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Terezinha Maria Castro Della Lucia - One of the best experts on this subject based on the ideXlab platform.
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Age Polyethism in Atta sexdens (Linnaeus) (Hymenoptera: Formicidae)
Sociobiology, 2020Co-Authors: Fabrícia Gonçalves Lacerda, Terezinha Maria Castro Della Lucia, Leandro Sousa-souto, Danival José De SouzaAbstract:This study aimed to verify age polyethism occurrence in medium-sized (cephalic capsule = 2.3 ± 0.21 mm) and small-sized (cc = 1.4 ± 0.10 mm) workers from Atta sexdens (Linnaeus) colonies. Four laboratory colonies were used, and they were maintained at 25 ± 2 °C, with 75 ± 3% relative humidity and a 12-hour photoperiod. Workers from these colonies were marked after their emergence and observed throughout their lifetime to determine which tasks they performed. The number of ants performing each activity was analyzed using linear mixed-effect models (LME), considering the temporal effect and the block design (colonies). We found that fungal garden maintenance tasks were frequent for both sizes, but their occurrence decreased significantly from the ninth week. The foraging activity occurred gradually in both sizes, with stabilization in the number of workers from the fourth week onwards and declined in the last three weeks of lifespan. Waste management tasks occurred throughout life but were more frequent during the first two weeks of life, in both medium and small workers. Therefore, age polyethism may be related to all activities; however, foraging tasks presented a distinct pattern compared to tasks in the fungus garden and refuse dump, where younger ants were more frequently observed.
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interference of β eudesmol in nestmate recognition in Atta sexdens rubropilosa hymenoptera formicidae
Bulletin of Entomological Research, 2008Co-Authors: Cidália Gabriela Santos Marinho, Myriam M. R. Ribeiro, S.t.v. Magalhães, Raul Nc Guedes, Terezinha Maria Castro Della Lucia, Gulab Newandram JhamAbstract:Leaf-cutter ant species (Atta spp.) are key pests of cultivated crops in the Neotropics, and recent studies have demonstrated that workers of Atta spp., particularly of Atta sexdens rubropilosa, exhibit aggressive behavior among nestmates when in contact with the sesquiterpene β-eudesmol, found in leaves of Eucalyptus maculata. However, the underlying mechanism sparking this behavior pattern has yet to be investigated. This work aimed to elucidate the mechanism by which this substance elicits aggression in workers of A. sexdens rubropilosa. The results, thus obtained, showed that β-eudesmol is able to modify the chemical composition of the workers cuticle, impairing nestmate recognition, triggering alarm behavior and leading to nestmate aggression.
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Parasitismo por Neodohrniphora spp. Malloch (Diptera, Phoridae) em operárias de Atta sexdens rubropilosa Forel (Hymenoptera, Formicidae) Parasitism by Neodohrniphora spp. Malloch (Diptera, Phoridae) on workers of Atta sexdens rubropilosa Forel (Hymenoptera, Formicidae)
Elsevier, 2008Co-Authors: Marcos A. L. Bragança, Lucas Machado De Souza, Carlos André Nogueira, Terezinha Maria Castro Della LuciaAbstract:Parasitóides do gênero Neodohrniphora Malloch, 1914 geralmente atacam operárias de Atta sexdens rubropilosa Forel, 1908 em baixa freqüência, mas os ataques alteram o ritmo de forrageamento das colônias, reduzindo o número e tamanho das operárias e aumentando o abandono de fragmentos vegetais ao longo das trilhas. O forrageamento de A. sexdens rubropilosa pode ser diurno ou noturno, mas existem dúvidas se Neodohrniphora spp. atacam as operárias dessa formiga também durante a noite. Os objetivos deste estudo foram verificar a ocorrência de ataques e avaliar o grau de parasitismo de forídeos do gênero Neodohrniphora em operárias de A. sexdens rubropilosa sob três níveis de luminosidade em laboratório, incluindo a ausência de luz. Os níveis de luminosidade foram: alta (0,65 µmol/m³/s); baixa (0,05 µmol/m³/s) e ausência de luz (0,0 µmol/m³/s). Fêmeas de Neodohrniphora tonhascai Brown, 2001 e Neodohrniphora elongata Brown, 2001 coletadas no campo e liberadas em laboratório somente efetuaram ataques e foram obtidas operárias parasitadas sob alta luminosidade, sugerindo que essas espécies não são ativas no campo durante o período noturno (ausência de luz). Os resultados sugerem também que o estímulo visual em Neodohrniphora spp. pode ser um componente essencial para a localização e reconhecimento do hospedeiro.Parasitoids of the genus Neodohrniphora Malloch, 1914 generally Attack workers of Atta sexdens rubropilosa Forel, 1908 in low ratios. However these Attacks alter the foraging rhythm and reduces the number and size of workers as well as increases the number of abandoned plant fragments along the trails. A. sexdens rubropilosa can have a diurnal or nocturnal foraging activity, but it is uncertain if Neodohrniphora spp. Attacks workers of this host during the night. The objective of this work was to verify the occurrence of Neodohrniphora phorids Attacks and the level of parasitism on workers of A. sexdens rubropilosa under three light levels in laboratory, including the darkness. The levels of illumination were: high-light (0.65 µmol/m³/s); low-light (0.05 µmol/m³/s) and darkness (0.0 µmol/m³/s). Field collected parasitoid females (Neodohrniphora tonhascai Brown, 2001 and Neodohrniphora elongate Brown, 2001) released in laboratory have Attacked and parasitized A. sexdens rubropilosa workers only under high-light level. This suggests that these two Neodohrniphora species are not active in the field during the night (darkness) and that visual stimulus could be an essential component to the location and recognition of the host
