Feeding behavior and social interactions of the Argentine ant Linepithema humile change with sucrose concentration.

Liquid sugar baits are well accepted by the Argentine ant Linepithema humile and are suitable for the chemical control of this invasive species. We evaluated how sugar concentrations affect the foraging behavior of L. humile individuals. We quantified feeding variables for individual foragers (ingested load, feeding time and solution intake rate) when feeding on sucrose solutions of different concentrations, as well as post-feeding interactions with nestmates. Solutions of intermediate sucrose concentrations (10-30%) were the most consumed and had the highest intake rates, whereas solutions of high sucrose concentrations (60 and 70%) resulted in extended feeding times, low intake rates and ants having smaller crop loads. In terms of post-feeding interactions, individuals fed solutions of intermediate sucrose concentrations (20%) had the highest probability of conducting trophallaxis and the smallest latency to drop exposure (i.e. lowest time delay). Trophallaxis duration increased with increasing sucrose concentrations. Behavioral motor displays, including contacts with head jerking and walking with a gaster waggle, were lowest for individuals that ingested the more dilute sucrose solution (5%). These behaviors have been previously suggested to act as a communication channel for the activation and/or recruitment of nestmates. We show here that sucrose concentration affects feeding dynamics and modulates decision making related to individual behavior and social interactions of foragers. Our results indicate that intermediate sucrose concentrations (ca. 20%), appear to be most appropriate for toxic baits because they promote rapid foraging cycles, a high crop load per individual, and a high degree of stimulation for recruitment.

A glimpse at Ethology in Latin America

The state of the art of Ethology in five Latin America countries is briefly presented here. The overall outlook regarding research laboratories and themes is promising: the community is numerous, active and there are topics addressing all aspects of animal behavior, especially in large countries like Brazil and Argentina. Ethology as an undergraduate discipline is generally a sub-category of Biology, being taught mainly at Zoology/ Psychology/ Ecology/ Agriculture Courses and at Medical Veterinary Schools, often as an eligible discipline. Ethology as a formal major Graduate Program is rare and mainly restricted to Brazil. Regular Ethology meetings are held in Argentina, Brazil and Uruguay. In Chile and Venezuela there is a small but very active community. Studies of animal behavior are often carried out in other areas than Biology, and there is a clear overlap of interest regarding the major topics of Ethology. Behavioral ecology, conservation, management and animal welfare are a priority in most countries, probably reflecting a general concern regarding endangered species and habitats of the continent. Here we present information aiming to create a network that will increase collaborations among researchers working within the ethological framework in Latin America. The IV Simpósio de Etologia na América Latina, entitled "Desarrollo de la Etología en Latinoamérica:¿ hacia un futuro regional ?" was held in November, 2013, as part of the XXXI Encontro Anual de Etologia (EAE), in São Paulo, SP, Brazil. The state of art of Animal Behavior in Argentina, Brazil, Chile, Uruguay and Venezuela were presented there and a set of six questions guided the presentations: 1) What are the main Ethology topics being studied in laboratories in your country? - 2) Are there undergraduate or graduate programs in the main universities? - 3) Is there an Animal Behavior Society? How interested is the community in establishing close ties among institutes or laboratories elsewhere in Latin America? - 4) Is there a site, a journal, a page on a social networking site for contact, communication and divulgation of original data? - 5) How active is the community regarding the wiliness to organize congresses, symposia, meetings, workshops, on-line courses regarding Ethology? - 6) Are there funding agencies to support exchange programs and research in Ethology? Additional data were collected from the last two EAE regarding researchers from Latin America that attended EAE meetings and a list of names and laboratories was compiled (see appendix). It should be emphasized that the compilation of information presented here is far from complete. It represents a brief overview of the current status of Ethology in only five Latin American countries, and therefore it should be updated continuously with new data from the countries treated here as well as supplemented with data from other countries. Such a constantly updated list would facilitate the creation of networks that should increase collaborations among researchers working within the ethological framework in Latin America.(AU)

Presentamos brevemente el estado de la Etología en cinco países de América Latina. En general, con respecto a la investigación en laboratorios y temas de estudio la situación es prometedora: la comunidad es numerosa, activa, y los temas abarcan todos los aspectos del comportamiento animal, especialmente en países grandes como Brasil y Argentina. La Etología como disciplina de grado, por lo general es una subcategoría de la Biología, siendo impartida principalmente en cursos de Zoología /Psicología/ Ecología/Agricultura, y en las facultades de Medicina Veterinaria frecuentemente como disciplina opcional. No es frecuente que la Etología sea un programa formal de Posgrado, lo cual está principalmente restringido a Brasil. Se realizan encuentros regulares de Etología en Argentina, Brasil y Uruguay. En Chile y Venezuela se encuentran comunidades pequeñas pero muy activas, ligadas a la Etología. Los estudios de comportamiento animal se realizan frecuentemente en áreas distintas de la Biología, y hay una clara superposición de intereses respecto a los principales tópicos de la Etología. La ecología comportamental, la conservación, el manejo y el bienestar animal son prioridades en muchos países, lo que probablemente refleja una preocupación general respecto a las especies y hábitats amenazados en el continente. Aquí presentamos un informe preliminar orientado a crear una red que aumente la colaboración entre los investigadores que trabajan en el marco de la Etología en América Latina. El IV Simposio de Etología de América Latina, titulado "Desarrollo de la Etología en Latinoamérica:¿hacia un futuro regional?" se realizó en Noviembre de 2013, como parte del XXXI Encontro Anual de Etologia (EAE), en São Paulo, SP, Brasil. Invitados de cinco países -Argentina, Brasil, Chile, Uruguay y Venezuela- presentaron información sobre el estado del arte del comportamiento animal en sus naciones y las presentaciones fueron guiadas por un cuestionario de seis preguntas: 1) ¿Cuáles son los principales temas de estudio y laboratorios de Etología en su país? - 2) ¿Hay programas de grado o posgrado en las principales universidades? - 3) ¿Hay una sociedad de Comportamiento Animal? ¿Qué tan interesada está la comunidad en establecer vínculos estrechos entre institutos o laboratorios en otros lugares de América Latina? - 4) ¿Hay un sitio de internet, una revista o un en una red social para contacto, comunicación y divulgación de datos originales? - 5) ¿Qué tan activa es la comunidad respecto a la organización de congresos, simposios, encuentros, talleres y cursos on-line referidos a Etología? - 6) ¿Hay agencias de financiamiento para sostener programas de intercambio e investigación en Etología? Adicionalmente se recolectaron datos de los últimos dos EAE concerniente a los investigadores en América Latina que asistieron a los mismos y se compiló una lista de nombres y laboratorios.(AU)

