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1.
Most social animals have mechanisms to distinguish group members from outsiders, in part to prevent the exploitation of resources reserved for members of the group. Nevertheless, specialized thieves of the Neotropical ant, Ectatomma ruidum, also known as the ‘thieving ant’, regularly enter and steal resources from distinct, neighboring colonies. Here, we examine the mechanisms and consequences of thievery in a population of E. ruidum. We show that (1) individuals from nearby colonies were accepted more often than those from farther colonies; (2) rejection rates decreased as individuals interacted more with non‐nestmates from the same source colony; and (3) colonies that were experimentally treated to reduce thievery rates had improved productivity. The boost in productivity with thievery reduction was greater in low density populations than in high density populations. We conclude that, as in other species, thievery has negative fitness costs to E. ruidum. However, greater acceptance of neighbors than non‐neighbors and increased acceptance after habituation to non‐nestmates suggest a proximate explanation for the presence of thievery. Moreover, lower fitness costs of thievery at high nesting density, combined with observations of extraordinarily high densities of E. ruidum throughout its range, suggest there is little selection pressure among these ants to guard against thieves, thus providing an ultimate explanation why thievery persists among litter‐foraging ants. 相似文献
2.
Animals modify their foraging strategies in response to environmental changes that affect foraging performance. In some species, cleptobiosis represents an alternative strategy for resource access. The environmental factors that favor the incidence or prevalence of cleptobiosis, however, are poorly described. The cleptobiotic Neotropical ant Ectatomma ruidum is characterized by a high frequency of thievery behavior, a specific type of intraspecific cleptobiosis, in which specialized thief workers insinuate themselves into nests of neighboring colonies and intercept food items brought into these nests. Here, we evaluate how colonies adjust thievery behavior in response to food availability. We supplemented food availability and measured how the incidence and intensity of thievery responded to resource availability. We found that the incidence and intensity of thievery decline in response to supplemental food, suggesting that thievery behavior is a response to resource limitation at the population scale. This finding indicates that the phenomenon of intraspecific thievery, although a rare strategy in among colonies of social animals, is a viable alternative foraging tactic in the context of competition and food limitation. 相似文献
3.
Crop plant domestication can change plant resistance to herbivores leading to differences in pest pressure experienced by crop plants and their wild relatives. To compare resistance to herbivores between domesticated and wild fruit trees, we quantified direct resistance and indirect resistance to a pest insect, the florivorous apple blossom weevil Anthonomus pomorum (Coleoptera: Curculionidae), for the cultivated apple Malus domestica and two wild apple species, the European crab apple M. sylvestris and the exotic M. kirghisorum. We measured weevil infestation and performance (weight, sex ratio), and weevil parasitism by parasitoid wasps for different cultivars of M. domestica and for the two wild apple species. To explain weevil and parasitoid responses to different apple species, we quantified tree characteristics including nitrogen content, size of flower buds, bark roughness, tree size, tree phenology and tree position. We found significant differences in susceptibility to weevil infestation between apple species, with lowest infestation (highest apple resistance) in M. domestica and highest infestation in M. kirghisorum. The suitability of apple species also varied significantly: weevils emerging from M. sylvestris were significantly lighter than those from M. kirghisorum. Parasitism of A. pomorum by different parasitoid species was significantly higher in M. sylvestris than in M. domestica. Infestation, weevil weight and parasitism were positively related to tree characteristics: infestation to bud nitrogen content and bark roughness, weevil size to nitrogen content and bud size, and parasitism to tree height and bud density. Our study revealed marked differences between apple species in susceptibility and suitability for the pest herbivore, but also for antagonistic parasitoids. Whereas direct resistance appeared to be higher in cultivated apple, indirect resistance via parasitoids was apparently higher in wild apple trees. Our findings suggest that wild and cultivated apple trees possess different resistance traits that may be combined to optimize resistance in commercial apple cultivars. 相似文献
4.
