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1.
Braz. j. biol ; 84: e253218, 2024. tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1355863

RESUMO

Abstract Indices are used to help on decision-making. This study aims to develop and test an index, which can determine the loss (e.g., herbivorous insects) and solution (e.g., natural enemies) sources. They will be classified according to their importance regarding the ability to damage or to reduce the source of damage to the system when the final production is unknown. Acacia auriculiformis (Fabales: Fabaceae), a non-native pioneer species in Brazil with fast growth and rusticity, is used in restoration programs, and it is adequate to evaluate a new index. The formula was: Percentage of the Importance Indice-Production Unknown (% I.I.-PU) = [(ks1 x c1 x ds1)/Σ (ks1 x c1 x ds1) + (ks2 x c2 x ds2) + (ksn x cn x dsn)] x 100. The loss sources Aethalion reticulatum L., 1767 (Hemiptera: Aethalionidae), Aleyrodidae (Hemiptera), Stereoma anchoralis Lacordaire, 1848 (Coleoptera: Chrysomelidae), and Tettigoniidae, and solution sources Uspachus sp. (Araneae: Salticidae), Salticidae (Araneae), and Pseudomyrmex termitarius (Smith, 1877) (Hymenoptera: Formicidae) showed the highest % I.I.-PU on leaves of A. auriculiformis saplings. The number of Diabrotica speciosa Germar, 1824 (Coleoptera: Chrysomelidae) was reduced per number of Salticidae; that of A. reticulatum that of Uspachus sp.; and that of Cephalocoema sp. (Orthoptera: Proscopiidae) that of P. termitarius on A. auriculiformis saplings. However, the number of Aleyrodidae was increased per number of Cephalotes sp. (Hymenoptera: Formicidae) and that of A. reticulatum that of Brachymyrmex sp. (Hymenoptera: Formicidae) on A. auriculiformis saplings. The A. reticulatum damage was reduced per number of Uspachus sp., but the Aleyrodidae damage was increased per number of Cephalotes sp., totaling 23.81% of increase by insect damages on A. auriculiformis saplings. Here I show and test the % I.I.-PU. It is an new index that can detect the loss or solution sources on a system when production is unknown. It can be applied in some knowledge areas.


Resumo Índices são usados para ajudar na tomada de decisões. Este trabalho teve como objetivo desenvolver e testar um índice capaz de determinar fontes de perda (ex.: insetos herbívoros) e de solução (ex.: inimigos naturais). Eles serão classificados de acordo com sua importância quanto a habilidade de danificar ou reduzir danos no sistema, quando a produção final é desconhecida. Acacia auriculiformis (Fabales: Fabaceae), uma espécie pioneira não nativa do Brasil com rápido crescimento e rusticidade, usada em programas de restauração, é adequada para avaliar um novo índice. A fórmula foi: Porcentagem de Índice de Importância-Produção Desconhecida (% I.I.-PD) = [(ks1 x c1 x ds1)/Σ (ks1 x c1 x ds1) + (ks2 x c2 x ds2) + (ksn x cn x dsn)] x 100. As fontes de perda Aethalion reticulatum L., 1767 (Hemiptera: Aethalionidae), Aleyrodidae (Hemiptera), Stereoma anchoralis Lacordaire, 1848 (Coleoptera: Chrysomelidae) e Tettigoniidae, e as fontes de solução Uspachus sp. (Araneae: Salticidae), Salticidae (Araneae) e Pseudomyrmex termitarius (Smith, 1877) (Hymenoptera: Formicidae) apresentaram maiores % I.I.-PD nas folhas das mudas de A. auriculiformis. O número de Diabrotica speciosa Germar, 1824 (Coleoptera: Chrysomelidae) foi reduzido pelo número de Salticidae; o de A. reticulatum pelo de Uspachus sp.; e o de Cephalocoema sp. (Orthoptera: Proscopiidae) pelo de P. termitarius em mudas de A. auriculiformis. Entretanto, o número de Aleyrodidae foi aumentado pelo número de Cephalotes sp. (Hymenoptera: Formicidae) e o de A. reticulatum pelo de Brachymyrmex sp. (Hymenoptera: Formicidae) em mudas de A. auriculiformis. O dano de A. reticulatum foi reduzido pelo número de Uspachus sp., mas o dano de Aleyrodidae foi aumentado pelo número de Cephalotes sp., totalizando 23,81% de aumento de danos em mudas de A. auriculiformis. Aqui eu apresento e testo o % I.I.-PD. Ele é um novo índice capaz de detectar fontes de perda e de solução no sistema quando não se conhece a produção final. Ele pode ser aplicado em algumas áreas do conhecimento.