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first record of phorid parasitoids diptera phoridae of the leaf cutting ant Atta bisphaerica forel hymenoptera formicidae
Neotropical Entomology, 2003Co-Authors: Marcos A. L. Bragança, Terezinha Maria Castro Della Lucia, Athayde TonhascaAbstract:Phoridae flies parasitize several ant species, including many Atta leaf-cutting ants. In this note, the Attacks of three coexisting phorid species (Myrmosicarius grandicornis Borgmeier, Apocephalus attophilus Borgmeier and Neodorhniphora bragancai Brown) against Atta bisphaerica Forel workers in a pasture located in Vicosa County, Minas Gerais State, Brazil, are reported. The first two species of phorids are known to parasitize other leaf-cutting ants. N. bragancai, however, has been found only around A. bisphaerica nests. Each of these phorid species selects ants engaged in different tasks and oviposits in specific sites of the ant body.
David J Stradling - One of the best experts on this subject based on the ideXlab platform.
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traffic dynamics of the leaf cutting ant Atta cephalotes
The American Naturalist, 2002Co-Authors: Martin Burd, Debbie Archer, Nuvan Aranwela, David J StradlingAbstract:Abstract: Colonies of Atta cephalotes (Myrmicinae: Formicidae) construct cleared paths between their nest and the vegetation sources at which they harvest leaf tissue. Here, we employ ideas from traffic engineering to study streams of laden and unladen ants on these paths. The relationship between average traffic speed and the concentration of workers on the road surface follows a relationship similar to what is expected by analogy to fluid dynamics. Although the traffic is composed of eusocial organisms with a common interest in group success, the coarse‐grained behavior of Atta traffic displays little more coordination than a moving fluid. The relationship between speed and concentration implies that maximum flow rates (which are likely to be closely tied to colony‐level rates of resource acquisition) occur at a relatively high concentration that keeps individual speeds well below their “free flow” maximum. We predict that this optimal concentration will characterize peak traffic throughout a trail netw...
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chemistry of metapleural gland secretions of three attine ants Atta sexdens rubropilosa Atta cephalotes and acromyrmex octospinosus hymenoptera formicidae
Journal of Chemical Ecology, 1996Co-Authors: Ruth Do R Nascimento, Eric Schoeters, David E Morgan, Johan Billen, David J StradlingAbstract:The chemical composition of the secretions of the metapleural glands of workers and soldiers of twoAtta species,Atta sexdens rubropilosa andA. cephalotes, and workers ofAcromyrmex octospinosus, has been studied. As indicated by infrared spectrometry and confirmed by the ninhydrin test, the secretions contain chiefly proteins. Of the volatile acidic portion, which is present as ionized salts, phenylacetic acid is the major component in workers and soldiers ofA. s. rubropilosa andA. cephalotes. BothAtta species also contain 3-hydroxydecanoic acid and its homolog as minor components together with indoleacetic acid. While there are qualitative similarities in the acidic composition in the secretions ofA. s. rubropilosa andA. cephalotes, they differ quantitatively. The secretion ofAcromyrmex octospinosus contains 3-hydroxydecanoic and indoleacetic acids, but lacks phenylacetic acid. The bactericidal and fungicidal actions of the three major substances have been confirmed.
Gulab Newandram Jham - One of the best experts on this subject based on the ideXlab platform.
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interference of β eudesmol in nestmate recognition in Atta sexdens rubropilosa hymenoptera formicidae
Bulletin of Entomological Research, 2008Co-Authors: Cidália Gabriela Santos Marinho, Myriam M. R. Ribeiro, S.t.v. Magalhães, Raul Nc Guedes, Terezinha Maria Castro Della Lucia, Gulab Newandram JhamAbstract:Leaf-cutter ant species (Atta spp.) are key pests of cultivated crops in the Neotropics, and recent studies have demonstrated that workers of Atta spp., particularly of Atta sexdens rubropilosa, exhibit aggressive behavior among nestmates when in contact with the sesquiterpene β-eudesmol, found in leaves of Eucalyptus maculata. However, the underlying mechanism sparking this behavior pattern has yet to be investigated. This work aimed to elucidate the mechanism by which this substance elicits aggression in workers of A. sexdens rubropilosa. The results, thus obtained, showed that β-eudesmol is able to modify the chemical composition of the workers cuticle, impairing nestmate recognition, triggering alarm behavior and leading to nestmate aggression.
