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1.
Summary. Previous studies indicated the presence of antennally-active compounds in extracts of eggs laid by female cabbage root flies,
Delia radicum, that stimulated oviposition by conspecific females. We confirmed that previously laid D. radicum eggs stimulated oviposition by other D. radicum females, in a dose-dependent manner. Methanol extracts of conspecific eggs stimulated oviposition by females D. radicum, whereas egg extracts of D. antiqua and Psila rosae had no effect. Electrophysiological recordings from the tarsal sensilla of D. radicum females indicated that neurones of the C5 sensillum responded to the egg extracts from both D. radicum and D. antiqua, but not P. rosae. Chemical analysis revealed that the extract of eggs from D. radicum contained the thia-triaza-fluorene compound, 1,2-dihydro-3-thia-4,10,10b-triaza-cyclopenta[.a.]fluorene-1-carboxylic acid
(CIF-1), an oviposition stimulant found previously only in cruciferous plants. Another potentially active component has yet
to be identified. 相似文献
2.
Summary. Summary. Oilseed rape, Brassica napus L. (cv Express),
plants were grown under three different sulphur regimes:
sulphur-free (S0), normal sulphur (Sn, normal field concentration)
and a sulphur-rich (S+, 2 × concentration of Sn). We
performed dual choice oviposition assays with the diamondback
moth, Plutella xylostella, using real plants and,
for the first time with this insect, artificial leaves sprayed
with methanolic leaf-surface extracts. The results mirrored
those of a separate study of preferences for whole plants.
Females laid more eggs on surrogate leaves that were
treated with Sn extracts than on S0 plants, while only a
slight, not significant, difference was observed between
extracts of normal and sulphur-rich plants. This shows
that chemical compounds on the leaf surface mediate the
oviposition preference and that the female insect can
perceive the quality of the host-plants in terms of their
fertilisation status.Since leaf volatiles are known to be oviposition stimulants,
we investigated the effects of leaf-surface extracts on
insect olfactory responses using electroantennograms
(EAGs). In agreement with the behavioural data, we found
that extracts of sulphur-treated plants yielded higher EAG
amplitudes than the S0 extracts. Since the leaf content of the
volatiles isothiocyanates is influenced by sulphur nutrition,
we analysed the extracts for these compounds. Above the
detection threshold of our GC-MS system, no isothiocyanates
were found. Thus, other compounds present in the
surface extracts must be perceived by the antenna.However, the HPLC analysis revealed 11 different
glucosinolates. Progoitrin (2-Hydroxy-3-butenyl) and
gluconapoleiferin (2-Hydroxy-4-pentenyl), which belong to
the hydroxy-alkene class of glucosinolates, were the most
abundant compounds. The total glucosinolate content
sharply increased from S0 to Sn plants, whereas it was slightly
lower in n versus S+ plants. Since it is known that glucosinolates
can stimulate oviposition, it seems likely that the
increased content we observed was influencing the insect
preference in this study too. 相似文献
3.
Summary. Feeding by belowground herbivores may induce systemic changes in shoot defence levels that affect the performance of above
ground herbivores and higher trophic levels. In this paper two wild Brassica species, B. nigra and B. oleracea were experimentally infested with 10 larvae of the cabbage root fly, Delia radicum. Plant dry masses and glucosinolate levels in shoots, main roots, and fine roots were determined at 3, 7, 12 and 14 days
after infestation and compared to those of control plants.
The systemic response in the leaves differed between plant species. In B. nigra shoot glucosinolate levels in D. radicum infested plants steadily increased with time until they were almost twice those of controls 14 days after infestation. B. oleracea plants infested with D. radicum did not show significant changes in shoot glucosinolate levels within 14 days, which may be due to the unexpected poorer
performance of D. radicum on this species.
Both plant species showed a local increase in indole glucosinolates in the main roots, which are the preferred feeding site
of D. radicum larvae. B. oleracea plants however showed a stronger (1.9 – 4.7 times) increase in indole glucosinolate levels than B. nigra (1.5 – 2.6 times). The increase in indole glucosinolates in B. nigra main roots, was counterbalanced by a significant decrease in aromatic glucosinolate levels. These differences in local responses
to D. radicum feeding between the two species may have contributed to the slower growth rates of the larvae on B. oleracea. D. radicum feeding did not result in altered glucosinolate levels in the fine roots in either plant species. The differences in glucosinolate
induction patterns between the summer annual B. nigra and the perennial B. oleracea are discussed in the light of their different life histories. 相似文献
4.
