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1.
Tan K Radloff SE Li JJ Hepburn HR Yang MX Zhang LJ Neumann P 《Die Naturwissenschaften》2007,94(6):469-472
The vespine wasps, Vespa velutina, specialise in hawking honeybee foragers returning to their nests. We studied their behaviour in China using native Apis cerana and introduced A. mellifera colonies. When the wasps are hawking, A. cerana recruits threefold more guard bees to stave off predation than A. mellifera. The former also utilises wing shimmering as a visual pattern disruption mechanism, which is not shown by A. mellifera. A. cerana foragers halve the time of normal flight needed to dart into the nest entrance, while A. mellifera actually slows down in sashaying flight manoeuvres. V. velutina preferentially hawks A. mellifera foragers when both A. mellifera and A. cerana occur in the same apiary. The pace of wasp-hawking was highest in mid-summer but the frequency of hawking wasps was three
times higher at A. mellifera colonies than at the A. cerana colonies. The wasps were taking A. mellifera foragers at a frequency eightfold greater than A. cerana foragers. The final hawking success rates of the wasps were about three times higher for A. mellifera foragers than for A. cerana. The relative success of native A. cerana over European A. mellifera in thwarting predation by the wasp V. velutina is interpreted as the result of co-evolution between the Asian wasp and honeybee, respectively. 相似文献
2.
Environmental variability is expected to be important in shaping performance curves, reaction norms of phenotypic traits related
to fitness. Models predict that the breadth of performance curves should increase with environmental variability at the expense
of maximal performance. In this study, we compared the thermal performance curves of two sympatric populations of the parasitoid
Venturia canescens that were observed under contrasting thermal regimes in their respective preferred habitats and differing in their modes
of reproduction. Our results confirm the large effect of developmental temperature on phenotypic traits of insects and demonstrate
that thelytokous and arrhenotokous wasps respond differently to temperature during development, in agreement with model predictions.
For traits related to fecundity, thelytokous parasitoids, which usually occur in stable thermal conditions, exhibit specialist
performance curves, maximising their reproductive success under a restricted range of temperature. In contrast, arrhenotokous
parasitoids, which occur in variable climates, exhibit generalist performance curves, in keeping with the hypothesis "jack
of all temperatures, master of none". 相似文献
3.
The queenless ant Pristomyrmex punctatus (Hymenoptera: Myrmicinae) has a unique society that differs from those of other typical ants. This species does not have
a queen, and the workers lay eggs and produce their clones parthenogenetically. However, a colony of these ants does not always
comprise members derived from a single clonal line. In this study, we examined whether P. punctatus changes its “assembling behavior” based on colony genetic structure. We prepared two subcolonies—a larger one comprising
200 individuals and a smaller one comprising 100 individuals; these subcolonies were established from a single stock colony.
We investigated whether these subcolonies assemble into a single nest. The genetically monomorphic subcolonies (single clonal
line) always fused into a single nest; however, the genetically polymorphic subcolonies (multiple clonal lines) did not tend
to form a single colony. The present study is the first to demonstrate that the colony genetic structure significantly affects
social viscosity in social insects. 相似文献
4.
The fungus gardens of fungus-growing ants are a potentially valuable resource for exploitation by natural enemies, but few of these antagonistic interactions have been studied. Here we describe key aspects of the behavioral ecology of Gnamptogenys hartmani (Ponerinae: Ectatommini), a specialized agro-predator of Trachymyrmex and Sericomyrmex fungus-growing ants in Panama. Raiding columns of G. hartmani attack and usurp nests with remarkably little effort: a few intruding workers are sufficient to cause panic among the attine ants and make them abscond from the nest. Both G. hartmani larvae and adults consume the fungus and the host brood, after which the colony migrates to a new fungus-growing ant nest discovered by scouting workers. The morphology of the G. hartmani larval mouthparts is similar to that of Gnamptogenys species with a non-fungal diet. However, we suggest that the presence of long spinules on the larval mandibles in the genus Gnamptogenys, comparable to those found in attine larvae, may have pre-adapted G. hartmani to fungus eating. G. hartmani workers do not actively maintain or modify fungus gardens, which makes them less efficient exploiters than Megalomyrmex, the only other agro-predatory ant species known so far. 相似文献
5.
