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1.
Braz J Biol ; 83: e243651, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34431904

RESUMO

Acacia auriculiformis A. Cunn. Ex Benth. (Fabaceae), a non-native pioneer species in Brazil with fast growth and rusticity, is used in restoration programs. Our goal was to assess during a 24-month survey the pattern of arthropods (phytophagous insects, bees, spiders, and predator insects) on the leaf surfaces of A. auriculiformis saplings. Fourteen species of phytophagous, two of bees and eleven of predators were most abundant on the adaxial surface. The values of the ecological indexes (abundance, diversity, and species richness) and the rarefaction, and k-dominance curves of phytophagous, bees and arthropod predators were highest on the adaxial leaf surface of A. auriculiformis. The k-dominance and abundance of Aleyrodidae (Hemiptera) (both leaf surfaces), the native stingless bee Tetragonisca angustula Latreille (Hymenoptera: Apidae) (both leaf surfaces) and the ant Brachymyrmex sp. (adaxial surface) and Pheidole sp. (Hymenoptera: Formicidae) (abaxial surface) were the highest between the taxonomic groups of phytophagous, bees, and predators, respectively on A. auriculiformis saplings. The ecological indexes and rarefaction, abundance, and k-dominance curves of phytophagous insects, bees, and predators were highest on the adaxial leaf surface. The preference of phytophagous insects for the adaxial leaf surface is probably due to the lower effort required to move on this surface. Understanding the arthropod preferences between leaf surfaces may help to develop sampling and pest management plans for the most abundant phytophagous insects on A. auriculiformis saplings. Also, knowledge on the preference pattern of bees and predators may be used to favour their conservation.


Assuntos
Acacia , Formigas , Artrópodes , Animais , Abelhas , Insetos , Folhas de Planta
2.
J Insect Sci ; 21(4)2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34436597

RESUMO

Worker division of labor is a defining trait in social insects. Many species are characterized by having behavioral flexibility where workers perform non-typical tasks for their age depending on the colony's needs. Worker division of labor and behavioral flexibility were examined in the little fire ant Wasmannia auropunctata (Roger, 1863), for which age-related division of labor has been found. Young workers perform nursing duties which include tending of brood and queens, and colony defense, while older workers forage. When nurses were experimentally removed from the colony, foragers were observed carrying out nursing and colony defense duties, yet when foragers were removed nurses did not forage precociously. We also administered juvenile hormone analog, methoprene, to workers. When methoprene was applied, foragers increased their nursing and defense activities while nurses became mainly idle. The behavioral flexibility of foragers of the little fire ant may be evidence of an expansion of worker's repertoires as they age; older workers can perform tasks they have already done in their life while young individuals are not capable of performing tasks ahead of time. This may be an important adaptation associated with the success of this ant as an invasive species.


Assuntos
Formigas , Hormônios Juvenis , Comportamento Social , Animais , Formigas/efeitos dos fármacos , Formigas/fisiologia , Espécies Introduzidas , Hormônios Juvenis/farmacologia , Hormônios Juvenis/fisiologia , Metoprene/farmacologia
3.
Biol Lett ; 17(8): 20210316, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34376075

RESUMO

Animals may develop mutualistic associations with other species, whereby prey offer resources or services in exchange for protection from predators. Alternatively, prey may offer resources or services directly to their would-be predators in exchange for their lives. The latter may be the case of hemipterans that engage in mutualistic interactions with ants by offering a honeydew reward. We test the extent to which a honeydew offering versus partner recognition may play a role as proximate mechanisms deterring ants from predating upon their hemipteran partners. We showed that, when presented with a choice between a hemipteran partner and an alternative prey type, mutualist ants were less likely to attack and more likely to remain probing their hemipteran partners. This occurred even in the absence of an immediate sugary reward, suggesting either an evolved or learned partner recognition response. To a similar extent, however, ants were also less likely to attack the alternative prey type when laced with honey as a proxy for a honeydew reward. This was the case even after the honey had been depleted, suggesting an ability of ants to recognize new potential sources of sugars. Either possibility suggests a degree of innate or learned partner recognition.