Summary. Delia antiqua (Diptera: Anthomyiidae) females lay eggs between the leaves of onion plants or in the soil around the base of the plants,
then the maggots feed on the onion bulb and roots causing rapid secondary infection by fungi and bacteria. It is well known
that the first sensory modality used by the onion fly is vision, therefore the shape (vertical narrow cylinders) and colour
(yellow) of the plant play a crucial role in the recognition of a potential host plant. In the past it has been shown that
n-dipropyl disulfide (Pr2S2), a typical component of onion volatiles, is an important chemical host plant cue. We extracted host leaf surface to verify
if Pr2S2 is the major chemical oviposition stimulant and to determine if other as yet unknown substances may play a role in host-plant
selection. We confirmed that the females laid more eggs around onion plants with leaves than when only the onion bulb was
present and that the odour of chopped onion stimulates oviposition. Extraction of the surface of onion leaves revealed that
only the apolar fraction contained substances that stimulate egg-laying in D. antiqua. GC-EAD analysis indicated that a minor constituent, Pr2S2, is perceived by the olfactory receptor on the antennae of the onion fly females. This confirmed the importance of Pr2S2 as oviposition stimulant. Contact with the polar fraction did not stimulate egg-laying behaviour in this Delia species. We discuss the oviposition strategy of D. antiqua in comparison with its closely related species, D. radicum, in which the oviposition behaviour is stimulated mainly through contact with the cabbage leaf surface and only partially
by the host volatiles. 相似文献
5.
Plant volatiles affect oviposition by codling moths 总被引:4,自引:0,他引:4
Peter Witzgall Lena Ansebo Zhihua Yang Gino Angeli Benoit Sauphanor Marie Bengtsson 《Chemoecology》2005,15(2):77-83
Summary. Oviposition in wild codling moth females, collected as overwintering larvae from apple, pear and walnut, was stimulated by volatiles from fruit-bearing green branches of these respective hostplants. Analysis of headspace collections showed that eight compounds present in apple, pear and walnut elicited a reliable antennal response in codling moth females: (E)--ocimene, 4,8-dimethyl-1,(E)3,7-nonatriene, (Z)3-hexenyl acetate, nonanal, -caryophyllene, germacrene D, (E,E)--farnesene, and methyl salicylate. Any one of these compounds is found in many other non-host plants, and host recognition in codling moth is thus likely encoded by a blend of volatiles. A large variation in the blend proportion of these compounds released from apple, pear and walnut suggests a considerable plasticity in the female response to host plant odours. Wild females, collected as overwintering larvae in the field, laid significantly fewer eggs in the absence of host plant volatiles. The offspring of these females, however, reared on a semi-artificial diet in the laboratory, laid as many eggs with or without plant volatile stimulus. Tests with individual females showed that this rapid change in oviposition behaviour may be explained by selection for females which oviposit in the absence of odour stimuli, rather than by preimaginal conditioning of insects when rearing them on semi-artificial diet. Oviposition bioassays using laboratory-reared females are therefore not suitable to identify the volatile compounds which stimulate egglaying in wild females. 相似文献
6.
Alison M. Barker Reitumetse Molotsane Caroline Müller Urs Schaffner Erich Städler 《Chemoecology》2006,16(4):209-218
Summary. The turnip sawfly Athalia rosae sequesters glucosinolates from its cruciferous host plants in the larval stage. Investigation of the chemosensory and behavioural
responses of adult A. rosae to glucosinolates and their volatile hydrolysis products, isothiocyanates, revealed that females detect glucosinolates by
contact chemoreception and isothiocyanates by antennal olfaction. In electroantennogram recordings, four isothiocyanates (allyl
[2-propenyl] isothiocyanate, benzyl isothiocyanate, butyl isothiocyanate and iberverin [3-methylthiopropyl isothiocyanate])
were active at all doses presented, including the lowest (0.1 μg), whilst the threshold for detection of three others, iberin
[3-methylsulphinylpropyl isothiocyanate], methyl isothiocyanate, and sulforaphane [4-methylsulphinylbutyl isothiocyanate],
was higher, at between 1 and 10 μg (source concentration of volatiles). Allyl isothiocyanate attracted experienced females
in a four-chambered olfactometer, whilst na?ve females showed no response. Allyl isothiocyanate also attracted mature females
to baited yellow water traps in field trials, although immature females were repelled at high isothiocyanate concentrations.
