether,
(E)-nerolidol, and dendrolasin. A number of these compounds are known semiochemicals that are active in the behaviour of other
organisms, including bark beetles, suggesting a high degree of semiochemical parsimony. Antennally-active compounds ranged
from seven in A. viridis to 17 in P. trichocarpa. The fewest number of compounds (9) were detected by I. pini and the largest number (24) were detected by D. pseudotsugae. Six compounds excited the antennae of all five species of bark beetles. The large number of antennally-active compounds
detected in common by numerous bark beetles and present in common in numerous nonhost trees supports the hypothesis of olfaction-based
recognition and avoidance of nonhost angiosperm trees during the process of host selection by coniferophagous bark beetles.
Received 13 December 1999; accepted 14 March 2000 相似文献
4.
Anne Lyytinen Leena Lindström Johanna Mappes Riitta Julkunen–Tiitto Sergey R. Fasulati Kari Tiilikkala 《Chemoecology》2007,17(1):51-56
Summary. Many studies investigating effects of plant chemicals on herbivore performance have reported contradictory results, perhaps
because of possible interaction between different chemicals. Also, a herbivore’s performance is not necessarily consistent
with its food or oviposition preference. Our aim was to investigate simultaneously antibiosis (larval growth and survival)
and antixenosis (oviposition and feeding preferences) responses in herbivore to three plant chemicals, of which one is expected
to have positive and two are expected to have negative effects. Antibiosis was measured by correlating the nitrogen and glycoalkaloid
levels in host plants to the survival and adult size of Leptinotarsa decemlineata, by rearing larvae on whole plants of three potato varieties. Although host plants differed in their glycoalkaloid levels,
survival rate and adult body size did not differ among beetles reared on different potato varieties. This suggests that beetles
are quite robust for differences in both foliar α-chaconine and foliar α-solanine content. However, differences in antixenosis
were found although they could not be directly predicted from the leaf chemistry. Females preferred to lay their eggs on the
variety with high α-solanine content (Nevsky) towards which males showed a tendency to feeding preference. Overall, our results
confirm that beetles are well adapted to the chemical defences of potato plants as potato varieties did not significantly
affect beetle performance, but differences in oviposition preference may still result in major differences in the amount of
damage inflicted on plants in the fields. 相似文献
5.
Summary. Several species of the flea beetles genus Longitarsus are able to sequester pyrrolizidine alkaloids (PAs) from their host plants. In five Longitarsus species we compare the concentration of PAs present in their host plants belonging to the Asteraceae or Boraginaceae with
those found in the beetles. To get an estimate of the intrapopulation variability, three samples of five beetles each and
five individual plants were analyzed for each comparison. A strong intrapopulation variability could be detected both among
plant and beetle samples. The total concentration found in the beetles varied strongly between species. The local host plant
and its phenology influence the concentrations present in the beetles as evidenced in comparisons of a single beetle species
from two different hosts and of one beetle species collected at the same site at different times of the year. In addition,
different beetle species apparently vary in their capacity to sequester the alkaloids, at the lowest extreme the mean PA concentration
in the beetles (0.034 μg PA/mg dry weight) was 1/30 of the mean concentration found in the plant leaves (L. aeruginosus from Eupatorium cannabinum), at the highest extreme (2.098 μg PA/mg dw) the concentration in the beetles was a 1000 fold higher than in the plant leaves
(L. nasturtii from Symphytum officinale). The highest mean concentration found in the beetles was 3.446 μg/mg dw (L. exoletus from Cynoglossum officinale). The absolute concentrations found in the beetles are comparable to other insects which have been shown to be effectively
defended against their potential predators.
Received 22 June 1999; accepted 25 August 1999 相似文献
6.