Assuntos
Formigas , Simbiose , Animais
4.
Ecol Lett ; 24(11): 2439-2451, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34418263

RESUMO

Foraging trails of leafcutter colonies are iconic scenes in the Neotropics, with ants collecting freshly cut plant fragments to provision a fungal food crop. We hypothesised that the fungus-cultivar's requirements for macronutrients and minerals govern the foraging niche breadth of Atta colombica leafcutter ants. Analyses of plant fragments carried by foragers showed how nutrients from fruits, flowers and leaves combine to maximise cultivar performance. While the most commonly foraged leaves delivered excess protein relative to the cultivar's needs, in vitro experiments showed that the minerals P, Al and Fe may expand the leafcutter foraging niche by enhancing the cultivar's tolerance to protein-biased substrates. A suite of other minerals reduces cultivar performance in ways that may render plant fragments with optimal macronutrient blends unsuitable for provisioning. Our approach highlights how the nutritional challenges of provisioning a mutualist can govern the multidimensional realised niche available to a generalist insect herbivore.


Assuntos
Formigas , Animais , Fungos , Herbivoria , Folhas de Planta , Simbiose
5.
Environ Sci Pollut Res Int ; 28(39): 54362-54382, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34405331

RESUMO

Biotic invasions can predominantly alter the dynamics, composition, functions, and structure of natural ecosystems. Social insects, particularly ants, are among the most damaging invasive alien species. Invasive ant species are among the supreme threats to ecosystems. There are about 23 species of invasive ants recorded worldwide, according to the ant invasive databases. The ecological impacts of invasive ants comprise predation, hybridization, and competition with native species that changes the ecosystem processes with the biodiversity loss and upsurge of pests. The effects of invasion on native fauna in the same habitats might be catastrophic for the native community through various ecological mechanisms, e.g., habitat disturbance, resource competition, limiting the foraging activity of native species, and various other indirect mechanisms of invasive species. Invasive species may have harmful impacts on habitats and devastating effects on natural flora and fauna, and stopping these new species from being introduced is the most effective way to deter future invasions and maintain biodiversity. This paper reviews the literature to evaluate the effects of invasive ant species on the native species, including vertebrates, invertebrates, and plants sharing the same habitats as the non-native species under global environmental changes. We also highlighted the various management strategies that could be adopted in minimizing the adverse effects of these invasive ant species on the natural ecosystem. To this end, strategies that could regulate the mode and rate of invasion by these alien ant species are the most effective ways to deter future invasions and maintain biodiversity.


Assuntos
Formigas , Espécies Introduzidas , Animais , Ecossistema
6.
J Exp Biol ; 224(7)2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-34424967

RESUMO

During the evolution of social insects, not only did life-history traits diverge, with queens becoming highly fecund and long lived compared with their sterile workers, but also individual traits lost their importance compared with colony-level traits. In solitary animals, fecundity is largely influenced by female size, whereas in eusocial insects, colony size and queen number can affect the egg-laying rate. Here, we focused on the ant Temnothorax rugatulus, which exhibits two queen morphs varying in size and reproductive strategy, correlating with their colony's social organization. We experimentally tested the influence of social structure, colony and body size on queen fecundity and investigated links between body size, metabolic rate and survival under paraquat-induced oxidative stress. To gain insight into the molecular physiology underlying the alternative reproductive strategies, we analysed fat body transcriptomes. Per-queen egg production was lower in polygynous colonies when fecundity was limited by worker care. Colony size was a determinant of fecundity rather than body size or queen number, highlighting the super-organismal properties of these societies. The smaller microgynes were more frequently fed by workers and exhibited an increase in metabolic activity, yet they were similarly resistant to oxidative stress. Small queens differentially expressed metabolic genes in the fat body, indicating that shifts in molecular physiology and resource availability allow microgyne queens to compensate for their small size with a more active metabolism without paying increased mortality costs. We provide novel insights into how life-history traits and their associations were modified during social evolution and adapted to queen reproductive strategies.