Initiatives for reducing anthropogenic greenhouse gas emissions from deforestation and degradation require transparent and
robust methodologies for the estimation of emissions reduction or removal. Although carbon (C) stock change in degradation
and devegetation by remote sensing are becoming increasingly powerful, the drivers of degradation, wood collection and harvest
dynamics, cannot be understood without “on the ground” sampling. A methodological tool for the quantitative and qualitative
analysis of forest degradation is proposed as developed based on a research on the stump history in the black locust degrading
stands sampled in southwest Romania. Based on the survey of stumps, the cutting regime and wood extraction is determined over
a past period of some 15 years. Stump age classification comprises multiple qualitative criteria (i.e. bark features; adherence
of sprouts; cut edge features; etc.). The method allows for a quantitative assessment of wood removal over time, and is suitable
for the development of a dynamic baseline and monitoring of degradation avoidance activities. 相似文献
6.
Microplitis croceipes (Hymenoptera: Braconidae) is a larval parasitoid of Helicoverpa/Heliothis spp. In the course of mass rearing of M. croceipes, we found that females oviposited in the conspecific adults in rearing cages. When 20 pairs of inexperienced females and
males or of experienced females and males were reared in a cage, the males lived for 14–15 days and the females for 18–20 days
on average. At their death, 37–42% of the males and 50–57% of the females contained conspecific eggs or first instar larvae
in their abdominal cavity. When two of inexperienced females met on a host-infested leaf of soybean, they attempted to sting
each other. Of the attacked females, 30% contained a conspecific egg laid in their abdomen. In abdominal cavity of the adults
parasitized by a conspecific female, the majority of the parasitoid eggs laid disappeared within 1 day after oviposition.
Only 10–30% of the parasitoid eggs laid in conspecific adults hatched 3–4 days after oviposition, but those larvae never molted
to second instar. When the adults were stung by one or two conspecific females, their subsequent longevity was significantly
shorter than that for the control adults. Oviposition in conspecific adults may be prevalent in other parasitic wasps that
quickly oviposit without intensive host examination, and have cuticle and size of abdomen to be stung by conspeicifcs. 相似文献
7.
The bumblebee Bombus terrestris is not only an effective pollinator, but also a potential invasive alien species outside its native range. Recently, nearly
30% of queens of the Japanese native species Bombus hypocrita sapporoensis and B. hypocrita hypocrita were estimated to copulate with B. terrestris males in the field, suggesting that indigenous bumblebees could be genetically deteriorated through hybrid production with
the introduced species. In this study, we evaluated hybrid production between the introduced B. terrestris and the indigenous B. hypocrita sapporoensis under laboratory conditions. The hatching rate of eggs derived from interspecific matings was 0% and 8.6% depending on the
direction of the cross, which was significantly lower than that from intraspecific matings of B. terrestris (76.9%) and B. hypocrita sapporoensis (78.9%). Genetic studies using microsatellite markers revealed that both haploid and diploid individuals were present in
the egg stage, whereas all hatched larvae were haploid. In addition, histological studies revealed that eggs derived from
interspecific matings terminated development 2 days after oviposition. These results strongly suggested that eggs derived
from interspecific matings are inviable due to post-mating isolation mechanisms. Mass release of exotic pollinators could
cause serious population declines of native bumblebee species. 相似文献
8.
Virgin female cabbage butterflies, Pieris rapae crucivora, accept and mate with courting males, whereas mated females reject them and assume the “mate refusal posture”. This study
tested whether the biogenic amines, serotonin (5HT), dopamine (DA), and octopamine (OA), were responsible for this change
in behavior. The results showed that 2–3-day-old virgin females fed with 5HT rejected courting males significantly more frequently
compared with controls fed on sucrose. In contrast, the proportions of courting males rejected by virgin females fed with
either DA or OA did not differ from sucrose-fed controls. Oral application of each amine resulted in significantly increased
levels of the amine applied (or its metabolite) in the brain. The results strongly suggest that 5HT or a 5HT metabolite may
be responsible for the post-mating change in behavioral response of 2–3-day-old virgin females to courting males. Similar
effects of 5HT treatment were observed in 6–8-day-old virgin females, but in this case the results were only marginally different
from the controls, suggesting that the effect may decline with increasing female age. 相似文献
9.
