共查询到20条相似文献,搜索用时 109 毫秒
1.
Willem J. Boot Minus van Baalen Maurice W. Sabelis 《Behavioral ecology and sociobiology》1995,36(4):283-289
Varroa jacobsoni reproduces both in drone and worker brood cells of honey bees, but in drone cells reproductive success is higher than in worker cells. A simple model using clonal population growth as a fitness measure has been developed to study the circumstances under which specialization on drone brood would be a better strategy than reproduction in both types of cell. For European Apis mellifera, the model suggests that if mites have to wait less than 7 days on average before they can invade a drone cell, specialization on drone brood would be a better strategy. This is close to the estimated waiting time of 6 days. Hence, small differences in reproductive success in drone and worker cells and in the rate of mortality may determine whether specialization on drone brood will be promoted or not. In European A. mellifera colonies, Varroa mites invade both drone and worker cells, but specialization on drone brood cells seems to occur to some extent because drone cells are more frequently invaded than worker cells. In the parasite-host association of V. jacobsoni with African or Africanized A. mellifera or with A. cerana, the mites also invade both drone and worker cells, but the mites specialize on drone brood for reproduction since a large percentage of the mites in worker brood do not reproduce. Only in the parasite-host association of Euvarroa sinhai, a mite closely resembling V. jacobsoni, and A. forea is specialization complete, because these mites only invade drone brood. 相似文献
2.
Mating in the mite Varroa destructor, an ectoparasite of the honeybee, takes place within the sealed brood cell of its host and is triggered by a female sex pheromone consisting of three fatty acids and their respective ethyl esters. In a laboratory bioassay, we observed interactions among offspring of a Varroa female at 11 days after host cell capping in the absence and in the presence of the sex pheromone and clearly demonstrated that male mites were not able to distinguish between receptive daughters and either older or immature and unreceptive females when exposed to the pheromone. In addition, mating attempts in the presence of the pheromone with otherwise receptive females were clearly of shorter duration and males often failed to select a receptive female. In order to evaluate the effect of pheromone exposure on successful copulations and the number of spermatozoa transferred under field conditions, we sprayed one of the pheromone components, oleic acid, on an empty brood comb before host egg-laying and Varroa infestation and counted the spermatozoa of daughter mites taken from this comb. We could show that the number of spermatozoa was indeed reduced, and 20 % of females lacked spermatozoa. Our results open up new possibilities and represent a promising step toward biological control of Varroa mites in beehives. 相似文献
3.
The impact of a parasitic infestation may be influenced by nutritional state, in both individuals and colonies. This study
examined the interaction between pollen storage and the effects of an infestation by the mite, Varroa jacobsoni Oudemans, in colonies of the honey bee, Apis mellifera L. We manipulated the pollen storage and mite infestation levels of colonies, and measured pollen foraging and brood rearing.
Increased pollen stores decreased both the number of pollen foragers and pollen load size, while initially at least foragers
from colonies with moderate infestations carried smaller pollen loads than those from lightly infested colonies. Over the
course of the experiment, all colonies significantly increased pollen-foraging rates and pollen consumption, which was presumably
a seasonal effect. Lightly infested colonies exhibited a larger increase in pollen forager number than moderately infested
colonies, suggesting that more intense mite infestations compromised forager recruitment. Brood production was not affected
by the addition of pollen, but moderately infested colonies were rearing significantly less brood by the end of the experiment
than lightly infested colonies. Furthermore, the efficiency with which colonies converted pollen to brood decreased as the
pollen storage level decreased and the infestation level increased. The results of this study may indicate that honey bee
colonies adaptively alter brood-production efficiency in response to parasitic infestations and seasonal changes.
Received: 3 May 1999 / Received in revised form: 14 September 1999 / Accepted: 25 September 1999 相似文献
4.