Assuntos
Formigas , Traços de História de Vida , Animais , Formigas/genética , Feminino , Fertilidade , Humanos , Insetos , Reprodução
7.
Ecology ; 102(10): e03476, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34346070

RESUMO

Invasive species threaten biodiversity, ecosystem function, and human health, but the long-term drivers of invasion dynamics remain poorly understood. We use data from a 28-yr ongoing survey of a Northern California ant community invaded by the Argentine ant (Linepithema humile) to investigate the influence of abiotic and biotic factors on invasion dynamics. We found that the distribution of L. humile retracted following an extreme drought that occurred in the region from 2012 to 2015. The distribution of several native ant species also contracted, but overall native ant diversity was higher after the drought and for some native ant species, distributions expanded over the 28-yr survey period. Using structural equation models, we found the strongest impact on the distribution of L. humile was from direct effects of climate, namely, cumulative precipitation and summer maximum temperatures, with only a negligible role for biotic resistance and indirect effects of climate mediated by native ants. The increasing drought and high temperature extremes projected for northern California because of anthropogenic-driven climate change may limit the spread, and possibly the impact, of L. humile in invaded regions. The outcome will depend on the response of native ant communities to these climatic stressors.


Assuntos
Formigas , Animais , Secas , Ecossistema , Humanos , Espécies Introduzidas , Estações do Ano
8.
J Exp Biol ; 224(15)2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34342358

RESUMO

Animals are known to exhibit different walking behaviors in hilly habitats. For instance, cats, rats, squirrels, tree frogs, desert iguana, stick insects and desert ants were observed to lower their body height when traversing slopes, whereas mound-dwelling iguanas and wood ants tend to maintain constant walking kinematics regardless of the slope. This paper aims to understand and classify these distinct behaviors into two different strategies against toppling for climbing animals by looking into two factors: (i) the torque of the center of gravity (CoG) with respect to the critical tipping axis, and (ii) the torque of the legs, which has the potential to counterbalance the CoG torque. Our comparative locomotion analysis on level locomotion and inclined locomotion exhibited that primarily only one of the proposed two strategies was chosen for each of our sample species, despite the fact that a combined strategy could have reduced the animal's risk of toppling over even more. We found that Cataglyphis desert ants (species Cataglyphis fortis) maintained their upright posture primarily through the adjustment of their CoG torque (geometric strategy), and Formica wood ants (species Formica rufa), controlled their posture primarily by exerting leg torques (adhesive strategy). We further provide hints that the geometric strategy employed by Cataglyphis could increase the risk of slipping on slopes as the leg-impulse substrate angle of Cataglyphis hindlegs was lower than that of Formica hindlegs. In contrast, the adhesion strategy employed by Formica front legs not only decreased the risk of toppling but also explained the steeper leg-impulse substrate angle of Formica hindlegs which should relate to more bending of the tarsal structures and therefore to more microscopic contact points, potentially reducing the risk of hindleg slipping.


Assuntos
Adesivos , Formigas , Animais , Fenômenos Biomecânicos , Gatos , Locomoção , Ratos , Caminhada
9.
J Exp Biol ; 224(15)2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34357377