In laboratory behavioural bioassays the glucosinolates sinigrin (allyl [2-propenyl] glucosinolate) and sinalbin (p-hydroxybenzyl
glucosinolate), stimulated ovipositor probing in mature female A. rosae to an extent comparable to hot-water extracts of their host plants. These responses show that glucosinolates and isothiocyanates
play an important role in host finding and host recognition in A. rosae. 相似文献
7.
Summary. We tested the hypothesis that Daphne gnidium is an ancestral host plant of Lobesia botrana. To this end, we studied the oviposition response of this moth to various aerial organs of this plant. Our results show that
females prefer to lay eggs on daphne berries rather than on grapes (cv. chasselas) and that polar surface extracts of daphne
berries and leaves strongly stimulate oviposition in a dosedependant way, whereas flower extracts are weakly stimulant and
branch extracts are inactive or deterrent for oviposition. Furthermore, a total extract of daphne berries stimulates oviposition
in semi-natural conditions when applied onto fresh grapes. Oviposition stimulants from berries were isolated by HPLC coupled
with a dual-choice oviposition bioassay. The ecological value of D. gnidium for L. botrana is discussed and the possible use of oviposition stimulants from daphne, contrasting with the oviposition signal of the cultivated
host plant, is proposed in the perspective of developing behavioural manipulation methods such as stimulo-deterrent diversionary
strategies compatible with IPM programs. 相似文献
8.
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
9.
Olivier Roux Charles Gers Josèphe Nathan Tene-Ghomsi Laurence Arvanitakis Dominique Bordat Luc Legal 《Chemoecology》2007,17(1):13-18
Summary. Cotesia plutellae is a specialist parasitoid of Plutella xylostella. This specificity is potentially under the control of several factors before and after oviposition. Thereby, the stimuli
that lead female parasitoids to host locations and to oviposition, might be at the basis of the specificity. We explore here
the response of C. plutellae females exposed to host cuticular lipids. A total cuticular lipid extract of host caterpillars was fractionated into a hydrocarbon
fraction and a non-hydrocarbon fraction. Neither fraction alone had any effect on oviposition behaviour in C. plutellae but the hydrocarbon fraction alone did seem to have a positive effect on the rate of antennal contact by the females. To
induce oviposition behaviour, both fractions were necessary and reflect cooperation between at least one compound in each
fraction. Identification of cuticular lipids shows that hydrocarbons were dominant (77%). Non-hydrocarbon compounds were mainly
represented by 15-nonacosanone (18% of the total lipid extract). This ketone is rare in insect cuticle lipids and is thought
to originate from the cabbage epicuticle where it is dominant with n-C29 and 14- and 15-nonacosanol also found among the cuticular lipids of the host caterpillar. 相似文献
10.
Summary. Polyphagous caterpillars of the giant geometer
Biston robustum resemble the twigs of their respective food
sources in color and shape. Common predatory ants, including
Lasius and
Formica, were often observed to freely prowl directly on caterpillars bodies, even after antennal contact.
This suggests that the cuticular chemicals of the caterpillars
resemble those of the twigs of the foodplants, so we analyzed
both by GC and GC-MS. The chemical compositions
differed among caterpillars fed on a cherry, Prunus yedoensis,
a chinquapin Castanopsis cuspidata, and a camellia Camellia japonica. The cuticular chemicals of the caterpillars
resembled those of their corresponding food sources.
When the caterpillar diets were switched from the cherry to
camellia or chinquapin at the 4th instars, the caterpillars
cuticular chemicals changed after molting to resemble those
of their respective foods. Caterpillars also changed their
cuticular chemicals when they perched on cherry twigs and
fed on camellia or chinquapin leaves, but not when they
perched on camellia or chinquapin twigs and fed on cherry
leaves. The chemical similarities between the caterpillars
and the twigs were due to the digestion of host leaves, which
indicates that this is a diet-induced adaptation. 相似文献
11.