Genetic variation in honeybee, Apis mellifera, populations can be considerably influenced by breeding and commercial introductions, especially in areas with abundant beekeeping. However, in southern Africa apiculture is based on the capture of wild swarms, and queen rearing is virtually absent. Moreover, the introduction of European subspecies constantly failed in the Cape region. We therefore hypothesize a low human impact on genetic variation in populations of Cape honeybees, Apis mellifera capensis. A novel solution to studying genetic variation in honeybee populations based on thelytokous worker reproduction is applied to test this hypothesis. Environmental effects on metrical morphological characters of the phenotype are separated to obtain a genetic residual component. The genetic residuals are then re-calculated as coefficients of genetic variation. Characters measured included hair length on the abdomen, width and length of wax plate, and three wing angles. The data show for the first time that genetic variation in Cape honeybee populations is independent of beekeeping density and probably reflects naturally occurring processes such as gene flow due to topographic and climatic variation on a microscale. 相似文献
10.
Most of the oxalotrophic bacteria are facultative methylotrophs and play important ecological roles in soil fertility and
cycling of elements. This study gives a detailed picture of the taxonomy and diversity of these bacteria and provides new
information about the taxonomical variability within the genus Methylobacterium. Twelve mesophilic, pink-pigmented, and facultatively methylotrophic oxalate-oxidizing strains were included in this work
that had been previously isolated from the soil and some plant tissues by the potassium oxalate enrichment method. The isolates
were characterized using biochemical tests, cellular lipid profiles, spectral characteristics of carotenoid pigments, G+C
content of the DNA, and 16S rDNA sequencing. The taxonomic similarities among the strains were analyzed using the simple matching
(S
SM) and Jaccard (S
J) coefficients, and the UPGMA clustering algorithm. The phylogenetic position of the strains was inferred by the neighbor-joining
method on the basis of the 16S rDNA sequences. All isolates were Gram-negative, facultatively methylotrophic, oxidase and
catalase positive, and required no growth factors. Based on the results of numerical taxonomy, the strains formed four closely
related clusters sharing ≥85% similarity. Analysis of the 16S rDNA sequences demonstrated that oxalotrophic, pink-pigmented,
and facultatively methylotrophic strains could be identified as members of the genus Methylobacterium. Except for M. variabile and M. aquaticum, all of the Methylobacterium type strains tested had the ability of oxalate utilization. Our results indicate that the capability of oxalate utilization
seems to be an uncommon trait and could be used as a valuable taxonomic criterion for differentiation of Methylobacterium species. 相似文献
11.
The sympatric neotropical termites Nasutitermes corniger and Nasutitermes ephratae are clearly distinguishable based on morphology, nest architecture, defensive secretion composition, and molecular markers.
However, given the extensive ecological, geographical, and behavioral overlap of these closely related species, the potential
for interbreeding may exist. To explore this possibility, heterospecific pairs were formed experimentally to examine courtship
and colony-establishment behaviors, and reproductive potential. Courtship and nest construction behavior occurred in heterospecific
pairs in a similar manner to that of conspecific pairs. Survival of pairs depended upon the species of the female partner.
N. ephratae females paired with N. corniger males produced as many offspring as conspecific pairs. N. corniger females mated to N. ephratae males, however, produced significantly fewer offspring at 60 days post-establishment than the reciprocal cross or conspecific
N. ephratae or N. corniger pairs. This was also the only pairing in which any aggression was observed. Heterospecific pairs and groups formed in mate
choice mesocosms, suggesting that species recognition between these two termites is not an important aspect of mate choice.