Assuntos
Animais , Formigas , Besouros , Acacia , Hemípteros , Insetos
2.
Protein Expr Purif ; 201: 106174, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36130682

RESUMO

Cysteine peptidases are involved in physiological processes of insect development and have been considered as potential targets for the development of insect control strategies. In this study, we obtained a recombinant cysteine cathepsin L (AsCathL) from leaf-cutting ant (Atta sexdens), a species from the order Hymenoptera who causes enormous damage to crops, natural forests and reforested areas. RT-qPCR showed AsCathL expression throughout insect development and in all body parts of the adult insect analysed, suggesting its role as a lysosomal cathepsin. AsCathL encodes a protein of 320 amino acid residues consisting of a pro-peptide and the mature with amino acids sequence over 67% similarity with lysosomal cathepsin L of species from Lepidoptera and Diptera. Phylogenetic tree revealed that AsCathL is very similar to predicted cathepsins found in other ants. Recombinant AsCathL was expressed in insoluble form by Escherichia coli Arctic Express (DE3) RIL, purified under denaturing conditions and refolded. The enzyme showed hydrolytic activity in vitro towards synthetic substrate Z-Phe-Arg-AMC at acidic pH. Synthetic inhibitor E-64 acted against peptidase activity and a study regarding the interaction between E-64 and AsCathL using nuclear magnetic resonance (NMR) revealed that 83.18% from all E-64 molecules are irreversibly bound to AsCathL. In addition, the proteolytic activity of AsCathL was strongly inhibited by recombinant sugarcane cystatins with Ki ranging from 0.6 nM to 2.95 nM. To the best of our knowledge this is the first report characterizing a cysteine peptidase from leaf-cutting ants, which may contribute to future studies of ants' cathepsins.


Assuntos
Formigas , Cistatinas , Cisteína Proteases , Animais , Formigas/genética , Catepsina L , Cisteína , Cisteína Proteases/genética , Peptídeos , Filogenia
3.
Braz. j. biol ; 83: e245536, 2023. tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1339403

RESUMO

Abstract Acacia mangium (Willd., 1806) (Fabales: Fabaceae) is a fast growing, rustic, pioneer species, with potential to fix nitrogen, and for programs to recover degraded areas. The objective was to evaluate the distribution and the functional diversity of interactions and the K-dominance of arthropod groups on A. mangium saplings. The number of individuals of eleven species of phytophagous insects, three bee species, and fourteen natural enemy species were highest on the adaxial leaf surface of this plant. Abundance, diversity and species richness of phytophagous insects and natural enemies, and abundance and species richness of pollinators were highest on the adaxial A. mangium leaf surface. The distribution of five species of sap-sucking hemipterans and six of protocooperating ants (Hymenoptera), with positive interaction between these groups, and three bee species (Hymenoptera) were aggregated on leaves of A. mangium saplings. Aethalion reticulatum (L.) (Hemiptera: Aethalionidae) and Bemisia sp. (Hemiptera: Aleyrodidae); Brachymyrmex sp. and Camponotus sp. (Hymenoptera: Formicidae); and Trigona spinipes Fabricius (Hymenoptera: Apidae) were the most dominant phytophagous insects, natural enemies, and pollinators, respectively, on A. mangium leaves. Knowledge of preferred leaf surfaces could help integrated pest management programs.


Resumo Acacia mangium (Willd., 1806) (Fabales: Fabaceae) é uma planta pioneira com rápido crescimento, rusticidade, potencial nitrificador e importante em programas de recuperação de áreas degradadas. O objetivo foi avaliar a distribuição e a diversidade funcional das interações e a dominância-K de grupos de artrópodes em árvores jovens de A. mangium. Os números de indivíduos de onze espécies de insetos fitófagos, três de abelhas e quatorze de inimigos naturais foram maiores na superfície adaxial de folhas dessa planta. A abundância, diversidade e riqueza de espécies de insetos fitófagos e inimigos naturais, e a abundância e riqueza de espécies de polinizadores foram maiores na face adaxial de folhas de A. mangium. A distribuição de cinco espécies de hemípteros sugadores de seiva e seis de formigas protocooperantes (Hymenoptera), com interação positiva entre esses grupos, e três de abelhas (Hymenoptera) foi agregada em folhas de plantas jovens de A. mangium. Aethalion reticulatum (L.) (Hemiptera: Aethalionidae) e Bemisia sp. (Hemiptera: Aleyrodidae); Brachymyrmex sp. e Camponotus sp. (Hymenoptera: Formicidae); e Trigona spinipes Fabricius (Hymenoptera: Apidae) foram os insetos fitófagos, inimigos naturais e polinizadores mais dominantes, respectivamente, em folhas de A. mangium. A definição da superfície foliar preferida pode auxiliar programas de manejo integrado de pragas.