Letizia Mattiacci Sara Rudelli Bettina Ambühl Rocca Sem Genini Silvia Dorn 《Chemoecology》2001,11(4):167-173
Summary. Plant responses to herbivory might directly affect the herbivore (“direct” defences) or might benefit the plant by promoting
the effectiveness of natural antagonists of the herbivores (“indirect” defences). Brussels sprouts attacked by Pieris brassicae larvae release volatiles that attract a natural antagonist of the herbivores, the parasitoid Cotesia glomerata, to the damaged plant. In a previous study, we observed that feeding by caterpillars on the lower leaves of the plant triggers
the systemic release of volatiles detectable by the parasitoids from upper leaves of the same plant.?The role of these systemically
induced volatiles as indirect defence and the dynamics of their emission were investigated in wind-tunnel dual choice tests
with C. glomerata. The systemically induced emission of volatiles varied depending on leaf age and on plant age. Systemic induction affected
parasitoid effectiveness, as induced plants could be more easily located by parasitoids than non-induced ones.?The role of
the systemic induction as a direct defence was investigated through behavioural and feeding tests with P. brassicae. In dual choice assays, 1st instar larvae preferred to feed and fed more on systemically induced than on non-induced leaves.
In single choice assays, the leaf area consumed by caterpillars was larger on systemically induced leaves than on non-induced
control leaves. However, caterpillars fed on systemically induced leaves attained the same weight as those feeding on non-induced
controls. In addition, P. brassicae pupae whose larvae were fed on systemically induced leaves had longer developmental times than those of larvae fed on non-induced
leaves. Adult oviposition behavior was not influenced by systemic induction.?We conclude that systemically induced responses
in cabbage might reduce P. brassicae fitness both directly, by affecting their development and feeding behavior and indirectly by making caterpillars and pupae
more vulnerable to attack by carnivores. The occurrence of a possible relationship between direct and indirect defence is
discussed.
Received 24 January 2001; accepted 3 May 2001. 相似文献
5.
Alkaloid tolerance in Manduca sexta and phylogenetically related sphingids (Lepidoptera: Sphingidae) 总被引:2,自引:0,他引:2
Summary. Nicotine tolerance is well known for Manduca sexta. It also occurs in several other sphingids of the subfamilies Macroglossinae and Sphinginae. Only members of the subfamily
Smerinthinae appear to be more susceptible to nicotine intoxication. Phylogenetic trees have been reconstructed from mitochondrial
16S rDNA and nuclear DNA to map nicotine tolerance.?The nicotine binding site of both α-subunits of nicotinic acetylcholine receptors (nAChR) have been amplified and sequenced. No apparent amino acid substitution
can be seen in the putative nicotine binding site of the α-subunits of nAChR from nicotine tolerant and nicotine sensitive sphingids. Thus, a simple target-site modification can be
ruled out as a cause for nicotine tolerance. This finding agrees with feeding experiments: larvae of M. sexta and other sphingids of the Macroglossinae and Sphinginae not only tolerated nicotine, but also many other alkaloids that
affect neuroreceptors other than acetylcholine receptors (nAChR, mAChR).?Only 10 to 20% of nicotine injected into larvae of
nicotine-tolerant taxa could be recovered later as free nicotine, nicotine N-oxide or cotinine, i.e., 80 to 90% must have been converted to polar conjugates or degradation products which are not detectable with the methods
applied. Usually more than 98% of the recoverable alkaloids were found in the faeces. Excretion reached a maximum 6 h after
injection in tolerant taxa. Larvae of Manduca sexta, which were reared on a nicotine-rich diet, showed higher nicotine degradation and faster nicotine elimination than na?ve
larvae. Application of the cytochrome P450 inhibitor SKF 525A (proadifen) reduced the formation of nicotine N-oxide and the rate of alkaloid degradation. Thus, an
inducible detoxification mechanism, coupled with a rapid and inducible excretion, appear to be a strategy in Sphingidae that
helps them to live on host plants rich in otherwise toxic secondary metabolites.
Received 23 March 2001; accepted 4 August 2001. 相似文献
6.