Adult Anoplophora malasiaca beetles were collected from field populations inhabiting three different host plants: Citrus, Salix and Vaccinium. Male orientation responses towards odours of wounded branches of each host plant were examined. Males of all three populations were attracted most frequently to odours of their original hosts, indicating that male orientation behaviour was induced by the odours of the plants from which they were originally collected. We also observed the mating responses of the males to elytra extracts from young and mature females of the three populations and chemically analysed those extracts. Citrus males were highly responsive to female extracts, regardless of origin. Salix males were less reactive than Citrus males, but responded moderately to female extracts of all populations. Vaccinium males were never attracted to Citrus female extracts and responded more to extracts from mature Vaccinium and Salix females, indicating that males might distinguish female origin and maturity. All eight hydrocarbons, four ketones, and three lactones that were previously identified as female contact sex pheromones were found in the extracts of three populations and both ages. Higher amounts of lactones on mature females likely caused greater male responses. These results suggested that males would be more likely to approach a female feeding on the same host plant and subsequently recognise her sexual maturity based on the profile of contact sex pheromones on her elytra. 相似文献
7.
Summary. Host selection in tree-killing bark beetles
(Coleoptera: Scolytidae) is mediated by a complex of semiochemical
cues. Using gas chromatographic-electroantennographic
detection (GC-EAD) and GC-mass spectrometric
analyses, we conducted a comparative study of the electrophysiological
responses of four species of tree-killing bark
beetles, the Douglas-fir beetle, Dendroctonus pseudotsugae,
Hopkins, the mountain pine beetle, D. ponderosae Hopkins,
the spruce beetle, D. rufipennis Kirby, and the western balsam
bark beetle, Dryocoetes confusus Swaine, to volatiles
captured by aeration of 1) bole and foliage of four sympatric
species of conifers, Douglas-fir, Pseudotsuga menziesii
(Mirb.) Franco, lodgepole pine, Pinus contorta var. latifolia
Engelm., interior spruce, Picea engelmannii x glauca, and
interior fir, Abies lasiocarpa x bifolia, and 2) con- and
heterospecific beetles at three stages of attack. We identified
13 monoterpenes in the conifers and nine compounds in the
volatiles of beetles that elicited antennal responses. There
was no qualitative difference in the terpene constitution of
the four species of conifers and very little difference across
beetle species in their antennal response to compounds from
conifers or beetles. The lack of species-specific major or
minor components in conifers suggests that beetles would
need to detect differences in the ratios of different compounds
in conifers to discriminate among them. Attraction to
hosts and avoidance of nonhost conifers may be accentuated
by perception of compounds emitted by con- and heterospecific
beetles, respectively. The 22 compounds identified
are candidate semiochemicals with potential behavioural
roles in host location and discrimination. 相似文献
8.
Summary. Ponderosa pine, Pinus ponderosa Laws. (Pinaceae), forests in Arizona have suffered from a nine-year period of drought and bark beetle, Ips lecontei Swaine (Coleoptera: Scolytidae), outbreaks. Abiotic and biotic stress in ponderosa pine results in the induced synthesis
of certain monoterpenes that may in turn affect bark beetle behavior and survival. In this study, we investigate whether induced
monoterpene production could result in a different monoterpene composition that remains stored in the needles or the trunk
resin of the tree. Needle and resin samples in addition to trunk cores were collected from ponderosa pines at three locations
in Arizona. Ungulate browsing induced a significant increase in limonene (P=0.010) and in chemodiversity (P=0.009), a measure
of the evenness of distribution among the monoterpenes present in needles. We compared the level of ‘stress’ of the trees
by measuring the thickness of annual rings in living trees and those that were killed by bark beetles. Where drought occurred,
the spacing of annual rings from the last 10 years of trees killed by bark beetles was significantly smaller (P=0.020) compared
to living trees. There was no difference in the monoterpene composition between the core sections of closest spacing of annual
rings (stressed years) compared to the sections of widest spacing, which indicates that monoterpenes are distributed evenly
throughout the extended resin system. In the area where the degree of drought was less overall, none of the individual monoterpenes
present in the resin was related to bark beetle killed trees. However, about half the living pines had resin in which one
of the major monoterpenes (α-pinene, Δ3-carene, and limonene) was absent, and these trees had a lower monoterpene chemodiversity compared to trees killed by bark
beetles. Trees with these three major monoterpenes, corresponding to the average relative proportion in living pines at that
location, may sustain higher selection and colonization by bark beetles. 相似文献
9.