Assuntos
Animais , Formigas , Artrópodes , Acacia , Fabaceae , Abelhas , Folhas de Planta
4.
Braz. j. biol ; 83: e243651, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1285608

RESUMO

Abstract 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.


Resumo Acacia auriculiformis A. Cunn. Ex Benth. (Fabaceae), espécie pioneira com rápido crescimento e rusticidade, é utilizada em programas de recuperação de áreas degradadas. O objetivo deste trabalho foi avaliar, durante 24 meses, o padrão de distribuição de artrópodes (insetos fitófagos, abelhas, aranhas e insetos predadores) nas superfícies foliares de A. auriculiformis. Quatorze espécies de fitófagos, duas de abelhas e onze de predadores foram mais abundantes na superfície adaxial. Índices ecológicos (abundância, diversidade e riqueza de espécies) e curvas de rarefação e dominância-k de fitófagos, abelhas e artrópodes predadores foram maiores na face adaxial de folhas de A. auriculiformis. A dominância-k e a abundância de Aleyrodidae (Hemiptera) (ambas as superfícies foliares), da abelha nativa sem ferrão Tetragonisca angustula Latreille (Hymenoptera: Apidae) (ambas as superfícies foliares) e das formigas Brachymyrmex sp. (superfície adaxial) e Pheidole sp. (Hymenoptera: Formicidae) (superfície abaxial) foram as maiores entre os grupos taxonômicos de fitófagos polinizadores e predadores, respectivamente, em plantas jovens de A. auriculiformis. A abundância, diversidade e riqueza e as curvas de rarefação e dominância-k de artrópodes fitófagos, abelhas e predadores foram maiores nas superfícies adaxiais das folhas dessa árvore. A preferência pela superfície adaxial da folha se deve, provavelmente, ao menor esforço para se movimentarem na mesma. Compreender as preferências dos artrópodes pelas superfícies foliares pode auxiliar no desenvolvimento de planos de amostragem e manejo de pragas em A. auriculiformis. Além disso, o conhecimento da distribuição de abelhas e predadores pode favorecer a conservação desses insetos.


Assuntos
Animais , Formigas , Artrópodes , Acacia , Abelhas , Folhas de Planta , Insetos
5.
Braz. j. biol ; 83: e239642, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1278543

RESUMO

Abstract The knowledge of ant assemblages that occurs in Conservation Units in the Atlantic Forest domain is a priority, considering the number of endemic species and the impacts that this biome has been suffering. The aim of this study was to evaluate ant assemblages in the Turvo State Park, which is the largest conservation unit in the State of Rio Grande do Sul and presents an important role on biodiversity protection. Two samplings were conducted in 2019, one in the summer (January) and the other in the spring (November and December), at five sites 2 km apart, with pitfall traps (soil and canopy), sardine baits, glucose, beating net, sweeping net and manual collection. We sampled 121 species in the summer and 120 in the spring, totaling 163 ant species. A total of 78 species (47.8%) occurred in both sampling seasons. The richest genera in the study were Camponotus (S = 30), Pheidole (S = 23) and Linepithema (S = 11). Seventeen species were recorded for the first time for Rio Grande do Sul state. The results indicate that this is one of the most species-rich assemblages of ants ever surveyed in a conservation unit in southern Brazil. The study highlights the importance of Conservation Units as protected environments against habitat loss for ant biodiversity. The results of this study contribute to myrmecofauna knowledge and serve as a basis for environmental impact studies, management plans and conservation of Atlantic Forest remnants.