Summary. Sequestration of plant toxins in herbivores is often
correlated with aposematic coloration and gregarious behaviour. Larvae
of Pieris brassicae show these conspicuous morphological and behavioural
characteristics and were thus suggested to sequester glucosinolates that
are characteristic secondary metabolites of their host plants. P. rapaeare camouflaged and solitary, and are thus not expected to sequester. To
test this hypothesis and to check the repeatabi-lity of a study that did
report the presence of the glucosinolate sinigrin in P. brassicae,
larvae were reared on three species of Brassicaceae (Sinapis alba,
Brassica nigra and Barbarea stricta), and different leaf and insect
samples were taken for glucosinolate analysis. The major host plant
glucosinolates could only be found in traces or not at all in larval
haemolymph, bled or starved larvae, faeces or pupae of both species or
P. brassicae regurgitant. Haemolymph of both Pieris spp. was not
rejected by the ant Myrmica rubra in dual-choice assays; the regurgitant
of P. brassicae was rejected. This suggests the presence of compounds
other than glucosinolates that might be sequestered in or produced by P.
brassicae only. In faeces of both Pieris spp. a compound which yielded
4-hydroxybenzylcyanide (HBC) upon incubation with sulfatase was detected
in high concentrations when larvae had been reared on S. alba. This
compound may be derived from hydrolysis of sinalbin, the main
glucosinolate of that plant. The unidentified HBC progenitor was
apparently not sequestered in the two Pieris spp., and was not detected
in faeces of larvae reared on B. nigra or B. stricta.
Received 18 July 2002; accepted 11 September 2002. 相似文献
7.
Tanya Pankiw Robert E. Page Jr M. Kim Fondrk 《Behavioral ecology and sociobiology》1998,44(3):193-198
Foraging and the mechanisms that regulate the quantity of food collected are important evolutionary and ecological attributes
for all organisms. The decision to collect pollen by honey bee foragers depends on the number of larvae (brood), amount of
stored pollen in the colony, as well as forager genotype and available resources in the environment. Here we describe how
brood pheromone (whole hexane extracts of larvae) influenced honey bee pollen foraging and test the predictions of two foraging-regulation
hypotheses: the indirect or brood-food mechanism and the direct mechanism of pollen-foraging regulation. Hexane extracts of
larvae containing brood pheromone stimulated pollen foraging. Colonies were provided with extracts of 1000 larvae (brood pheromone),
1000 larvae (brood), or no brood or pheromone. Colonies with brood pheromone and brood had similar numbers of pollen foragers,
while those colonies without brood or pheromone had significantly fewer pollen foragers. The number of pollen foragers increased
more than 2.5-fold when colonies were provided with extracts of 2000 larvae as a supplement to the 1000 larvae they already
had. Within 1 h of presenting colonies with brood pheromone, pollen foragers responded to the stimulus. The results from this
study demonstrate some important aspects of pollen foraging in honey bee colonies: (1) pollen foragers appear to be directly
affected by brood pheromone, (2) pollen foraging can be stimulated with brood pheromone in colonies provided with pollen but
no larvae, and (3) pollen forager numbers increase with brood pheromone as a supplement to brood without increasing the number
of larvae in the colony. These results support the direct-stimulus hypothesis for pollen foraging and do not support the indirect-inhibitor,
brood-food hypothesis for pollen-foraging regulation.
Received: 5 March 1998 / Accepted after revision: 29 August 1998 相似文献
8.
Summary. Varroa reproduction is closely synchronized to the development of its host. In this study we present a
new bioassay for field and laboratory tests to evaluate host
factors triggering Varroa oogenesis. Female mites deprived of feeding activated oogenesis when perceiving larval
volatiles. In laboratory assays the living L5-larva and pentane
extracts of the larval cuticle had a clear activating
effect. Wax and larval food did not elicit Varroa oogenesis. The activating components apparently are in the polar fraction
of the cuticular volatiles. The consequences of this
regulative mechanism for the host parasite relationship and
prospects for further research are discussed. 相似文献
9.