《Insect Conservation and Diversity》2017,10(2):151-160
- Several species worldwide show rapid range retraction due to habitat degradation, and some of them have restricted distribution and specific resource needs. Such cases deserve particular attention and need urgent conservation actions to avoid extinction, and one way is to facilitate colonisation of new habitats by resource supplementation.
- Here, we investigate the changes in range distribution, during the last decade (2007–2016), of an endangered endemic damselfly, Calopteryx exul Selys, and assess the importance of its favourite host‐plant (Potamogeton nodosus) in colonisation and population dynamics in the last existing population of Algeria.
- We first used dynamic occupancy models to assess range distribution dynamics and we found that both occupancy and colonisation probabilities of the species were positively dependent on the occurrence of P. nodosus. There was also evidence that extinction probability increased with habitat disturbance but decreased with the occurrence of P. nodosus. Our experimental restoration showed that the augmentation of patches of P. nodosus increased the total number of individuals, the number of reproductive events and philopatry.
- Our study highlights the importance of insect–plant relationship in the establishment of effective restoration plans because of their implication in colonisation and extinction processes and population dynamics.
- Since most insect species from different orders and ecosystems are ecologically dependent on plants, our restoration approach may benefit a large range of threatened species and improve their conservation status.
5.
Ant–plant mutualisms are usually regarded as driven by ants defending plants against herbivores in return for plant‐produced food rewards and housing. However, ants may provide additional services. In a review of published studies on ant–pathogen–plant interactions, we investigated whether ants’ extensive hygiene measures, including the use of ant‐produced antibiotics, extend to their host plants and reduce plant pathogen loads. From 30 reported species combinations, we found that the presence of ants lead to reduced pathogen levels in 18 combinations and to increased levels in 6. On average, ants significantly reduced pathogen incidence with 59%. This effect size did not differ significantly from effect sizes reported from meta‐analyses on herbivore protection. Thus, pathogen and herbivore protection could be of equal importance in ant–plant mutualisms. Considering the abundance of these interactions, ecological impacts are potentially high. Furthermore, awareness of this service may stimulate the development of new measures to control plant diseases in agriculture. It should be noted, though, that studies were biased toward tropical ant–plant symbioses and that the literature in the field is limited at present. Future research on plant pathogens is needed to enhance our understanding of ant–plant mutualisms and their evolution. 相似文献
6.
1. Herbivores sometimes suppress plant defences. This study tested whether the presence of pea aphids (Acyrthosiphon pisum Harris) on broad bean (Vicia faba) led to decreased secretion of extrafloral nectar (EFN) which functions as an indirect plant defence against herbivores. 2. To determine effects of aphid infestation on EFN secretion, a comparison was done between EFN secretion in uninfested plants and that in plants infested by A. pisum and another aphid species (Aphis craccivora Koch). 3. When broad bean plants were infested by A. pisum, they secreted significantly smaller amounts of EFN than did uninfested plants and A. craccivora‐infested plants. There was no significant difference in EFN secretion between uninfested plants and A. craccivora‐infested plants. The number of extrafloral nectaries did not differ among the three treatments. 4. These results suggest that A. pisum reduced EFN production in broad bean plants. 相似文献
7.