Resumo O conhecimento das assembleias de formigas que ocorrem em Unidades de Conservação no domínio Mata Atlântica é prioritário, considerando-se o número de espécies endêmicas e os impactos que este bioma vem sofrendo. O objetivo desse trabalho foi caracterizar a assembleia de formigas que ocorre no Parque Estadual do Turvo, a maior unidade de conservação do Rio Grande do Sul que se destaca pelo seu papel na proteção da biodiversidade da Mata Atlântica austral. Foram realizadas duas amostragens no ano de 2019, uma no verão (janeiro) e a outra na primavera (novembro e dezembro), em cinco pontos distantes 2 km entre si, com armadilhas pitfall (solo e dossel), iscas de sardinha, iscas de glicose, guarda-chuva entomológico, rede de varredura e coleta manual. A riqueza amostrada no verão foi de 121 e na primavera de 120, totalizando 163 espécies. Ao todo, 78 espécies (47,8%) ocorreram concomitantemente nas duas amostragens. Os gêneros mais ricos foram Camponotus (S=30), Pheidole (S=23) e Linepithema (S=11). Dezessete espécies foram registradas pela primeira vez para o estado do Rio Grande do Sul. Os resultados se constituem em uma das mais ricas assembleias de formigas já inventariadas em uma unidade de conservação na região sul do Brasil. O estudo destaca a importância das Unidades de Conservação como ambientes protegidos contra a perda de habitat para a biodiversidade de formigas. Os resultados deste estudo contribuem para o conhecimento da mirmecofauna e servem como base para estudos de impacto ambiental, planos de manejo e conservação de remanescentes da Mata Atlântica.


Assuntos
Animais , Formigas , Estações do Ano , Brasil , Ecossistema , Biodiversidade
6.
Braz. j. biol ; 83: e244732, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1278538

RESUMO

Abstract Some studies report the positive effect of organic residues from ant nests on soil properties and on the structure of the adjacent plant community in field experiments, but there is a gap about the effect on individual species. The purpose of the present study was to compare the soil nutrient content and the development of Turnera subulata Smith, an ornamental species, in the presence of the nest refuse (basically composed of fragments of grass leaves and the symbiotic fungus) produced by the leaf-cutting ant Acromyrmex balzani (Emery, 1890) or in control soil through a greenhouse pot experiment. The experiment was carried out with two treatments: control soil and soil with 25% of nest refuse. The plants were kept in 1L pots for 90 days. We evaluated the parameters: plant height, stem diameter, root length, number of leaves, dry weight of the root, dry and fresh aboveground biomass. Additionally, the relative chlorophyll content and leaf nutrients were used as nutritional parameters. As a result, plants that grew in the soil with nest refuse showed significant higher values of all parameters evaluated when compared to the control treatment (p < 0.001). We conclude that this biofertilizer contributed to the production of more vigorous plants, being able to act on the local dynamics of nutrients in the ecosystems where A. balzani occurs. As it is relatively abundant and easy to collect, the refuse of A. balzani has the potential to be used as an alternative substrate in the production of shortlife cycle plants.


Resumo Alguns estudos relatam o efeito positivo de resíduos orgânicos de formigueiros nas propriedades do solo e na estrutura da comunidade de plantas adjacentes em experimentos de campo, mas há uma lacuna sobre o efeito em espécies individuais. O objetivo do presente estudo foi comparar o desenvolvimento de Turnera subulata Smith, uma espécie ornamental, na presença do substrato de descarte (SD) de formigueiros produzido pela formiga cortadeira Acromyrmex balzani (Emery, 1890) por meio de experimento em casa de vegetação. O experimento foi conduzido com dois tratamentos: solo controle e solo com 25% de SD. As plantas foram mantidas em vasos de 1L por 90 dias. Foram avaliados os parâmetros: altura da planta, diâmetro do caule, comprimento da raiz, número de folhas, massa seca da raiz, biomassa seca e fresca da parte aérea. Além disso, o conteúdo relativo de clorofila e os nutrientes foliares foram usados como parâmetros fisiológicos. Como resultado, as plantas que cresceram no solo com SD apresentaram valores significativamente maiores de todos os parâmetros avaliados quando comparadas ao tratamento controle (p < 0.001). Concluímos que esse biofertilizante contribuiu para a produção de plantas mais vigorosas, podendo atuar na dinâmica local de nutrientes nos ecossistemas onde A. balzani ocorre. Além disso, por ser relativamente abundante e fácil de coletar, o SD de A. balzani tem potencial para ser utilizado como biofertilizante na produção de plantas de ciclo de vida curta.