Karen M. Kester Steven C. Peterson Frank Hanson D. Michael Jackson R. F. Severson 《Chemoecology》2002,12(1):1-10
Summary. Field observations indicated that hornworms select feeding sites non-randomly on tobacco. We tested the hypotheses that differences
in feeding site locations of larvae of Manduca
sexta L. and Manduca
quinquemaculata (Haworth) (Lepidoptera: Sphingidae) on tobacco could be explained by differential nicotine concentrations within plants and
leaves, species-specific responses to nicotine, or pressure exerted by natural enemies. Results showed that third-instar larvae
of M. sexta fed more proximally and centrally on the leaf, whereas M. quinquemaculata fed more distally. Within-plant selection of leaves did not differ; both species selected leaves in the middle region of
the plant. Nicotine concentrations in a high nicotine genotype, NC95, varied within each leaf, increasing 2—3 fold from the
basal to apical portion of the leaf, and within each plant, increasing 7—10 fold from the first fully expanded leaf to the
twelfth (lowest) leaf. In laboratory bioassays, both Manduca species responded to nicotine as a feeding deterrent. Electrophysiological studies demonstrated that gustatory organs of
both species responded to nicotine at concentrations found in tobacco leaves and that M. quinquemaculata generally showed a less vigorous response to nicotine than M. sexta. Field mortality of M. sexta due to parasitism by Cotesia
congregata (Say) and to parasitism and predation combined differed among feeding sites; predation alone did not. Results suggest that
although nicotine concentration and species specific responses to nicotine play a role in determining feeding site locations,
pressure exerted by natural enemies, especially parasitism by C. congregata, is more important.
Received 22 February 2000; accepted 20 July 2001. 相似文献
10.
The evolution of polyandry by queens in social Hymenoptera: the significance of the timing of removal of diploid males 总被引:1,自引:0,他引:1
Francis L. W. Ratnieks 《Behavioral ecology and sociobiology》1990,26(5):343-348
Summary Multiple mating by queens in social Hymenoptera with single locus sex determination may be an adaptation to reduce the effect of genetic load caused by the production of diploid males, if there is a concave relationship between queen fitness and the proportion of diploid male offspring in the colony. In this situation queens should be selected to reduce the variance in the production of diploid male offspring by multiple mating. It has been suggested that this concave relationship occurs in species such as the honey bee, Apis mellifera, in which reproduction occurs near the peak of colony population. This paper suggests that the timing of diploid male removal may influence mating frequency, with early removal of diploid males favoring multiple mating and late removal of diploid males favoring single mating. This idea is explored in two ways. A mathematical model shows that cell use in the brood area of species that rear young in cells will be more efficient with multiple mating. This would favor multiple mating in species, such as the honey bee, in which brood rearing is constrained by the usable area of the brood chamber. Secondly, comparison of polyandrous honey bees (early removal of diploid males as young larvae) with monandrous fire ants, Solenopsis invicta, and Melipona bees (non-removal of immature diploid males) suggests that in the species without diploid male removal, variance reduction may reduce queen fitness. Suggestions are made for testing this hypothesis. 相似文献
11.
12.
Summary. A widely distributed host race of Tyria jacobaeae lives on Senecio jacobaea and related species and accumulates pyrrolizidine alkaloids (“PA race”), another race, which is restricted to the Alps and
found on Petasites paradoxus, sequesters sesquiterpenes, such as petasol and isopetasol. Nucleotide sequences of the mitochondrial 16S rDNA gene show
1% sequence divergence, indicating that genetical differences exist between the PA exploiting and the terpene-sequestering
host races of T. jacobaeae. This finding suggests that both host races of T. jacobaeae must have been separated for some time already, possibly since the Pleistocene.
Received 2 May 2001; accepted 1 June 2001. 相似文献
13.
The concept of a suite of foraging behaviors was introduced as a set of traits showing associative directional change as a characterization of adaptive evolution. I report how naturally selected differential sucrose response thresholds directionally affected a suite of honey bee foraging behaviors. Africanized and European honey bees were tested for their proboscis extension response thresholds to ascending sucrose concentrations, reared in common European colonies and, captured returning from their earliest observed foraging flight. Race constrained sucrose response threshold such that Africanized bees had significantly lower sucrose response thresholds. A Cox proportional hazards regression model of honey bee race and sucrose response threshold indicated that Africanized bees were 29% (P<0.01) more at risk to forage over the 30-day experimental period. Sucrose response threshold organized age of first foraging such that each unit decrease in sucrose response threshold increased risk to forage by 14.3% (P<0.0001). Africanized bees were more likely to return as pollen and water foragers than European foragers. Africanized foragers returned with nectar that was significantly less concentrated than European foragers. A comparative analysis of artificial and naturally selected populations with differential sucrose response thresholds and the common suite of directional change in foraging behaviors is discussed. A suite of foraging behaviors changed with a change in sucrose response threshold that appeared as a product of functional ecological adaptation.Communicated by R.F.A. Moritz 相似文献
14.