Overall, species mismatch tolerance and hybrid offspring viability are high. The present data, together with previous evidence
from defensive secretions and isozyme analysis, suggest that hybridization may periodically occur in nature, and that reproductive
barriers between these two species may be incomplete. Hybridization could provide a rare but important source of genetic diversity
and may ensure mating opportunities for the more abundant sex of alates in each species. 相似文献
12.
An experimental group of homing pigeons (Columba livia f. domestica) learned to associate food with a magnetic anomaly produced by bar magnets that were fixed to the bowl in which they received
their daily food ration in their home loft; the control group lacked this experience. Both groups were trained to search for
two hidden food depots in a rectangular sand-filled arena without obvious visual cues; for the experimental birds, these depots
were also marked with three 1.15 × 106 μT bar magnets. During the tests, there were two food depots, one marked with the magnets, the other unmarked; their position
within the arena was changed from test to test. The experimental birds searched within 10 cm of the magnetically marked depot
in 49% of the test sessions, whereas the control birds searched there in only 11% of the sessions. Both groups searched near
the control depot in 11 and 13% of the sessions, respectively. The significant preference of the magnetically marked food
depot by the experimental birds shows that homing pigeons cannot only detect a magnetic anomaly but can also use it as a cue
for locating hidden food in an open arena. 相似文献
13.
Heinze J 《Die Naturwissenschaften》2008,95(8):757-760
Workers of the ant Temnothorax nylanderi form dominance orders in orphaned colonies in which only one or a few top-ranking workers begin to produce males from unfertilized
eggs. Between one and 11 individuals initiated 80% of all aggression in 14 queenless colonies. As predicted from inclusive
fitness models (Molet M, van Baalen M, Monnin T, Insectes Soc 52:247–256, 2005), hierarchy length was found to first increase with colony size and then to level off at larger worker numbers. The frequency
and skew of aggression decreased with increasing size, indicating that rank orders are less pronounced in larger colonies. 相似文献
14.
Recruitment precision, i.e. the proportion of recruits that reach an advertised food source, is a crucial adaptation of social
bees to their environment. Studies with honeybees showed that recruitment precision is not a fixed feature, but it may be
enhanced by factors like experience and distance. However, little is known regarding the recruitment precision of stingless
bees. Hence, in this study, we examined the effects of experience and spatial distance on the precision of the food communication
system of the stingless bee Scaptotrigona mexicana. We conducted the experiments by training bees to a three-dimensional artificial patch at several distances from the colony.
We recorded the choices of individual recruited foragers, either being newcomers (foragers without experience with the advertised
food source) or experienced (foragers that had previously visited the feeder). We found that the average precision of newcomers
(95.6 ± 2.61%) was significantly higher than that of experienced bees (80.2 ± 1.12%). While this might seem counter-intuitive
on first sight, this “loss” of precision can be explained by the tendency of experienced recruits to explore nearby areas
to find new rewarding food sources after they had initially learned the exact location of the food source. Increasing the
distance from the colony had no significant effect on the precision of the foraging bees. Thus, our data show that experience,
but not the distance of the food source, affected the patch precision of S. mexicana foragers. 相似文献
15.
Lu Y Beeman RW Campbell JF Park Y Aikins MJ Mori K Akasaka K Tamogami S Phillips TW 《Die Naturwissenschaften》2011,98(9):755-761
We report that the abdominal epidermis and associated tissues are the predominant sources of male-produced pheromones in the
red flour beetle, Tribolium castaneum and, for the first time, describe the stereoisomeric composition of the natural blend of isomers of the aggregation pheromone
4,8-dimethyldecanal (DMD) in this important pest species. Quantitative analyses via gas chromatography–mass spectrometry showed
that the average amount of DMD released daily by single feeding males of T. castaneum was 878 ± 72 ng (SE). Analysis of different body parts identified the abdominal epidermis as the major source of aggregation
pheromone; the thorax was a minor source, while no DMD was detectable in the head. No internal organs or obvious male-specific
glands were associated with pheromone deposition. Complete separation of all four stereoisomers of DMD was achieved following
oxidation to the corresponding acid, derivatization with (1R, 2R)- and (1S, 2S)-2-(anthracene-2,3-dicarboximido)cyclohexanol to diastereomeric esters, and their separation on reversed-phase high-performance
liquid chromatography at −54°C. Analysis of the hexane eluate from Porapak-Q-collected volatiles from feeding males revealed
the presence of all four isomers (4R,8R)/(4R,8S)/(4S,8R)/(4S,8S) at a ratio of approximately 4:4:1:1. A walking orientation bioassay in a wind tunnel with various blends of the four synthetic
isomers further indicated that the attractive potency of the reconstituted natural blend of 4:4:1:1 was equivalent to that
of the natural pheromone and greater than that of the 1:1 blend of (4R,8R)/(4R,8S) used in commercial lures. 相似文献
16.