Assuntos
Animais , Formigas , Turnera , Plantas , Solo , Simbiose , Ecossistema , Folhas de Planta
7.
Biochim Biophys Acta Gen Subj ; 1867(1): 130249, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36183893

RESUMO

Chitinases are enzymes that degrade chitin, a polysaccharide found in the exoskeleton of insects, fungi, yeast, and internal structures of other vertebrates. Although chitinases isolated from bacteria, fungi and plants have been reported to have antifungal or insecticide activities, chitinases from insects with these activities have been seldomly reported. In this study, a leaf-cutting ant Atta sexdens DNA fragment containing 1623 base pairs was amplified and cloned into a vector to express the protein (AsChtII-C4B1) in Pichia pastoris. AsChtII-C4B1, which contains one catalytic domain and one carbohydrate-binding module (CBM), was secreted to the extracellular medium and purified by ammonium sulfate precipitation followed by nickel column chromatography. AsChtII-C4B1 showed maximum activity at pH 5.0 and 55 °C when tested against colloidal chitin substrate and maintained >60% of its maximal activity in different temperatures during 48 h. AsChtII-C4B1 decreased the survival of Spodoptera frugiperda larvae fed with an artificial diet that contained AsChtII-C4B1. Our results have indicated that AsChtII-C4B1 has a higher effect on larva-pupa than larva-larva molts. AsChtII-C4B1 activity targets more specifically the growth of filamentous fungus than yeast. This work describes, for the first time, the obtaining a recombinant chitinase from ants and the characterization of its insecticidal and antifungal activities.


Assuntos
Formigas , Quitinases , Animais , Antifúngicos/química , Formigas/enzimologia , Formigas/genética , Formigas/metabolismo , Quitina/química , Quitinases/química , Quitinases/genética , Quitinases/farmacologia , Clonagem Molecular , Fungos/metabolismo , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Saccharomyces cerevisiae/efeitos dos fármacos , Spodoptera/efeitos dos fármacos , Catálise , Domínio Catalítico
8.
Rev. biol. trop ; 70(1)dic. 2022.
Artigo em Inglês | LILACS-Express | LILACS, SaludCR | ID: biblio-1387719

RESUMO

Abstract Introduction: Seed removal by ants is an interaction that may greatly affect the dynamic and structure of the vegetation. This aspect is well known for granivorous ants; however, there is little information on the effect of omnivorous ants. Objective: To assess the potential impact of the omnivorous ant Dorymyrmex insanus on vegetation. Methods: In the Pedregal Reserve, Mexico City, we identified the items in the refuse piles of ten ant colonies, for one year, covering the rainy and dry seasons. For each season we calculated seed diversity and analyzed the possible relationship between seed size and their abundance in the refuse piles, with regression models. We also did germination tests with seeds of Tagetes micrantha, comparing seeds from piles and from plants. Results: D. insanus removed seeds of 19 plant species as well as plant remains (such as leaves, twigs, roots), and remains of insects. Seed diversity was higher in the rainy season but the greatest abundance was in the dry season. When analyzing the relationship between seed length and abundance in the refuse piles, we found that the ants preferred seeds of around 10 mm. We also found that more seeds of T. micrantha germinated when they were previously handled by ants. Conclusions: The ant D. insanus actively participates in the removal of seeds from several species, favoring germination, and seasonality affects the selectivity of resources.


Resumen Introducción: La remoción de semillas por parte de las hormigas es una interacción que puede afectar en gran medida la dinámica y estructura de la vegetación. Este aspecto es bien conocido para las hormigas granívoras; sin embargo, hay poca información sobre el efecto de las omnívoras. Objetivo: Evaluar el impacto potencial de la hormiga omnívora Dorymyrmex insanus sobre la vegetación. Métodos: En la Reserva Pedregal, Ciudad de México, se identificaron los ítems en el área del basurero para diez colonias de hormigas, durante un año, cubriendo la época de lluvia y sequía. Para cada temporada calculamos la diversidad de semillas y analizamos la posible relación entre el tamaño de las semillas y su abundancia en los basureros, con modelos de regresión. También hicimos pruebas de germinación con semillas de Tagetes micrantha, comparando las encontradas en los basureros con las provenientes de las plantas. Resultados: D. insanus eliminó semillas de 19 especies de plantas, así como restos de plantas (hojas, ramitas, raíces) y restos de insectos. La diversidad de semillas fue mayor en la estación lluviosa pero la mayor abundancia lo fue en la estación seca. Al analizar la relación entre la longitud de las semillas y la abundancia en el área del basurero, encontramos que las hormigas preferían semillas de alrededor de 10 mm. También encontramos que germinaron más semillas de T. micrantha cuando fueron manipuladas previamente por hormigas. Conclusiones: La hormiga D. insanus participa activamente en la remoción de semillas de varias especies, favoreciendo la germinación, y la estacionalidad afecta la selectividad de recursos.