Foraging behavior and the mechanisms that regulate foraging activity are important components of social organization. Here
we test the hypothesis that brood pheromone modulates the sucrose response threshold of bees. Recently the honeybee proboscis
extension response to sucrose has been identified as a ”window” into a bee’s perception of sugar. The sucrose response threshold
measured in the first week of adult life, prior to foraging age, predicts forage choice. Bees with low response thresholds
are more likely to be pollen foragers and bees with high response thresholds are more likely to forage for nectar. There is
an associated genetic component to sucrose response thresholds and forage choice such that bees selected to hoard high quantities
of pollen have low response thresholds and bees selected to hoard low quantities of pollen have higher response thresholds.
The number of larvae in colonies affects the number of bees foraging for pollen. Hexane-extractable compounds from the surface
of larvae (brood pheromone) significantly increase the number of pollen foragers. We tested the hypothesis that brood pheromone
decreases the sucrose response threshold of bees, to suggest a pheromone- modulated sensory-physiological mechanism for regulating
foraging division of labor. Brood pheromone significantly decreased response thresholds as measured in the proboscis extension
response assay, a response associated with pollen foraging. A synthetic blend of honeybee brood pheromone stimulated and released
pollen foraging in foraging bioassays. Synthetic brood pheromone had dose-dependent effects on the modulation of sucrose response
thresholds. We discuss how brood pheromone may act as a releaser of pollen foraging in older bees and a primer pheromone on
the development of response thresholds and foraging ontogeny of young bees.
Received: 24 May 2000 / Revised: 26 September 2000 / Accepted: 15 October 2000 相似文献
15.
Varroa jacobsoni, an ectoparasite of the Asian honeybeeApis cerana, has been introduced world-wide, and is currently decimating colonies of the European honeybeeApis mellifera.Varroa's reproductive cycle is tuned to that of drone cells, those mainly parasitized in the original host. We describe here how a single fertilized female, infesting a brood cell, can produce two to four adult fertilized females within the limited time span of bee development (270 h in worker and 320 h in drone cells), despite the disturbance caused by cocoon spinning and subsequent morphological changes of the bee. From observations on transparent artificial cells we were able to show how the mite combats these problems with specialized behaviors that avoid destruction by the developing bee, prepares a feeding site for the nymphs on the bee pupa, and constructs a fecal accumulation on the cell wall which serves as a rendezvous site for matings between its offspring. The proximity of the fecal accumulation to the feeding site facilitates feeding by the maturing progeny. However, communal use of the feeding site leads to competition between individuals, and protonymphs are most disadvantaged. This competition is somewhat compensated by the timing of oviposition by the mites. Use of a common rendezvous and feeding site by two or moreVarroa mothers in multiinfested cells may have developed from the parental care afforded to them as nymphs. 相似文献
16.
Summary. The ability to perceive and respond to phytochemicals that reliably indicate poor suitability of a potential host plant confers
a selective advantage to ovipositing female swallowtail butterflies. Papilio glaucus females are generalists that nonetheless do not oviposit on red bay (Persea borbonia: Lauraceae). Red bay is toxic to P. glaucus neonates but is commonly found in habitats alongside their principal host plant, Magnolia virginiana, in central Florida. The hypothesis that deterrent compounds present in the leaves of red bay mediate its rejection by P. glaucus was evaluated in our study. Florida populations of P. glaucus did not oviposit on host leaves sprayed with the methanol extract of red bay foliage, although they accepted solvent-treated
and untreated tulip tree leaves in 3 choice bioassays. Additionally, tulip tree leaves sprayed with methanolic extracts of
red bay also deterred oviposition by P. glaucus females from Ohio, Kentucky and Pennsylvania, although these populations do
not naturally encounter red bay. Clearly, deterrent compounds found within this non-host are the basis of its rejection by
populations of P. glaucus and such recognition is fundamental to the species, not just a reflection of local adaptations.
Received 2 April 1999; accepted 11 June 1999. 相似文献
17.
Summary. Analysis of South-East Asian troidine swallowtails revealed high variability in the content of aristolochic acids among individuals.