Summary. The pollen beetle, Meligethes aeneus, is an important pest of oilseed rape, Brassica napus. Larvae of this species feed only in the buds and flowers of Brassicaceae. One important natural enemy of this beetle is
the parasitoid Phradis morionellus that attacks larvae in buds and flowers and also feeds on the flowers. The preferences for odours of non-infested and infested
rape were tested for both starved and fed parasitoids in Y-tube olfactometer experiments. The volatile blend released from
pollen beetle-infested and non-infested flowering rape and from pollen beetle larvae was identified and quantified. Gas chromatography-electroantennodetection
analyses were performed with female P. morionellus. Parasitoids in both treatment groups preferred infested rape, but the proportion of responding female P. morionellus was significantly lower for the group that was starved. Six of the 20 volatiles identified were released at higher rates
from infested rape than from non-infested. None of these compounds was found in pollen beetle larvae headspace. P. morionellus antennae detected both major and minor components in the volatile blend. The volatiles released at a significantly higher
rate from infested rape and detected by P. morionellus antennae were (Z)-3-hexenylacetate, (Z)-3-hexenol, 3-butenyl isothiocyanate and (E,E)-α-farnesene. 相似文献
10.
New repellent semiochemicals for three species of
<Emphasis Type="Italic">Dendroctonus</Emphasis> (Coleoptera: Scolytidae) 总被引:1,自引:0,他引:1
Summary. Nine compounds identified from captured
volatiles of the Douglas-fir beetle, Dendroctonus pseudotsugae,
the mountain pine beetle, D. ponderosae, and the
spruce beetle, D. rufipennis, that elicited antennal responses
in males and females of one or more of these species were
tested in the field to determine behavioural activity.
1-Octen-3-ol, found in the volatiles of females of all three
species decreased the response of male and female coastal
and male interior D. pseudotsugae and both sexes of D. ponderosae
to their aggregation pheromones. Acetophenone,
identified in the volatiles of females of all three species,
significantly decreased the response of interior female
D. pseudotsugae. trans-Verbenol, a potent aggregation
pheromone of D. ponderosae, decreased the response of both
sexes of D. pseudotsugae, while 3-methyl-2-cyclohexen-1-
one (MCH), the antiaggregation pheromone of D. pseudotsugae
and D. rufipennis decreased the response of both sexes
of D. ponderosae. While it has been demonstrated that semiochemical
mediated interspecific communication occurs
among bark beetles infesting the same host, this study
demonstrates that beetles can perceive signals emitted by
heterospecifics attacking nonhosts and can potentially use
them to avoid attacking the wrong species of conifer. 相似文献
11.
Summary. The leaf beetle Ophraella communa infests
almost exclusively Ambrosia artemisiifolia in the fields of
Japan, even though it normally feeds on several Asteraceous
plants. A filter paper bioassay showed that the feeding of
O. communa is strongly stimulated by methanolic extracts of
A. artemisiifolia. The feeding stimulants for O. communa have
been isolated from methanolic extracts of A. artemisiifolia.
-Amyrin acetate, -amyrin acetate, 5-caffeoylquinic acid
(chlorogenic acid) and 3,5-dicaffeoylquinic acid from
A. artemisiifolia have been identified as feeding stimulants
for O. communa. Triterpenoid derivatives
(-amyrin acetate or -amyrin acetate) and caffeic acid derivatives (3,
5-dicaffoylquinic acid or 5-caffeoylquinic acid) showed
feeding stimulant activity when mixed together. 相似文献
12.