Assuntos
Animais , Formigas , Cinturão Ecológico , Dispersão de Sementes , Himenópteros/classificação , México
9.
Sci Rep ; 12(1): 19328, 2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36369461

RESUMO

Ants and other eusocial insects emit and receive chemical signals to communicate important information within the colony. In ants, nestmate recognition, task allocation, and reproductive distribution of labor are largely mediated through the detection of cuticular hydrocarbons (CHCs) that cover the exoskeleton. With their large size and limited volatility, these CHCs are believed to be primarily detected through direct contact with the antennae during behavioral interactions. Here we first use scanning electron microscopy to investigate the unique morphological features of CHC-sensitive basiconic sensilla of two ant species, the black carpenter ant Camponotus pennsylvanicus and the Indian jumping ant Harpegnathos saltator. These basiconic sensilla possess an abundance of small pores typical of most insect olfactory sensilla, but also have a large concave depression at the terminal end. Basiconic sensilla are enriched at the distal segments of the antennae in both species, which aligns with their proposed role in contact chemosensation of CHCs. A survey of these sensilla across additional ant species shows varied microstructures at their tips, but each possess surface textures that would also increase sensory surface area. These unique ant chemosensory sensilla represent yet another example of how specialized structures have evolved to serve the functional requirements of eusocial communication.


Assuntos
Formigas , Animais , Formigas/anatomia & histologia , Sensilas , Hidrocarbonetos , Insetos , Microscopia Eletrônica de Varredura , Antenas de Artrópodes
10.
Proc Biol Sci ; 289(1986): 20221273, 2022 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-36321497

RESUMO

Many social animals display collective activity cycles based on synchronous behavioural oscillations across group members. A classic example is the colony cycle of army ants, where thousands of individuals undergo stereotypical biphasic behavioural cycles of about one month. Cycle phases coincide with brood developmental stages, but the regulation of this cycle is otherwise poorly understood. Here, we probe the regulation of cycle duration through interactions between brood and workers in an experimentally amenable army ant relative, the clonal raider ant. We first establish that cycle length varies across clonal lineages using long-term monitoring data. We then investigate the putative sources and impacts of this variation in a cross-fostering experiment with four lineages combining developmental, morphological and automated behavioural tracking analyses. We show that cycle length variation stems from variation in the duration of the larval developmental stage, and that this stage can be prolonged not only by the clonal lineage of brood (direct genetic effects), but also of the workers (indirect genetic effects). We find similar indirect effects of worker line on brood adult size and, conversely (but more surprisingly), indirect genetic effects of the brood on worker behaviour (walking speed and time spent in the nest).


Assuntos
Formigas , Animais , Formigas/fisiologia , Genótipo , Comportamento Social , Comportamento Animal
11.
Nat Methods ; 19(11): 1324-1325, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36329275

Assuntos
Formigas , Animais
12.
Oecologia ; 200(3-4): 441-454, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36367567

RESUMO

Functional trait-based approaches have provided advances in the understanding of community assembly rules. Broad generalisations remain, however, limited due to the idiosyncratic nature of taxa and ecosystems, especially in tropical regions. We use fine scale resolution (30 m grid) environmental variables and community surveys from nearly 100 secondary tropical forest sites to study niche-based or neutral assembly mechanisms in ground dwelling ants. This provides a unique opportunity for understanding fine scale drivers of taxonomic, functional and phylogenetic diversity in a region characterized by large topographic and climatic differences on a relatively small geographic scale. Precipitation emerged as the most consistent environmental correlate, in shaping taxonomic, phylogenetic and functional aspects of the communities. Functional diversity was weakly associated with topography and temperature related variables. The fourth corner model revealed that femur, scape and mandible length were key traits in response to precipitation, and that communities showed a functional homogenization towards shorter appendages at wetter sites. Our results suggest that neutral and deterministic assembly processes act in concert to shape the taxonomic, phylogenetic and functional aspects of leaf litter ant assemblages. The use of multiple complementary metrics and approaches along environmental gradients are powerful to reveal the subtilities of assembly processes and provide insight into the ways future communities might change.