RESUMO

Associative learning relies on the detection of coincidence between a stimulus and a reward or punishment. In the insect brain, this process is carried out in the mushroom bodies under the control of octopaminergic and dopaminergic neurons. It was assumed that appetitive learning is governed by octopaminergic neurons, while dopamine is required for aversive learning. This view has recently been challenged: both neurotransmitters are involved in both types of learning in bees and flies. Here, we tested which neurotransmitters are required for appetitive learning in ants. We trained Lasius niger workers to discriminate two mixtures of linear hydrocarbons and to associate one of them with a sucrose reward. We analysed the walking paths of the ants using machine learning and found that the ants spent more time near the rewarded odour than near the other, a preference that was stable for at least 24 h. We then treated the ants before learning with either epinastine, an octopamine receptor blocker, or flupentixol, a dopamine receptor blocker. Ants with blocked octopamine receptors did not prefer the rewarded odour. Octopamine signalling is thus necessary for appetitive learning of olfactory cues, probably because it signals information about odours or reward to the mushroom body. In contrast, ants with blocked dopamine receptors initially learned the rewarded odour but failed to retrieve this memory 24 h later. Dopamine is thus probably required for long-term memory consolidation, independent of short-term memory formation. Our results show that appetitive olfactory learning depends on both octopamine and dopamine signalling in ants.


Assuntos
Formigas , Octopamina , Animais , Comportamento Apetitivo , Abelhas , Condicionamento Clássico , Receptores Dopaminérgicos , Olfato
10.
J Insect Sci ; 21(4)2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34297812

RESUMO

Tapinoma indicum (Forel) (Hymenoptera: Formicidae) is a nuisance pest in Asia countries. However, studies on T. indicum are limited, especially in the field of molecular biology, to investigate the species characteristic at the molecular level. This paper aims to provide valuable genetic markers as tools with which to study the T. indicum population. In this study, a total of 143,998 microsatellite markers were developed based on the 2.61 × 106 microsatellites isolated from T. indicum genomic DNA sequences. Fifty selected microsatellite markers were amplified with varying numbers of alleles ranging from 0 to 19. Seven out of fifty microsatellite markers were characterized for polymorphism with the Hardy-Weinberg equilibrium (HWE) and linkage disequilibrium (LD) analysis. All seven microsatellite markers demonstrated a high polymorphic information content (PIC) value ranging from 0.87 to 0.93, with a mean value of 0.90. There is no evidence of scoring errors caused by stutter peaks, no large allele dropout, and no linkage disequilibrium among the seven loci; although loci Ti-Tr04, Ti-Tr09, Ti-Te04, Ti-Te13, and Ti-Pe5 showed signs of null alleles and deviation from the HWE due to excessive homozygosity. In conclusion, a significant amount of microsatellite markers was developed from the data set of next-generation sequencing, and seven of microsatellite markers were validated as informative genetic markers that can be utilized to study the T. indicum population.


Assuntos
Formigas/genética , Repetições de Microssatélites/genética , Animais , Marcadores Genéticos , Genoma de Inseto , Sequenciamento de Nucleotídeos em Larga Escala , Controle de Pragas , Polimorfismo Genético
12.
Behav Processes ; 190: 104460, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34256142

RESUMO

Eusocial insects depend on their colonies, and it is therefore clear why isolation triggers many negative effects on isolated individuals. Here, we examined the effect of social isolation on the desert ant Cataglyphis niger, asking whether isolation, either with access to food or under starvation, impairs survival, and whether isolation modifies movement activity and digging to bypass an obstacle. Social isolation led to shorter survival but only when food was provided. This effect might be due to food not being digested correctly under isolation. Although isolated ant workers were more active immediately post isolation than 2-24 hours later, their movement moderately increased two days post isolation. We suggest that the changes in movement activity are adaptive: first, the worker increases activity intended to reunite it with the lost colony. Then, when the colony is not found, it reduces activity to conserve energy. It later increases activity as a final attempt to detect the colony. We expected isolated workers to dig faster to bypass an obstacle, but we did not detect any effect on digging behavior. We demonstrate here the complex effects of isolation on survival and movement activity, in interaction with additional factors - feeding and isolation duration.