Seung Ho Chung Benjamin J. Parker Frances Blow Jennifer A. Brisson Angela E. Douglas 《Molecular ecology》2020,29(4):848-858
A defining feature of the nutritional ecology of plant sap‐feeding insects is that the dietary deficit of essential amino acids (EAAs) in plant sap is supplemented by EAA‐provisioning microbial symbionts in the insect. Here, we demonstrated substantial variation in the nutritional phenotype of 208 genotypes of the pea aphid Acyrthosiphon pisum collected from a natural population. Specifically, the genotypes varied in performance (larval growth rates) on four test diets lacking the EAAs arginine, histidine and methionine or aromatic EAAs (phenylalanine and tryptophan), relative to the diet containing all EAAs. These data indicate that EAA supply from the symbiotic bacteria Buchnera can meet total aphid nutritional demand for only a subset of the EAA/aphid genotype combinations. We then correlated single nucleotide polymorphisms (SNPs) identified in the aphid and Buchnera genomes by reduced genome sequencing against aphid performance for each EAA deletion diet. This yielded significant associations between performance on the histidine‐free diet and Buchnera SNPs, including metabolism genes predicted to influence histidine biosynthesis. Aphid genetic correlates of performance were obtained for all four deletion diets, with associations on the arginine‐free diet and aromatic‐free diets dominated by genes functioning in the regulation of metabolic and cellular processes. The specific aphid genes associated with performance on different EAA deletion diets are largely nonoverlapping, indicating some independence in the regulatory circuits determining aphid phenotype for the different EAAs. This study demonstrates how variation in the phenotype of associations collected from natural populations can be applied to elucidate the genetic basis of ecologically important traits in systems intractable to traditional forward/reverse genetic techniques. 相似文献
8.
Florence Gutzwiller Franck Dedeine Wilfried Kaiser David Giron Carlos Lopez‐Vaamonde 《Ecology and evolution》2015,5(18):4049-4062
Internally feeding herbivorous insects such as leaf miners have developed the ability to manipulate the physiology of their host plants in a way to best meet their metabolic needs and compensate for variation in food nutritional composition. For instance, some leaf miners can induce green‐islands on yellow leaves in autumn, which are characterized by photosynthetically active green patches in otherwise senescing leaves. It has been shown that endosymbionts, and most likely bacteria of the genus Wolbachia, play an important role in green‐island induction in the apple leaf‐mining moth Phyllonorycter blancardella. However, it is currently not known how widespread is this moth‐Wolbachia‐plant interaction. Here, we studied the co‐occurrence between Wolbachia and the green‐island phenotype in 133 moth specimens belonging to 74 species of Lepidoptera including 60 Gracillariidae leaf miners. Using a combination of molecular phylogenies and ecological data (occurrence of green‐islands), we show that the acquisitions of the green‐island phenotype and Wolbachia infections have been associated through the evolutionary diversification of Gracillariidae. We also found intraspecific variability in both green‐island formation and Wolbachia infection, with some species being able to form green‐islands without being infected by Wolbachia. In addition, Wolbachia variants belonging to both A and B supergroups were found to be associated with green‐island phenotype suggesting several independent origins of green‐island induction. This study opens new prospects and raises new questions about the ecology and evolution of the tripartite association between Wolbachia, leaf miners, and their host plants. 相似文献
9.
Karen L. Bell Tim A. Heard Glenn Manion Simon Ferrier Rieks D. van Klinken 《Journal of Biogeography》2013,40(9):1755-1766
10.
Shereen M. ELBANNA 《Entomological Research》2011,41(4):135-141
Two different ant–Acacia ecosystems at two different sites were investigated for comparing their lifestyles. One ecosystem is at St. Katherine's Protectorate and the other at Ismailia Province, Egypt. The defense mechanisms that each Acacia tree use against browsers were investigated. Seasonal and daily abundances of ants and other herbivores on two Acacia trees were studied. The study indicated different defense mechanisms used by these two Acacia species: Acacia use both physical and chemical defense mechanisms. The efficiency of both mechanisms in defending Acacia against herbivores and why Acacia trees preferred one mechanism to the other are discussed. 相似文献
11.