Peter Mueller - One of the best experts on this subject based on the ideXlab platform.
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atom trap trace analysis of rare noble gas isotopes
Advances in Atomic Molecular and Optical Physics, 2010Co-Authors: Peter MuellerAbstract:Abstract Ultrasensitive analysis of long-lived rare isotopes is performed in a broad range of scientific and technological fields. Based on the technologies of laser trapping and cooling, Atom Trap Trace Analysis (Atta) is a method capable of analyzing trace isotopes with an isotopic abundance at and below the parts-per-trillion (10 −12 ) level. Atta has enabled us to measure radiokrypton isotopes 81 Kr (half-life = 229,000 yr, atmospheric isotopic abundance =1×10 −12 ) and 85 Kr (10.8 yr, 10 −11 ) in environmental samples. The cosmogenic 81 Kr is the ideal tracer for dating water and ice in the age range of 10 5 -10 6 years, a range beyond the reach of radiocarbon dating. Using the current generation instrument (Atta-2), 81 Kr-dating was performed to determine the ages of the old groundwater in the Nubian Aquifer located underneath the Sahara Desert. However, due to the low trap loading efficiency of 10 −4 , a sample of >1000 liters of water was required for each groundwater measurement, making the method cumbersome for routine scientific applications. Recent developments in our laboratory have made it possible to further improve both the counting rate and counting efficiency of the Atta method. The more advanced Atta instruments currently under development are expected to find applications in environmental science, earth science, nuclear waste management, nuclear non-proliferation, as well as basic research in nuclear and particle physics. Future development in pulsed VUV lasers may push the Atta technique further towards perfection.
Reika Yokochi - One of the best experts on this subject based on the ideXlab platform.
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tracer applications of noble gas radionuclides in the geosciences
Earth-Science Reviews, 2014Co-Authors: Peter Schlosser, B.m. Kennedy, William M Smethie, Neil C Sturchio, T P Fischer, R Purtschert, Jeffrey P Severinghaus, D K Solomon, Toste Tanhua, Reika YokochiAbstract:Noble gas radionuclides, including 81Kr (t1/2 = 229,000 years), 85Kr (t1/2 = 10.8 years), and 39Ar (t1/2 = 269 years), possess nearly ideal chemical and physical properties for studies of earth and environmental processes. Recent advances in Atom Trap Trace Analysis (Atta), a laser-based atom counting method, have enabled routine measurements of the radiokrypton isotopes, as well as the demonstration of the ability to measure 39Ar in environmental samples. Here we provide an overview of the Atta technique, and a survey of recent progress made in several laboratories worldwide. We review the application of noble gas radionuclides in the geosciences and discuss how Atta can help advance these fields, specifically: determination of groundwater residence times using 81Kr, 85Kr, and 39Ar; dating old glacial ice using 81Kr; and an 39Ar survey of the main water masses of the oceans, to study circulation pathways and estimate mean residence times. Other scientific questions involving a deeper circulation of fluids in the Earth's crust and mantle are also within the scope of future applications. We conclude that the geoscience community would greatly benefit from an Atta facility dedicated to this field, with instrumentation for routine measurements, as well as for research on further development of Atta methods.
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tracer applications of noble gas radionuclides in the geosciences
arXiv: Geophysics, 2013Co-Authors: Peter Schlosser, B.m. Kennedy, William M Smethie, Neil C Sturchio, T P Fischer, R Purtschert, Jeffrey P Severinghaus, D K Solomon, Toste Tanhua, Reika YokochiAbstract:The noble gas radionuclides, including 81Kr (half-life = 229,000 yr), 85Kr (11 yr), and 39Ar (269 yr), possess nearly ideal chemical and physical properties for studies of earth and environmental processes. Recent advances in Atom Trap Trace Analysis (Atta), a laser-based atom counting method, have enabled routine measurements of the radiokrypton isotopes, as well as the demonstration of the ability to measure 39Ar in environmental samples. Here we provide an overview of the Atta technique, and a survey of recent progress made in several laboratories worldwide. We review the application of noble gas radionuclides in the geosciences and discuss how Atta can help advance these fields, specifically determination of groundwater residence times using 81Kr, 85Kr, and 39Ar; dating old glacial ice using 81Kr; and an 39Ar survey of the main water masses of the oceans, to study circulation pathways and estimate mean residence times. Other scientific questions involving deeper circulation of fluids in the Earth's crust and mantle also are within the scope of future applications. We conclude that the geoscience community would greatly benefit from an Atta facility dedicated to this field, with instrumentation for routine measurements, as well as for research on further development of Atta methods.