In many vertebrates, environmental factors influence gamete differentiation and growth of the mature gonad through alteration
of sex steroid production or action; however, it is unclear how gamete differentiation and gonadal growth are regulated in
echinoids. The purpose of this study was to examine the influence of dietary administration of estradiol (E2), progesterone
(P4), testosterone (T) and finasteride (F, a 5α-reductase inhibitor) on the ovaries and testes of mature Lytechinus variegatus (Lamarck) during gonadal growth. Echinoids were fed a formulated diet supplemented with steroids or steroids in combination
with finasteride for 36 d. The effects of dietary administration of steroids on L. variegatus were both steroid- and sex-specific. The mean ovary index was 54% greater in individuals fed E2 than from individuals fed
the control (C) diet (10.0 ± 1.1 vs 6.5 ± 0.7, respectively; P < 0.05). Individuals fed E2, P4, E2/P4, and P4 in combination with F had significantly smaller oocytes (P < 0.005) than individuals fed C. The volume fraction occupied by nutritive phagocytes in ovarian tubules from individuals
fed E2/P4 or P4 were significantly larger than the volume fraction occupied by nutritive phagocytes from individuals fed C,
indicating that E2 and 5α-reduced progestins may promote nutrient allocation to nutritive phagocytes. Although oocytes from
the individuals fed T alone were significantly smaller than those fed T in combination with F, oocytes from individuals in
both treatments were significantly larger compared to oocytes from individuals fed C. These data suggest that upon removal
of 5α-reduced androgens, T is able to promote an increase in oocyte diameters. In contrast, the mean testis index was 56%
greater in individuals fed P4 than in individuals fed C (8.9 ± 0.6 vs 5.7 ± 0.9, respectively; P < 0.05); the testis index did not increase in individuals fed P4/F, suggesting that 5α-reduced progestins stimulate testicular
growth. Testes growth in the presence of 5α-reduced progestins was accomplished by significant increases in the volume fraction
occupied by nutritive phagocytes and by a significant reduction in the volume fraction occupied by spermatogenic columns in
testicular tubules. These data further indicate that 5α-reduced progestins (or 5α-reduced androgens) may inhibit spermatogenic
column formation. In conclusion, E2 stimulated ovarian growth but inhibited oocyte growth, whereas T had no affect on ovarian
growth but promoted oocyte growth in L. variegatus. We hypothesize that the E2 (or E2 metabolites) and/or 5α-reduced androgens in combination with T regulate oocyte growth
in the echinoid L. variegatus. In addition, 5α-reduced progestins promoted nutrient accumulation in nutritive phagocytes within the ovaries and the testes.
Furthermore, 5α-reduced progestins stimulated growth of the testes and inhibited spermatogenic column formation, suggesting
that 5α-reduced progestins regulate nutrient accumulation into nutritive phagocytes and spermatogenic column formation in
L. variegatus. The differences in estrogen effects between echinoids and asteroids may be related to differences in gonad morphology and,
ultimately, the differences in cellular signalling pathways (paracrine vs endocrine).
Received: 22 May 1999 / Accepted: 24 May 2000 相似文献
13.
Klaus Peschke Peter Friedrich Uwe Kaiser Stephan Franke Wittko Francke 《Chemoecology》1999,9(2):47-54
Summary. In the rove beetle Aleochara curtula, a male specific sternal gland is described. Isopropyl (Z9)-hexadecenoate has been identified by GC/MS of surface and sternal gland extracts as a male specific compound. Its emission
in the air was demonstrated by closed-loopstripping-analyses. In field experiments, conspecific males and females were attracted
by the odor of carrion, caged males from laboratory cultures, and by the synthetic ester. Isopropyl (Z9)-hexadecenoate or live males, combined with fresh carrion attract more beetles than a fresh carcass alone. Isopropyl hexadecanoate
as a minor compound was not attractive. The term “aggregation” pheromone and the ecological significance of attracting females
to a fresh carcass allowing early copulation and egg-deposition are discussed.
Received 20 August 1998; accepted 15 January 1999. 相似文献
14.
Summary.
Metrius contractus, a primitive paussoid bombardier beetle, emits its defensive quinonoid froth with accompanying sound (a faint “hiss”), but
the sound is not pulsed, indicating that the secretory emission itself is not pulsed. Pulsed secretory delivery in bombardier
beetles appears to occur in Brachinini only.
Received 8 July 2001; accepted 23 July 2001. 相似文献
15.
In vitro reporter gene assays using vertebrate cell lines or yeast have been used for assessment of the estrogenic chemicals.
However, estrogen receptor α (ERα)- and ERβ-mediated reporter gene system in fish has yet to be developed. In the present
study, we developed an ERα- and ERβ-mediated reporter gene assay in fish and estimated estrogenic activities of 17β-estradiol
(E2), p-nonylphenol (NP), bisphenol A (BPA), p,p′-DDE, and genistein (Gen) using the in vitro reporter assay. The activity was intensely induced by transfection with either
ERα or ERβ expression plasmid under E2 or Gen administration, whereas it was significantly induced by transfection with ERα
expression plasmid, but not with ERβ expression plasmid under NP administration. On the other hand, the activity was induced
more intensely by transfection with ERα expression plasmid than ERβ expression plasmid under BPA or p,p′-DDE administration. These results indicate that there are obvious differences in the activity through ERα and ERβ among
the estrogenic chemicals examined in vitro. Thus, the in vitro reporter assay provides an excellent system for elucidating
the action mechanism of estrogenic chemicals in fishes.