Yavanna Aartsma Benjamin Leroy Wopke van der Werf Marcel Dicke Erik H. Poelman Felix J. J. A. Bianchi 《Oikos》2019,128(1):77-86
Chemical information influences the behaviour of many animals, thus affecting species interactions. Many animals forage for resources that are heterogeneously distributed in space and time, and have evolved foraging behaviour that utilizes information related to these resources. Herbivore‐induced plant volatiles (HIPVs), emitted by plants upon herbivore attack, provide information on herbivory to various animal species, including parasitoids. Little is known about the spatial scale at which plants attract parasitoids via HIPVs under field conditions and how intraspecific variation in HIPV emission affects this spatial scale. Here, we investigated the spatial scale of parasitoid attraction to two cabbage accessions that differ in relative preference of the parasitoid Cotesia glomerata when plants were damaged by Pieris brassicae caterpillars. Parasitoids were released in a field experiment with plants at distances of up to 60 m from the release site using intervals between plants of 10 or 20 m to assess parasitism rates over time and distance. Additionally, we observed host‐location behaviour of parasitoids in detail in a semi‐field tent experiment with plant spacing up to 8 m. Plant accession strongly affected successful host location in field set‐ups with 10 or 20 m intervals between plants. In the semi‐field set‐up, plant finding success by parasitoids decreased with increasing plant spacing, differed between plant accessions, and was higher for host‐infested plants than for uninfested plants. We demonstrate that parasitoids can be attracted to herbivore‐infested plants over large distances (10 m or 20 m) in the field, and that stronger plant attractiveness via HIPVs increases this distance (up to at least 20 m). Our study indicates that variation in plant traits can affect attraction distance, movement patterns of parasitoids, and ultimately spatial patterns of plant–insect interactions. It is therefore important to consider plant‐trait variation in HIPVs when studying animal foraging behaviour and multi‐trophic interactions in a spatial context. 相似文献
12.
13.
Luisa Amo Jeroen J. Jansen Nicole M. van Dam Marcel Dicke Marcel E. Visser 《Ecology letters》2013,16(11):1348-1355
Arthropod herbivory induces plant volatiles that can be used by natural enemies of the herbivores to find their prey. This has been studied mainly for arthropods that prey upon or parasitise herbivorous arthropods but rarely for insectivorous birds, one of the main groups of predators of herbivorous insects such as lepidopteran larvae. Here, we show that great tits (Parus major) discriminate between caterpillar‐infested and uninfested trees. Birds were attracted to infested trees, even when they could not see the larvae or their feeding damage. We furthermore show that infested and uninfested trees differ in volatile emissions and visual characteristics. Finally, we show, for the first time, that birds smell which tree is infested with their prey based on differences in volatile profiles emitted by infested and uninfested trees. Volatiles emitted by plants in response to herbivory by lepidopteran larvae thus not only attract predatory insects but also vertebrate predators. 相似文献
14.
T.J.A. Bruce 《The Annals of applied biology》2014,164(3):348-353
Glucosinolates are sulphur‐containing secondary metabolites characteristic of Brassicaceous plants. Glucosinolate breakdown products, which include isothiocyanates, are released following tissue damage when hydrolytic enzymes act on them. The isothiocyanates have toxic effects on generalist herbivores when they attempt to feed on oilseed rape, Brassica napus, and also function as repellents. However, specialist herbivores such as Brevicoryne brassicae aphids, flea beetles, Psylliodes chrysocephala and the Lepidopteran pest, Pieris rapae, are adapted to the presence of glucosinolates and thrive on plants containing them. They may do this by avoiding tissue damage to prevent the formation of isothiocyanates or by metabolising or tolerating glucosinolates. For many specialist herbivores, the isothiocyanates function as attractants and glucosinolates can even be sequestered for defence against predatory insects. Thus, these herbivores have evolved resistance to host‐plant secondary metabolites and this type of evolutionary history may have given some insects an enhanced ability to adapt to xenobiotics. In an agricultural context, this may make pests better able to evolve resistance to artificially applied pesticides. The effect of increased glucosinolate content in making oilseed rape cultivars more susceptible to specialist pests was highlighted in a seminal article in the Annals of Applied Biology in 1995. This review of the literature considers developments in this area since then. 相似文献
15.