Leaf surface compound fromBrassica oleracea (Cruciferae) induces oviposition byPieris brassicae (Lepidoptera: Pieridae) 总被引:4,自引:0,他引:4
Joop J. A. van Loon Anton Blaakmeer Frans C. Griepink Teris A. van Beek Louis M. Schoonhoven Aede de Groot 《Chemoecology》1992,3(1):39-44
Summary Chemicals present on the surface of cabbage (Brassica oleracea L.) leaves were extracted by dipping these leaves for 3 s in dichloromethane followed by a 3 s dip in methanol. When offered in dual choice bioassays using green paper cards as a substrate, the methanol extract stimulated oviposition activity byPieris brassicae L. (Lepidoptera: Pieridae) females. The oviposition stimulant was isolated using medium pressure liquid chromatography, reversed-phase HPLC, ion-pair HPLC and ion exchange chromatography. Using1H-NMR spectroscopy, the stimulant could be identified as glucobrassicin (3-indolyl-methyl-glucosinolate). When pure glucobrassicin was offered at a dose identical to that in the crude methanol extract, butterflies did not discriminate between these two substrates in a dual choice test. It is argued that a high sensitivity for indole glucosinolates as host recognition factors may confer an adaptive value for these specialist crucifer feeders. The nutritional significance of their precursor tryptophan and the non-volatile nature of the aglycones formed upon enzymic hydrolysis in damaged tissues are proposed as properties of indole glucosinolates that contribute to this possible adaptive advantage. 相似文献
12.
Jean-Claude Grégoire Daniel Couillien Ralph Krebber Winfried A. König Holger Meyer Wittko Francke 《Chemoecology》1992,3(1):14-18
Summary The predator,Rhizophagus grandis, is linked to its specific prey,Dendroctonus micans, by semiochemical signals regulating oviposition and long range orientation. A mixture of simple oxygenated monoterpenes [(–)—fenchone, (–)—pinocamphone, rac. camphor, terpinene-4-ol, borneol, fenchol and verbenone], identified from the frass ofD. micans has been found to be extremely active in a flight windtunnel as a long—range attractant for the predator. The mixture elicited 84 % of the response to larval frass of the prey. Excluding pinocamphone from the mixture did not influence its activity. Also, changing the absolute configurations of some of the components (fenchol, terpinene-4-ol and borneol) did not influence the predators' response. However, the addition of (–)—-terpineol increased the attractivity of the synthetic blend to almost that of larval frass of the prey. Ecological implications of the identified semiochemicals and their use in pest management are discussed. 相似文献
13.
Summary. Increased abundance of several aliphatic benzyl
and phenylethyl alkanoates were previously associated with
reduced defoliation of
Eucalyptus globulus Labill. by the
autumn gum moth (Mnesampela privata Guenée) in two
clonally replicated F2 families. We examine the robustness
of this association by comparing the abundance of the
implicated foliar wax compounds with defoliation levels in
three plantation sites and a genetics trial in northern
Tasmania. At all locations, the aliphatic alkanoate, benzyl
n-tetracosanoate (C24), was found in significantly higher
abundance in the foliar wax of E. globulus trees that had displayed low M. privata damage (designated resistant) compared to trees that had displayed high damage (designated
susceptible). Further, when sites were combined, benzyl
n-tetracosanoate (C24) accounted for 16 % of variation in
field defoliation. Field defoliation was also positively correlated
to M. privata oviposition both in the field and on
foliage sprigs in a cage. In the cage bioassay, oviposition
accounted for 20 % of variation in field defoliation
making it a better predictor of tree defoliation in the field
than either field oviposition, which accounted for 9 % of
variation, or screening foliage for the abundance of benzyl
n-tetracosanoate (C24). Despite both benzyl n-tetracosanoate
(C24) and oviposition being related to field defoliation, there
was no statistically significant relationship between the
abundance of benzyl n-tetracosanoate (C24) and oviposition
in the field or cage bioassay. Further work is therefore
required to determine if increased levels of this compound in
the foliar wax operates as a direct deterrent to M. privataoviposition. 相似文献
14.
Summary. The purpose of this study was to identify plant volatiles that provide host location cues for adult females of the gall wasp Antistrophus rufus Gillette (Hymenoptera: Cynipidae). Larvae of this species inhabit flowering stems of the prairie perennial Silphium laciniatum L. (Asteraceae). Adult females responded to volatile compounds emitted by stems of S. laciniatum in field olfactometer bioassays. Plant volatiles were monoterpenes, including, in descending order of abundance, racemic - and -pinene (~50% + enantiomer for both), (+)-limonene, (–)-camphene, and -myrcene. In laboratory bioassays, females responded to aeration extracts of plant stems, the full blend of synthetic monoterpenes, and the four-component blend of -pinene, -pinene, (+)-limonene, and (–)-camphene. This monoterpene blend apparently serves as an olfactory cue for host plant location for female A. rufus and is the first such cue to be reported for a cynipid gall wasp. Species-specific ratios of plant monoterpenes may provide cues for gall wasp females to distinguish between plant species and choose appropriate hosts for oviposition. The olfactometer and bioassay techniques developed for this research may be useful for field bioassays of other types of minute arthropods. 相似文献
15.