Physical and Chemical Impacts on Marine Organisms, a Bilateral Seminar Italy–Japan held in November 2004 相似文献
16.
Peter H. W. Biedermann Kier D. Klepzig Michael Taborsky 《Behavioral ecology and sociobiology》2011,65(9):1753-1761
Body reserves may determine the reproductive output of animals, depending on their resource allocation strategy. In insects,
an accumulation of reserves for reproduction is often obtained before dispersal by pre-emergence (or maturation) feeding.
This has been assumed to be an important cause of delayed dispersal from the natal nest in scolytine beetles. In the cooperatively
breeding ambrosia beetles, this is of special interest because in this group delayed dispersal could serve two alternative
purposes: “selfish” maturation feeding or “altruistic” alloparental care. To distinguish between these two possibilities,
we have experimentally studied the effect of delayed dispersal on future reproductive output in the xyleborine ambrosia beetle
Xyleborus affinis. Females experimentally induced to disperse and delayed dispersing females did not differ in their body condition at dispersal
and in their founding success afterwards, which indicates that females disperse independently of condition, and staying adult
females are fully mature and would be able to breed. However, induced dispersers produced more offspring than delayed dispersers
within a test period of 40 days. This suggests that delayed dispersal comes at a cost to females, which may result primarily
from alloparental care and leads to a reduced reproductive output. Alternatively, females might have reproduced prior to dispersal.
This is unlikely, however, for the majority of dispersing females because of the small numbers of offspring present in the
gallery when females dispersed, suggesting that mainly the foundress had reproduced. In addition, “gallery of origin” was
a strong predictor of the reproductive success of females, which may reflect variation in the microbial complex transmitted
vertically from the natal nest to the daughter colony, or variation of genetic quality. These results have important implications
for the understanding of proximate mechanisms selecting for philopatry and alloparental care in highly social ambrosia beetles
and other cooperatively breeding arthropods. 相似文献
17.
Alexandra Bottcher Jorge Paulo Zolin Flávia Nogueira-de-Sá José Roberto Trigo 《Chemoecology》2009,19(1):63-66
The most frequently investigated defence mechanism among larvae of tortoise beetles is protection by faecal shields, which
generally present chemicals that are directly sequestered and/or modified from larval host-plants. In the present work we
investigate the tortoise beetle Chelymorpha reimoseri that feeds on the leaves of Ipomoea carnea fistulosa (Convolvulaceae), seeking for the importance of this mechanism to their larvae. We show that 4th instar larvae suffer low
predation regardless of the presence of shields in field and laboratory bioassays with ants and chicks. Chloroform extract
from larvae without shields provided high protection against predation as shown in bioassays in the field, as well as against
chicks, suggesting that C. reimoseri does not rely on the shield for protection. The aqueous extract of the shields did not show activity in such bioassays. The
compounds responsible for this protection have yet to be identified, and it remains an open question as to whether they are
sequestered from the host plant or de novo biosynthesized. This is the first record of chemical defence in cassidine beetles
without the need for faecal shields. These findings indicate that more attention should be paid to chemicals present in the
tissues of larvae and/or adults of tortoise beetles; the protective compounds sequestered from host plants or de novo biosynthesized
can provide an alternative or complementary strategy against predation in these insects. 相似文献
18.