Assuntos
Formigas , Animais , Ecossistema , Filogenia , Clima , Processos Estocásticos
13.
Nat Commun ; 13(1): 6710, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36344501

RESUMO

Collections of fire ants are a form of active matter, as the ants use their internal metabolism to self-propel. In the absence of aligning interactions, theory and simulations predict that active matter with spatially dependent motility can undergo motility-induced phase separation. However, so far in experiments, the motility effects that drive this process have come from either crowding or an external parameter. Though fire ants are social insects that communicate and cooperate in nontrivial ways, we show that the effect of their interactions can also be understood within the framework of motility-induced phase separation. In this context, the slowing down of ants when they approach each other results in an effective attraction that can lead to space-filling clusters and an eventual formation of dynamical heterogeneities. These results illustrate that motility-induced phase separation can provide a unifying framework to rationalize the behavior of a wide variety of active matter systems.


Assuntos
Formigas , Venenos de Artrópodes , Animais , Interação Social , Aglomeração
14.
Elife ; 112022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36412093

RESUMO

Behavioural economists have identified many psychological manipulations which affect perceived value. A prominent example of this is bundling, in which several small gains (or costs) are experienced as more valuable (or costly) than if the same total amount is presented together. While extensively demonstrated in humans, to our knowledge this effect has never been investigated in an animal, let alone an invertebrate. We trained individual Lasius niger workers to two of three conditions in which either costs (travel distance), gains (sucrose reward), or both were either bundled or segregated: (1) both costs and gains bundled, (2) both segregated, and (3) only gains segregated. We recorded pheromone deposition on the ants' return trips to the nest as measure of perceived value. After training, we offer the ants a binary choice between odours associated with the treatments. While bundling treatment did not affect binary choice, it strongly influenced pheromone deposition. Ants deposited c. 80% more pheromone when rewards were segregated but costs bundled as compared with both costs and rewards being bundled. This pattern is further complicated by the pairwise experience each animal made, and which of the treatments it experiences first during training. This demonstrates that even insects are influenced by bundling effects. We propose that the deviation between binary choice and pheromone deposition in this case may be due to a possible linearity in distance perception in ants, while almost all other sensory perception in animals is logarithmic.


Assuntos
Formigas , Animais , Humanos , Feromônios , Recompensa , Odorantes , Sacarose
15.
Molecules ; 27(20)2022 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-36296645

RESUMO

In our natural product screening program, we screened natural products for their repellency and toxicity against insect vectors. Methanolic extract of aerial parts of Stenaria nigricans (Lam.), with no published chemistry, was tested for repellency against mosquitoes and imported hybrid fire ants. Methanolic extracts showed biting deterrence similar to DEET (N,N-diethyl-3-methylbenzamide) against Aedes aegypti L. Based on this activity, the crude extract was fractionated into chloroform, ethyl acetate, and methanol subfractions. The active methanolic subfraction was further fractionated into 13 subfractions. These fractions were tested for their biting deterrence against Ae. Aegypti. Active subfractions were further characterized to identify the compounds responsible for this activity. Four undescribed iridoid glucosides (1-4) and three previously reported compounds (5-7) were isolated from active subfractions and tested for their biting deterrent activity. Based on BDI values, compounds 2, 3, 6, and 7, with biting deterrence similar to DEET, showed the potential to be used as repellents against mosquitoes. In an in vitro digging bioassay, none of these compounds showed any repellency against hybrid imported fire ants at a dose of 125 µg/g. This is the first report of biting deterrence and repellency of S. nigricans extract and its pure compounds, iridoid glucosides against mosquitoes and imported fire ants. Further studies will be conducted to explore the repellent potential of these compounds in different formulations under field conditions.