Assuntos
Formigas , Isolamento Social , Animais , Alimentos , Humanos , Movimento , Comportamento Social
13.
Genetica ; 149(4): 203-215, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34282482

RESUMO

Fire ants (Solenopsis invicta Buren in J Ga Entomol Soc 7:1-26, 1972), an invasive alien ant species, first spread from South America to the United States in the 1930s, the southern part of the United States by the end of the twentieth century, Oceania, Taiwan, and China in the twenty-first century, and finally to Japan and South Korea in 2017. As these ants have significant negative economic, human health, and environmental impacts, the purpose of this research was to accumulate cytogenetic information regarding fire ants and provide basic data for developing management strategies for their control. Fire ants were collected from invasive populations from Taiwan, Florida (USA), and Buenos Aires (Argentina), and a native population from Puerto Iguazu (Argentina), their point of origination, and analyzed with regard to chromosome number, morphology, and polyploidy, silver-stained nucleolar organizer regions (Ag-NORs), and 18S rDNA and telomere fluorescence in situ hybridization (FISH). The results showed that (1) fire ants from invaded populations differed in chromosome morphology compared to those from native populations; (2) the Florida and Taiwanese fire ant populations evinced greater variability in chromosome numbers and polyploidy variations; (3) the Taiwanese population exhibited significantly increased Ag-NOR signals in interphase cells, with signal number significantly positively correlating with distance from native populations; and (4) substantial diversity of signals was also apparent following 18S rDNA and telomere FISH analyses. Variation in these characteristics were hypothesized to be due to (1) the effect of hybridizations and interbreeding between closely related species or genetically distant populations, and (2) the potential effect of large amounts of insecticides sprayed for pest control.


Assuntos
Formigas/genética , Cromossomos de Insetos/genética , Poliploidia , Animais , Espécies Introduzidas , Região Organizadora do Nucléolo/genética , RNA Ribossômico 18S/genética , Telômero/genética
15.
J Exp Biol ; 224(11)2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34086906

RESUMO

Learning allows animals to respond to changes in their environment within their lifespan. However, many responses to the environment are innate, and need not be learned. Depending on the level of cognitive flexibility an animal shows, such responses can either be modified by learning or not. Many ants deposit pheromone trails to resources, and innately follow such trails. Here, we investigated cognitive flexibility in the ant Lasius niger by asking whether ants can overcome their innate tendency and learn to avoid conspecific pheromone trails when these predict a negative stimulus. Ants were allowed to repeatedly visit a Y-maze, one arm of which was marked with a strong but realistic pheromone trail and led to a punishment (electric shock and/or quinine solution), and the other arm of which was unmarked and led to a 1 mol l-1 sucrose reward. After ca. 10 trials, ants stopped relying on the pheromone trail, but even after 25 exposures they failed to improve beyond chance levels. However, the ants did not choose randomly: rather, most ants began to favour just one side of the Y-maze, a strategy which resulted in more efficient food retrieval over time, when compared with the first visits. Even when trained in a go/no-go paradigm which precludes side bias development, ants failed to learn to avoid a pheromone trail. These results show rapid learning flexibility towards an innate social signal, but also demonstrate a rarely seen hard limit to this flexibility.


Assuntos
Formigas , Animais , Cognição , Comportamento Alimentar , Aprendizagem , Feromônios
16.
Zootaxa ; 4969(1): 5460, 2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-34186943

RESUMO

A new species of ant resembling sac spider of the subfamily Castianeirinae, Myrmecotypus haddadi sp. nov. is described from the Sub-Andean area at the Bolivian orocline. The species was collected from low herbaceous vegetation along the edges of the Chiquitano and Cerradao forest.