Ulrich G. Mueller Heather D. Ishak Sofia M. Bruschi Chad C. Smith Jacob J. Herman Scott E. Solomon Alexander S. Mikheyev Christian Rabeling Jarrod J. Scott Michael Cooper Andre Rodrigues Adriana Ortiz Carlos R. F. Brandão John E. Lattke Fernando C. Pagnocca Stephen A. Rehner Ted R. Schultz Heraldo L. Vasconcelos Rachelle M. M. Adams Martin Bollazzi Rebecca M. Clark Anna G. Himler John S. LaPolla Inara R. Leal Robert A. Johnson Flavio Roces Jeffrey Sosa‐Calvo Rainer Wirth Maurício Bacci Jr 《Molecular ecology》2017,26(24):6921-6937
Leafcutter ants propagate co‐evolving fungi for food. The nearly 50 species of leafcutter ants (Atta, Acromyrmex) range from Argentina to the United States, with the greatest species diversity in southern South America. We elucidate the biogeography of fungi cultivated by leafcutter ants using DNA sequence and microsatellite‐marker analyses of 474 cultivars collected across the leafcutter range. Fungal cultivars belong to two clades (Clade‐A and Clade‐B). The dominant and widespread Clade‐A cultivars form three genotype clusters, with their relative prevalence corresponding to southern South America, northern South America, Central and North America. Admixture between Clade‐A populations supports genetic exchange within a single species, Leucocoprinus gongylophorus. Some leafcutter species that cut grass as fungicultural substrate are specialized to cultivate Clade‐B fungi, whereas leafcutters preferring dicot plants appear specialized on Clade‐A fungi. Cultivar sharing between sympatric leafcutter species occurs frequently such that cultivars of Atta are not distinct from those of Acromyrmex. Leafcutters specialized on Clade‐B fungi occur only in South America. Diversity of Clade‐A fungi is greatest in South America, but minimal in Central and North America. Maximum cultivar diversity in South America is predicted by the Kusnezov–Fowler hypothesis that leafcutter ants originated in subtropical South America and only dicot‐specialized leafcutter ants migrated out of South America, but the cultivar diversity becomes also compatible with a recently proposed hypothesis of a Central American origin by postulating that leafcutter ants acquired novel cultivars many times from other nonleafcutter fungus‐growing ants during their migrations from Central America across South America. We evaluate these biogeographic hypotheses in the light of estimated dates for the origins of leafcutter ants and their cultivars. 相似文献
16.
Angélica Miamoto Monique Thiara Rodrigues e Silva Claudia Regina Dias‐Arieira Heriksen Higashi Puerari 《Journal of Phytopathology》2017,165(10):635-640
Nematodes stand out among the main soya bean yield limiting factors due to limitations in the main control methods, mainly when they are applied alone. Given the need of finding new control techniques, the aim of this study was to assess the efficiency of products based on biological control agents and on nutrients or products showing potential to induce resistance for Pratylenchus brachyurus and Meloidogyne javanica control in soya bean plants. The experiments were conducted in a greenhouse; nine treatments with six repetitions for each nematode were assessed in two distinct periods. Overall, all treatments have shown potential to control the nematodes in at least one experiment, mainly the ones containing biological control agents (Trichoderma and Bacillus). The vegetative development results were inconclusive; however, some products have shown potential to improve the growth of infected plants. 相似文献
17.
Although changes in phenology and species associations are relatively well‐documented responses to global warming, the potential interactions between these phenomena are less well understood. In this study, we investigate the interactions between temperature, phenology (in terms of seasonal timing of larval growth) and host plant use in the polyphagous butterfly Polygonia c‐album. We found that the hierarchy of larval performance on three natural host plants was not modified by a temperature increase as such. However, larval performance on each host plant and temperature treatment was affected by rearing season. Even though larvae performed better at the higher temperature regardless of the time of the rearing, relative differences between host plants changed with the season. For larvae reared late in the season, performance was always better on the herbaceous plant than on the woody plants. In this species, it is likely that a prolonged warming will lead to a shift from univoltinism to bivoltinism. The demonstrated interaction between host plant suitability and season means that such a shift is likely to lead to a shift in selective regime, favoring specialization on the herbaceous host. Based on our result, we suggest that host range evolution in response to temperature increase would in this species be highly contingent on whether the population undergoes a predicted shift from one to two generations. We discuss the effect of global warming on species associations and the outcome of asynchrony in rates of phenological change. 相似文献
18.