Summary. Larvae of the turnip sawfly, Athalia rosae L. (Hymenoptera: Tenthredinidae), sequester glucosinolates of their host plants, namely members of the Brassicaceae family,
in their haemolymph. Therefore, they need to circumvent myrosinase activities of the plant tissue which normally hydrolyse
the glucosinolates after plant damage. Effects of varying levels of glucosinolates and myrosinases on the performance of A. rosae were investigated using homozygous lines of Brassica juncea (L.) with either (1) low glucosinolate (lowGS) and low myrosinase (lowMR), (2) high glucosinolate (highGS) and high myrosinase (highMR), or (3) high glucosinolate (highGS) and low myrosinase (lowMR) levels. To insure that the given quantities remained as constant as possible, newly hatched larvae were enclosed on the
second-youngest leaf of a plant, and were offered a new plant of comparable physiological age (6-leaf-stage) every day. The
performance of A. rosae was little affected by leaf quality. Body masses of eonymphs and adults were on average lowest on the highGS/highMR-line, but these differences were rarely significant. The pupal developmental times of females and males were longest on
the highGS/lowMR-line in only one of two replicate experiments. All other performance traits (developmental times of larvae, egg numbers,
adult longevity) were not significantly different. Glucosinolates, sequestered by the larvae, are carried through the pupal
stage. The glucosinolate concentration measured in adult insects reflected the level of the host plant line, without showing
any obvious costs for sequestration. Obviously, A. rosae is highly tolerant to variation in the glucosinolate-myrosinase system of its host.
In addition, induced changes of glucosinolate concentrations and myrosinase activities caused by 24 h-feeding of groups of
three small larvae were analysed in the second-youngest leaves. In contrast to the patterns most herbivores evoke on Brassicaceae,
namely an increase of both glucosinolate concentration and myrosinase activity, we detected a significant decrease of both
traits in all three lines where the respective trait was originally high in the plants. Although glucosinolate levels dropped in the highGS lines about 50%, these still contained higher concentrations than the lowGS line. Whereas the activity of soluble myrosinases remained highest in the highMR line, even after a decrease to almost 30% due to feeding, the levels of insoluble myrosinases converged after feeding in
lowMR and highMR lines. Levels of the signalling molecule salicylic acid slightly decreased on average after feeding, whereas jasmonic acid
was below the detection threshold in almost all samples. The concentration of several molecules varies strongly in plant tissue
with age and can change due to induction by herbivore feeding. Therefore, if performance of an insect species is measured
on plants with specific traits, the variability in these traits needs to be carefully controlled in experiments. 相似文献
16.
Foraging by the herbivorous parrotfish Sparisoma radians 总被引:2,自引:0,他引:2
The foraging behavior of the bucktooth parrotfish Sparisoma radians was studied in seagrass beds off St. Croix, US Virgin Islands and in laboratory preference tests. Thalassia testudinum was the dominant item in the field diet with the epiphytized distal portion of the blades most favored. Other seagrasses, Syringodium filiforme and Halodule wrightii, were taken in relation to their abundance. Several algae were also eaten, particularly Halimeda spp. and Penicillus spp. Although abundances of the algae varied, the fish maintained a steady mixture of plant species in their diet. Laboratory feeding tests for various plants presented in pairs showed clear preferences in nearly all cases. The preference hierarchy was (1) T. testudinum with epiphytes, (2) H. wrightii, (3) T. testudinum without epiphytes, (4) S. filiforme, and the algae, (5) Dictyota divaricata, (6) Enteromorpha flexuosa, (7) Caulerpa mexicana, (8) Halimeda incrassata and (9) Penicillis pyriformis. Preference did not vary significantly with satiation. The catch per unit effort (kilocalories absorbed per bite) was calculated for each plant, using (a) absorption values calculated for S. radians fed the different plants, (b) the calorific values for tested plants, and (c) an estimate of the amount of material taken per bite. The ranking of catch per unit effort closely paralleled the preference hierarchy with the exception of C. mexicana which has a toxin. Fish fed diets of single plants, mixed plant diet, and starved controls showed differential survival which paralleled the preference hierarchy, the most preferred plants leading to longest survival. Comparison of laboratory results with field feeding behavior shows that inclusion of plants in the diet is not related directly to preference rank, availability or survival value, but that the fish deliberately eat a variety of plants presumably which maintains balanced diet. This result indicates that models of optimal foraging for herbivores should include nutrient constraints and avoidance of toxins in order to predict accurately the behavior of an animal in the field. 相似文献
17.