Assuntos
Aedes , Formigas , Produtos Biológicos , Culicidae , Repelentes de Insetos , Rubiaceae , Animais , DEET , Glucosídeos Iridoides , Metanol , Clorofórmio , Mosquitos Vetores , Repelentes de Insetos/farmacologia , Bioensaio , Misturas Complexas
17.
Proc Natl Acad Sci U S A ; 119(42): e2214825119, 2022 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-36197959
18.
Gigascience ; 112022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36305606

RESUMO

BACKGROUND: The motion and interaction of social insects (such as ants) have been studied by many researchers to understand clustering mechanisms. Most studies in the field of ant behavior have focused only on indoor environments (a laboratory setup), while outdoor environments (natural environments) are still underexplored. FINDINGS: In this article, we collect 10 videos of 3 species of ant colonies from different scenes, including 5 indoor and 5 outdoor scenes. We develop an image sequence marking software named VisualMarkData, which enables us to provide annotations of the ants in the videos. (i) It offers comprehensive annotations of states at the individual-target and colony-target levels. (ii) It provides a simple matrix format to represent multiple targets and multiple groups of annotations (along with their IDs and behavior labels). (iii) During the annotation process, we propose a simple and effective visualization that takes the annotation information of the previous frame as a reference, and then a user can simply click on the center point of each target to complete the annotation task. (iv) We develop a user-friendly window-based GUI to minimize labor and maximize annotation quality. In all 5,354 frames, the location information and the identification number of each ant are recorded for a total of 712 ants and 114,112 annotations. Moreover, we provide visual analysis tools to assess and validate the technical quality and reproducibility of our data. CONCLUSIONS: We provide a large-scale ant dataset with the accompanying annotation software. It is hoped that our work will contribute to a deeper exploration of the behavior of ant colonies.


Assuntos
Formigas , Animais , Reprodutibilidade dos Testes , Análise por Conglomerados , Software
19.
Viruses ; 14(10)2022 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-36298716

RESUMO

The yellow crazy ant, Anoplolepis gracilipes is a widespread invasive ant that poses significant threats to local biodiversity. Yet, compared to other global invasive ant species such as the red imported fire ant (Solenopsis invicta) or the Argentine ant (Linepithema humile), little is known about the diversity of RNA viruses in the yellow crazy ant. In the current study, we generated a transcriptomic database for A. gracilipes using a high throughput sequencing approach to identify new RNA viruses and characterize their genomes. Four virus species assigned to Dicistroviridae, two to Iflaviridae, one to Polycipiviridae, and two unclassified Riboviria viruses were identified. Detailed genomic characterization was carried out on the polycipivirus and revealed that this virus comprises 11,644 nucleotides with six open reading frames. Phylogenetic analysis and pairwise amino acid identity comparison classified this virus into the genus Sopolycivirus under Polycipiviridae, which is tentatively named "Anoplolepis gracilipes virus 3 (AgrV-3)". Evolutionary analysis showed that AgrV-3 possesses a high level of genetic diversity and elevated mutation rate, combined with the common presence of multiple viral strains within single worker individuals, suggesting AgrV-3 likely evolves following the quasispecies model. A subsequent field survey placed the viral pathogen "hotspot" of A. gracilipes in the Southeast Asian region, a pattern consistent with the region being recognized as part of the ant's native range. Lastly, infection of multiple virus species seems prevalent across field colonies and may have been linked to the ant's social organization.


Assuntos
Formigas , Vírus de RNA , Humanos , Animais , Filogenia , Vírus de RNA/genética , Espécies Introduzidas , Aminoácidos/genética , Nucleotídeos
20.
Arthropod Struct Dev ; 71: 101212, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36270167

RESUMO

The prepharyngeal gland (prePG) and pharyngeal gland (PG) make up the largest exocrine structures in the head of the ant Camponotus japonicus. We used microscopy to study the histological and ultrastructural features of both glands in different castes. The number of secretory units in the prePG is considerably higher than in other ant species and shows a complex duct system which is made up by duct cells, secondary ducts and a main duct. These lead the secretions of hundreds to thousands of secretory cells into the prepharynx through a modified sieve plate at each side. The glove-shaped PG shows clear caste differences in tubule number. The ultrastructure of both the prePG and PG shows abundant mitochondria and secretion vesicles. Moreover, the prePG is loaded with rough endoplasmic reticulum (RER) which means its main secretions are proteinaceous compounds, while the PG is dominated by smooth endoplasmic reticulum (SER) which means the main secretions are lipids. The morphological differences like cell number of the prePG and tubule number of the PG indicate different secretory abilities of each caste. We for the first time introduce histology-based relative size to indicate secretory activity. The proportionally high development of the prePG in minor workers supports a role in trophallaxis.


Assuntos
Formigas , Animais , Formigas/anatomia & histologia , Microscopia , Glândulas Exócrinas/ultraestrutura
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