Assuntos
Formigas/classificação , Aranhas , Animais , Bolívia , Florestas
17.
J Insect Sci ; 21(3)2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34137894

RESUMO

Worldwide, two of the most harmful invasive ants typical of disturbed sites are Solenopsis geminata (Fabricius) and Wasmannia auropunctata (Roger). Both are natives of the Neotropics and are widely distributed all over the tropics. Within its original geographic range, there are few data on its abundance and potential damage to natural ecosystems. In this study, we recorded their abundance and relationships to diversity and richness of soil ant communities in two localities with different amount of forested area (López Mateos, LM 77% and Venustiano Carranza, VC 27%), at Los Tuxtlas reserve. In each locality, four land use systems (LUS) were sampled: tropical rain forests, agroforestry plantations, annual crops, and pastures. Data were gathered from 360 ant samples obtained from litter squares, pitfall traps, and soil monoliths in 40 sampling points (20 per locality, and five per LUS). Solenopsis geminata was more abundant in LM than in VC; the opposite trend was observed for W. auropunctata. In LM, S. geminata was more abundant in crops than in the other LUS, whereas W. auropunctata tended to have higher abundances in less managed sites of both localities. Abundance and species richness of ant communities were higher in LM than in VC. At regional and local levels, we found negative relationships between the abundance of S. geminata and species richness; the inverse pattern was found for W. auropunctata. We conclude that at Los Tuxtlas, W. auropunctata can be considered as a typical dominant native species, whereas S. geminata is the common exotic invasive ant.


Assuntos
Formigas , Ecossistema , Distribuição Animal , Animais , Produtos Agrícolas , Monitorização de Parâmetros Ecológicos , Florestas , Espécies Introduzidas , México , Dinâmica Populacional
18.
Zootaxa ; 4985(3): 403413, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34186800

RESUMO

Here we describe and illustrate Syllophopsis peetersi sp. nov. from Silent Valley National Park, a biodiversity hotspot region of the Western Ghats of India. The discovery also marks a first native report of the genus from the Indian subcontinent. Scanning Electron Microscopy (SEM) analysis was carried out to elucidate the general morphology and sensilla of the new species. The new species is similar to congeners from Madagascar, but with larger differences from species that occur elsewhere.


Assuntos
Formigas/classificação , Animais , Formigas/ultraestrutura , Biodiversidade , Índia , Microscopia Eletrônica de Varredura
19.
Zootaxa ; 4980(3): 575582, 2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34186963

RESUMO

Cylindera (Cylindera) julietae sp. nov. (Cicindelidae: Cicindelini) is described as new for science from southern Bolivia. The new species is compared to a similar species Cylindera (Cylindera) confluentesignata (W. Horn, 1915). Colour photographs of habitus, habitat and diagnostic characters of the two similar species are presented. The behaviour of adults of the new species, imitating that of co-occurring ants, is discussed.


Assuntos
Comportamento Animal , Besouros , Animais , Formigas/fisiologia , Bolívia , Besouros/classificação , Besouros/fisiologia , Ecossistema , Especificidade da Espécie
20.
J R Soc Interface ; 18(179): 20210318, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34102082

RESUMO

Ants show remarkable ecological and evolutionary success due to their social life history and division of labour among colony members. In some lineages, the worker force became subdivided into morphologically distinct individuals (i.e. minor versus major workers), allowing for the differential performance of particular roles in the colony. However, the functional and ecological significance of these morphological differences are not well understood. Here, we applied finite element analysis (FEA) to explore the biomechanical differences between major and minor ant worker mandibles. Analyses were carried out on mandibles of two Pheidole species, a dimorphic ant genus. We tested whether major mandibles evolved to minimize stress when compared to minors using combinations of the apical tooth and masticatory margin bites under strike and pressure conditions. Majors performed better in pressure conditions yet, contrary to our expectations, minors performed better in strike bite scenarios. Moreover, we demonstrated that even small morphological differences in ant mandibles might lead to substantial differences in biomechanical responses to bite loading. These results also underscore the potential of FEA to uncover biomechanical consequences of morphological differences within and between ant workers.


Assuntos
Formigas , Animais , Evolução Biológica , Humanos , Mandíbula
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