Based on carbohydrate histochemistry, including the use of lectins, and TEM, the study describes the distribution of terminal sugars in different structures of the demosponge Chondrilla nucula. The results of the general and specific carbohydrate histochemical approaches confirmed the presence of acidic and neutral glycoconjugates in the cells, and, with declining amounts from the ectosome to the mesohyl, in the extracellular matrix (ECM). AB-PAS staining indicated acidic complex carbohydrates particularly in the exopinacoderm, and more neutral ones in the cells and the ECM of the mesohyl. The PO-lectins applied demonstrated a general spectrum of free saccharide residues (α-d-mannose, α-/β-d-N-acetylglucosamine, α-d-N-acetylgalactosamine, α-d-galactose, β-d-galactose) in both sponge parts; α-l-fucose was only distinct in the ectosome. Sialic acids [siaα(2,3)-galactose, siaα(2,6)-N-acetylgalactosamine] were dominant in the very thin exopinacoderm, indicating O-linked high molecular weight glycoproteins. In this way a glycophysiologically ‘rigid’ outer mucus cover is developed as protection against mechanical hazards. Some of the free sugars (α-d-mannose, N-acetylglucosamine, N-acetylgalactosamine β-d-galactose, α-l-fucose) are known to prevent the adherence of different bacteria and fungi to cellular surfaces. Thus a high concentration of such sugars, may impede massive attacks of micro-inhabitants on mobile sponge cells, pinacocytes, and the exopinacoderm layer. 相似文献
19.
Martine Rowell-Rahier Ludger Witte Adelheid Ehmke Thomas Hartmann Jacques M. Pasteels 《Chemoecology》1991,2(1):41-48
Summary
Oreina cacaliae andO. speciosissima (Coleoptera, Chrysomelidae) sequester in their elytral and pronotal defensive secretions pyrrolizidine alkaloids (PAs) as Noxides (PA N-oxides). The PA N-oxide patterns found in the beetles and their host plants were evaluated qualitatively and quantitatively by capillary gas chromatography/mass spectrometry (GC-MS). Of the three host plantsAdenostyles alliariae (Asteraceae) is the exclusive source for PA N-oxide sequestration in the defensive secretions of the beetles. With the exception of O-acetylseneciphylline the N-oxides of all PAs ofA. alliariae, i.e. senecionine, seneciphylline, spartioidine, integerrimine, platyphylline and neoplatyphylline were identified in the secretion. PA N-oxides typical ofSenecio fuchsii (Asteraceae) were detected in the bodies of the beetles but not in their secretion. No PAs were found in the leaves of the third host plant,Petasites paradoxus (Asteraceae). The results suggest the existence of two distinctive storage compartments for PA N-oxides in the beetle: (1) the defensive secretion, containing specifically PA N-oxides acquired fromA. alliariae; (2) the body of the beetle, sequestering additionally but less selectively PA N-oxides from other sources,e.g. S. fuchsii or monocrotaline N-oxide fed in the laboratory. The concentration of PA N-oxides in the defensive secretion is in the range of 0.1 to 0.3 mol/1, which is more than 2.5 orders of magnitude higher than that found in the body of the beetle. No significant differences exist in the ability of the two species of beetles to sequester PA N-oxides fromA. alliariae, althoughO. speciosissima, but notO. cacaliae, produces autogenous cardenolides. A negative correlation seems to exist between the concentrations of plant-derived PA N-oxides andde novo synthesized cardenolides in the defensive secretion ofO. speciosissima. 相似文献
20.
Eisner T Schroeder FC Snyder N Grant JB Aneshansley DJ Utterback D Meinwald J Eisner M 《Chemoecology》2008,18(2):109-119
Summary. Beetles of the family Lycidae have long been known to be chemically protected. We present evidence that North American species
of the lycid genera Calopteron and Lycus are rejected by thrushes, wolf spiders, and orb-weaving spiders, and that they contain a systemic compound that could account,
at least in part, for this unacceptability. This compound, a novel acetylenic acid that we named lycidic acid, proved actively
deterrent in feeding tests with wolf spiders and coccinellid beetles. Species of Lycuscommonly figure as models of mimetic associations. Among their mimics are species of the cerambycid beetle genus Elytroleptus, remarkable because they prey upon the model lycids. We postulated that by doing so Elytroleptus might incorporate the lycidic acid from their prey for their own defense. However, judging from analytical data, the beetles
practice no such sequestration, explaining why they remain relatively palatable (in tests with wolf spiders) even after having
fed on lycids. Chemical analyses also showed the lycids to contain pyrazines, such as were already known from other Lycidae,
potent odorants that could serve in an aposematic capacity to forestall predatory attacks.
David Utterback: Deceased 相似文献