The presence or absence of these compounds depends on the Aristolochia species available as food plant for the larvae. Only one plant species (Aristolochia philippinensis) contained a high concentration of aristolochic acids, while other species from various localities contained none or only
marginal amounts. Whether aristolochic acids have a distinct function in chemical defense of these swallowtails is still an
open question.
Received 11 December 2000; accepted 4 August 2001. 相似文献
18.
Effects of hydrolysable tannins on a herbivorous insect: fate of individual tannins in insect digestive tract 总被引:2,自引:0,他引:2
Summary. We investigated the effects of four chemically characterised galloylglucoses (GGs, a subgroup of hydrolysable tannins) and
their hydrolysis product, gallic acid (GA), on consumption and performance of larvae of the autumnal moth Epirrita autumnata. Larvae were fed with birch (Betula pubescens) leaves that had been painted individually with each of the compounds at two levels, 5 and 20 mg/g. In addition, we investigated
the fates of the leaf-painted GGs and GA in the E. autumnata digestive tract by comparing phenolics in leaves consumed and in faeces. In general, GGs reduced leaf consumption by E. autumnata during the second and fourth instars, although there was high compound- and instar-specific variation. However, GGs did not
affect the leaf consumption rates by the most voracious fifth instar larvae. This resulted in approximately the same loss
of total biomass by the experimental tree, regardless of the nature and level of GGs enriched to its foliage. The characteristic
fate of hydrolysable tannins, i.e. hydrolysis, was evidenced in the larval digestive tract for three of the four leaf-painted
GGs. In addition to hydrolysis, the almost total absence of GGs in larval faeces was presumably related to the oxidation of
GGs. The dose-dependent excretion percentage of ingested GA showed that it's faecal content should not be used, although it
commonly is, to calculate the level of GG hydrolysis. Moreover, by comparing the non-uniform appearance of faecal tetragalloylglucoses,
whether ingested as such or hydrolysed from pentagalloylglucose, we concluded that a major part of oxidation of GGs occurs
before their hydrolysis in the digestive tract of E. autumnata. Criticism against the common use of tannic acid, a heterogeneous mixture of GA and GGs, in ecological studies is presented.
Received 15 May 2002; accepted 16 July 2002 相似文献
19.
Toshiharu Akino 《Chemoecology》2002,12(2):83-89
Summary. The myrmecophilous beetles, Zyras comes (Staphylinidae) and Diaritiger fossulatus (Pselaphidae) are guests of the black shining ant Lasius fuliginosus. Host worker ants never attacked these beetles, and often gave regurgitant to Z. comes following tactile communication with the beetle. By contrast, the workers from colonies without the myrmecophiles showed
hostile responses towards Z. comes before tactile contact, but were not aware of D. fossulatus until contact. In L. fuliginosus, workers within a colony shared profiles, but the profiles differed among colonies. GC analyses showed that both Z. comes and D. fossulatus beetles had the same hydrocarbons as L. fuliginosus, and the profiles were more similar to those of the host colony workers than the foreign workers. Both Z. comes and D. fossulatus appear to imitate the hydrocarbon profile of their host workers, allowing integrating into the host nest. A Y-maze bioassay
indicated that Z. comes can follow the trail pheromone of L. fuliginosus. This suggests that Z. comes may detect other chemical signals of L. fuliginosus to keep closer interactions with the workers.
Received 22 June 2001; accepted 12 November 2001. 相似文献
20.
Rupert L. L. Kellner 《Chemoecology》2002,12(3):133-138
Summary. Endosymbiotic bacteria implicated in pederin production of Paederus (+)-females (Coleoptera: Staphylinidae) can be transmitted horizontally within and less frequently among the three species
analyzed (P. melanurus, P. riparius, P. sabaeus). The 16S rDNA isolated from (+)-females reveals closely related bacterial sequences in the three species as well as in Paederus fuscipes and Paederidus ruficollis. This confirms the association of the undescribed endosymbiont and pederin biosynthesis in 5 of the 13 species that have
been shown to contain the substance. In spite of the high sequence identities (> 99.5%), which suggest one species of endosymbiont,
some of the heterospecific hosts were incompatible. This indicates adaptation and specific preferences of the endosymbiont
for their natural host.
Received 5 December 2001; accepted 11 March 2002. 相似文献