Tiedemann R Moll K Paulus KB Scheer M Williot P Bartel R Gessner J Kirschbaum F 《Die Naturwissenschaften》2007,94(3):213-217
Recent molecular data on the maternally inherited mitochondrial (mt) DNA have challenged the traditional view that the now
extinct Baltic sturgeon population belonged to the European sturgeon Acipenser sturio. Instead, there is evidence that American sea sturgeon Acipenser oxyrinchus historically immigrated into the Baltic Sea. In this study, we test the hypothesis that A. oxyrinchus introgressed into, rather than replaced, the A. sturio population in the Baltic. We established four single nucleotide polymorphisms (SNPs) in the nuclear MHC II antigen gene with
a species-specific SNP pattern. Using an ancient DNA approach and two independent lines of molecular evidence (sequencing
of allele-specific clones, SNaPshot), we detected both A. sturio and A. oxyrinchus alleles in the available museum material of the now extinct Baltic sturgeon population. The hybrid nature of the Baltic population
was further confirmed by very high levels of heterozygosity. It had been previously postulated that the immigration of the
cold-adapted A. oxyrinchus into the Baltic occurred during the Medieval Little Ice Age, when temperature likely dropped below the degree inducing spawning
in A. sturio. Under this scenario, our new findings suggest that the genetic mosaic pattern in the Baltic sturgeon population (oxyrinchus mtDNA, sturio and oxyrinchus MHC alleles) is possibly caused by sex-biased introgression where spawning was largely restricted to immigrating American
females, while fertilization was predominantly achieved by abundant local European males. The hybrid nature of the former
Baltic sturgeon population should be taken into account in the current reintroduction measures.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
17.
As hyperparasitoids may have a considerable influence on the control of herbivorous arthropods, analyzing the host-mediated impact of Bacillus thuringiensis-plants (Bt-plants) on hyperparasitoids is of interest. Laboratory-scale experiments were conducted in order to assess the potential effect of Bt-corn leaf material on the facultative hyperparasitoid Tetrastichus howardi (Olliff) (Hymenoptera: Eulophidae), mediated through the herbivore Chilo partellus Swinhoe (Lepidoptera: Crambidae) and its primary parasitoid Cotesia flavipes (Cameron) (Hymenoptera: Braconidae). In the Bt-group, significantly less C. flavipes larvae per host spun cocoons and pupated than in the control, and the mean fresh weight of a single C. flavipes cocoon was significantly reduced compared to the control. All C. flavipes cocoons of one host formed cocoon clusters. T. howardi females of the Bt-group parasitized significantly less cocoon clusters than in the control. Moreover, significantly fewer C. flavipes cocoons per cocoon cluster were successfully parasitized as compared to the control. As a consequence, T. howardi females of the control had more offspring than in the Bt-group. Adult female T. howardi offspring of the Bt-group weighed significantly less than in the control, but there was no significant weight difference between males of both groups. Our results suggest that transgenic insect-resistant plants could affect hyperparasitoids indirectly. However, it remains to be determined whether facultative hyperparasitoids prefer to develop as primary or secondary parasitoids under field conditions. 相似文献
18.
Coevolution is defined as specialized relationships between species that lead to a reciprocal evolutionary change. A particularly
suitable model system for studying coevolution is the interactions between obligate avian brood parasites and their hosts.