1. In annual plant communities, the seed bank determines each generation's potential emergence and any factor that influences it could alter community structure. Harvester ants are common seed predators that may cause seed sources and seed rain composition to vary. 2. In semi‐arid shrubland of the Negev desert of Israel, we hypothesised that the positive effects of dense vegetation on nests of the harvester ant Messor ebeninus Sant. would outweigh reduction by granivory. 3. To test whether nests were seed sources, we removed vegetation on 10 of 20 sampled nests prior to seeding. We tested the interaction between seed sources and granivory by locating seed traps at three locations: nests, foraging trails, and unvisited areas. Trapped seeds were recorded during spring and summer dispersal. Plant recruitment from the altered seed bank was recorded the following spring. 4. During April, seeds were more abundant near nests than the other locations and at uncut compared with cut nests. Foraging trails had fewer species and higher equitability compared with nests or unvisited areas. May and June to August had highest species richness at nests, but richness of cut and uncut nests were similar. Ordination of plant recruitment showed slightly lower vegetation community variation by diminished species in the cut seed bank. 5. While intact nest vegetation initially had high abundance of locally deposited seeds, it apparently blocked wind‐dispersed seeds later in the summer. Conversely, granivory reduced seed species richness only on trails and decreased dominance structure by preferential removal of some species. 相似文献
19.
- Plants usually interact with other plants, and the outcome of such interaction ranges from facilitation to competition depending on the identity of the plants, including their sexual expression. Arbuscular mycorrhizal (AM) fungi have been shown to modify competitive interactions in plants. However, few studies have evaluated how AM fungi influence plant intraspecific and interspecific interactions in dioecious species.
- The competitive abilities of female and male plants of Antennaria dioica were examined in a greenhouse experiment. Females and males were grown in the following competitive settings: (i) without competition, (ii) with intrasexual competition, (iii) with intersexual competition, and (iv) with interspecific competition by Hieracium pilosella – a plant with similar characteristics to A. dioica. Half of the pots were grown with Claroideoglomus claroideum, an AM fungus isolated from the same habitat as the plant material. We evaluated plant survival, growth, flowering phenology, and production of AM fungal structures.
- Plant survival was unaffected by competition or AM fungi. Competition and the presence of AM fungi reduced plant biomass. However, the sexes responded differently to the interaction between fungal and competition treatments. Both intra‐ and interspecific competition results were sex‐specific, and in general, female performance was reduced by AM colonization. Plant competition or sex did not affect the intraradical structures, extraradical hyphae, or spore production of the AM fungus.
- These findings suggest that plant sexual differences affect fundamental processes such as competitive ability and symbiotic relationships with AM fungi.
20.
The role of wildland weeds that serve as alternate hosts for insect pests has not been directly examined for the potential to sustain pest populations or facilitate pest outbreaks. The development of weed biological control programmes is also complicated by weed species that are closely related to economically important or native plants, especially rare or special status species. In recent surveys in southern California, USA, we found a newly introduced insect pest of cole crops, Bagrada hilaris Burmeister (Bagrada bug), feeding on Brassicaceae weeds in riparian areas adjacent to agricultural fields where cole crops are routinely grown. Insect populations grew to levels well over action thresholds and caused severe damage to populations of the invasive weed, Lepidium latifolium (perennial pepperweed). The numerical response of B. hilaris on L. latifolium and other Brassicaceae weeds in natural areas may pose a significant challenge to effectively managing pest populations in crops. However, the accidental introduction of this insect provides the opportunity to examine plant–insect interactions with important implications for development of biologically based control methods for weeds. 相似文献