Summary. The oviposition-stimulating activity of (E)-capsaicin identified in the fruits of red pepper, Capsicum annuum L. (Solanaceae), towards the oriental tobacco budworm, Helicoverpa assulta (Guenée), was examined in the laboratory by using choice and no-choice bioassays. Results were compared with those of the
commercially available capsanthin and dihydrocapsaicin, another known constituents of C. annuum fruit, and (Z)-capsaicin. In no-choice oviposition bioassays at 10.5 μg/cm2, (E)-capsaicin was the most active oviposition stimulant. Weak stimulatory activity was observed with capsanthin, (Z)-capsaicin
and dihydrocapsaicin. In choice oviposition bioassays at 2.6 μg/cm2, there were significant differences in oviposition-stimulating activity between (E)-capsaicin and each of the other three alkaloids. Structure-activity relationships indicate that the presence of double bond
and its trans configuration appeared to play a crucial role in the oviposition-stimulating activity. On the basis of our results, (E)-capsaicin acts as a contact oviposition stimulant of female H. assulta. 相似文献
18.
Summary. Leaf disc choice and oviposition bioassays were used to examine the effects of larval experience with a Hoodia gordonii latex on subsequent behaviors. The latex deterred feeding and oviposition by “naïve” cabbage looper (Trichoplusia ni, Noctuidae) larvae and moths with no previous exposure to the material. “Experienced” insects, reared on a diet with the H. gordonii latex (1000 ppm), exhibited lesser feeding deterrence relative to naïve insects. Experienced female moths actually preferred to lay eggs on treated rather than control leaves. There was no observed transfer of behavioral preferences from experienced parents to their offspring. Our results suggest that moths may be acquiring oviposition preferences from larval feeding experience as described by Hopkins’ host selection principal (HHSP) or through chemical legacy. 相似文献
19.
To examine whether the interaction between bumblebees, Bombus ignitus, reduces their foraging area, we conducted bee-removal experiments in a net cage. In the cage, we set potted Salvia farinacea plants, allowed bumblebees to forage freely on those plants, and followed their plant-to-plant movements to identify a bee with a relatively small foraging area. We then removed all the other foraging bees, except for the bee with a small foraging area, and observed the change of the foraging area of the focal bee under conditions of no interaction with other bees. After the removal of the other bees, all five bees tested enlarged their foraging areas, suggesting that the interaction between bees is an important determinant of their foraging areas. The result also means that bumblebees are able to adjust their foraging areas in response to other foragers, indicating the necessity for future studies to clarify what cues bees use to interact with other bees. Moreover, after the removal treatments, all five bees showed temporary increases in the number of flower probes per plant. This can be explained by their optimal foraging according to the old average intake rate for the plant population and by the delayed changes in response to the new high average energy intake rate after the bee-removal treatments.Communicated by M. Giurfa 相似文献
20.
Summary
Acanthoscelides obtectus (Say) is one of the most damaging pests of kidney beans,Phaseolus vulgaris L. worldwide. However, aromatic plants from the families Lamiaceae, Lauraceae, Myrtaceae and Poaceae can protect kidney beans by direct or delayed insecticidal effect, through increased adult mortality and inhibition of beetle reproduction (both oviposition and adult emergence). The efficiency of hydrodistillated and intact plants fromThymus vulgaris andT. serpyllum, Mentha piperata, Rosmarinus officinalis, Satureia hortensis, Eucalyptus globulus, Laurus nobilis, Origanum vulgare, andCymbopogon nardus was compared. For both extracts,Origanum vulgare had the best effect. The insecticidal effect was induced by more than the essential oils because no significant difference was noticed between distilled and intact plants extract. Inhibition of reproduction was particularly important. These results suggest that lipidic as well as non lipidic, allelochemicals, such as phenolics, or non-protein amino-acids, or flavonoids may be involved in the toxicity of aromatic plants to this beetle. 相似文献