The common cuckoo (Cuculus canorus, hereafter cuckoo) is a well-known brood parasite, which utilizes a range of smaller passerines as hosts. However, warblers
of the genus Hippolais have rarely been reported as being victims of cuckoos, and furthermore, few data exist on the occurrence of antiparasite
defenses in these hosts. In this study, we examined possible host–parasite coevolution between cuckoos and eastern olivaceous
warblers (Hippolais pallida elaeica, hereafter olivaceous warblers) in three closely situated areas in northwestern Bulgaria. The olivaceous warbler has never
been reported to be a regular cuckoo host. However, the present study, carried out in 2001–2003 shows that the olivaceous
warbler is regularly and heavily parasitized by the cuckoo in this area. Parasitism rate was high (26.6%, 34/128) and consistent
among years, with some variation between areas. The cuckoo egg mimicry was moderately good, and olivaceous warbler rejection
rate of such eggs was 50%. Cuckoo eggs laid in olivaceous warbler nests had a whitish to whitish-green ground color, and the
majority appeared to be distinctly different from cuckoo eggs found in other host species in the area. The olivaceous warbler
proved to be a rather good host for cuckoos as 20.6% (7/34) of cuckoo eggs laid produced fledglings, a breeding success comparable
to other suitable hosts in Europe. This is the first in-depth study of brood parasitism in a warbler of the genus Hippolais, and cuckoos parasitizing olivaceous warblers probably represent a previously unknown gens. 相似文献
19.
In ants, winged queens that are specialized for independent colony foundation can be replaced by wingless reproductives better
adapted for colony fission. We studied this shift in reproductive strategy by comparing two Mystrium species from Madagascar using morphometry, allometry and dissections. Mystrium rogeri has a single dealate queen in each colony with a larger thorax than workers and similar mandibles that allow these queens
to hunt during non-claustral foundation. In contrast, Mystrium ‘red’ lacks winged queens and half of the female adults belong to a wingless ‘intermorph’ caste smaller and allometrically distinct
from the workers. Intermorphs have functional ovaries and spermatheca while those of workers are degenerate. Intermorphs care
for brood and a few mate and reproduce making them an all-purpose caste that takes charge of both work and reproduction. However,
their mandibles are reduced and inappropriate for hunting centipedes, unlike the workers’ mandibles. This together with their
small thorax disallow them to perform independent colony foundation, and colonies reproduce by fission. M. rogeri workers have mandibles polymorphic in size and shape, which allow for all tasks from brood care to hunting. In M. ‘red’, colonial investment in reproduction has shifted from producing expensive winged queens to more numerous helpers. M. ‘red’ intermorphs are the first case of reproductives smaller than workers in ants and illustrate their potential to diversify
their caste system for better colonial economy. 相似文献
20.
The bone-eating marine annelid Osedax consumes mainly whale bones on the deep-sea floor, but recent colonization experiments with cow bones and molecular age estimates
suggesting a possible Cretaceous origin of Osedax indicate that this worm might be able grow on a wider range of substrates. The suggested Cretaceous origin was thought to
imply that Osedax could colonize marine reptile or fish bones, but there is currently no evidence that Osedax consumes bones other than those of mammals. We provide the first evidence that Osedax was, and most likely still is, able to consume non-mammalian bones, namely bird bones. Borings resembling those produced
by living Osedax were found in bones of early Oligocene marine flightless diving birds (family Plotopteridae). The species that produced these
boreholes had a branching filiform root that grew to a length of at least 3 mm, and lived in densities of up to 40 individuals
per square centimeter. The inclusion of bird bones into the diet of Osedax has interesting implications for the recent suggestion of a Cretaceous origin of this worm because marine birds have existed
continuously since the Cretaceous. Bird bones could have enabled this worm to survive times in the Earth’s history when large
marine vertebrates other than fish were rare, specifically after the disappearance of large marine reptiles at the end-Cretaceous
mass extinction event and before the rise of whales in the Eocene. 相似文献