A glimpse at ethology in latin america

The state of the art of Ethology in five Latin America countries is briefly presented here. The overall outlook regarding research laboratories and themes is promising: the community is numerous, active and there are topics addressing all aspects of animal behavior, especially in large countries like Brazil and Argentina. Ethology as an undergraduate discipline is generally a sub-category of Biology, being taught mainly at Zoology/ Psychology/ Ecology/ Agriculture Courses and at Medical Veterinary Schools, often as an eligible discipline. Ethology as a formal major Graduate Program is rare and mainly restricted to Brazil. Regular Ethology meetings are held in Argentina, Brazil and Uruguay. In Chile and Venezuela there is a small but very active community. Studies of animal behavior are often carried out in other areas than Biology, and there is a clear overlap of interest regarding the major topics of Ethology. Behavioral ecology, conservation, management and animal welfare are a priority in most countries, probably reflecting a general concern regarding endangered species and habitats of the continent. Here we present information aiming to create a network that will increase collaborations among researchers working within the ethological framework in Latin America. The IV Simpósio de Etologia na América Latina, entitled "Desarrollo de la Etología en Latinoamérica:¿ hacia un futuro regional ?" was held in November, 2013, as part of the XXXI Encontro Anual de Etologia (EAE), in São Paulo, SP, Brazil. The state of art of Animal Behavior in Argentina, Brazil, Chile, Uruguay and Venezuela were presented there and a set of six questions guided the presentations: 1).

Presentamos brevemente el estado de la Etología en cinco países de América Latina. En general, con respecto a la investigación en laboratorios y temas de estudio la situación es prometedora: la comunidad es numerosa, activa, y los temas abarcan todos los aspectos del comportamiento animal, especialmente en países grandes como Brasil y Argentina. La Etología como disciplina de grado, por lo general es una subcategoría de la Biología, siendo impartida principalmente en cursos de Zoología /Psicología/ Ecología/Agricultura, y en las facultades de Medicina Veterinaria frecuentemente como disciplina opcional. No es frecuente que la Etología sea un programa formal de Posgrado, lo cual está principalmente restringido a Brasil. Se realizan encuentros regulares de Etología en Argentina, Brasil y Uruguay. En Chile y Venezuela se encuentran comunidades pequeñas pero muy activas, ligadas a la Etología. Los estudios de comportamiento animal se realizan frecuentemente en áreas distintas de la Biología, y hay una clara superposición de intereses respecto a los principales tópicos de la Etología. La ecología comportamental, la conservación, el manejo y el bienestar animal son prioridades en muchos países, lo que probablemente refleja una preocupación general respecto a las especies y hábitats amenazados en el continente. Aquí presentamos un informe preliminar orientado a crear una red que aumente la colaboración entre los investigadores que trabajan en el marco de la Etología en América Latina. El IV Simposio de Etología de América Latina, titulado "Desarrollo de la Etología en Latinoamérica:¿hacia un futuro regional?" se realizó en Noviembre de 2013, como parte del XXXI Encontro Anual de Etologia (EAE), en São Paulo, SP, Brasil. Invitados de cinco países -Argentina, Brasil, Chile, Uruguay y Venezuela- presentaron información sobre el estado del arte del comportamiento animal en sus naciones y las presentaciones fueron guiadas por un cuestionario de seis preguntas: 1) .

Nectar feeding by the hovering hawk moth Macroglossum stellatarum: intake rate as a function of viscosity and concentration of sucrose solutions.

Although nectar feeding in insects has long been studied, the knowledge of the effect of nectar energy content on the ingestion dynamics separately from the viscosity of the fluid is very limited. To determine the effects of both factors on the feeding behavior of the hovering hawk moth Macroglossum stellatarum, we developed a method to independently manipulate sucrose concentrations and viscosity. The intake rate was analyzed as a function of sucrose concentration, the concentration at constant viscosity (kept constant by adding tylose, an inert polysaccharide), and of the different viscosities of a 30% weight/weight (w/w) sucrose solution (by adding different amounts of tylose). By increasing the concentration, and thus its viscosity, the solution intake rate (in microl s (-1)) decreased beyond a 20% w/w sucrose solution. For a 30% sucrose solution, the intake rate decreased with increasing viscosity. At constant viscosity, the solution intake rate decreased beyond a 30% w/w sucrose solution. However, if we considered the quantity of sucrose ingested per unit time (sucrose intake rate), the same fitted maximum was attained for both series in which the sucrose concentration changed (33.6% w/w). Results suggest that the gustatory input affects the dynamics of fluid ingestion separately from the viscosity.

Nectar feeding by the ant Camponotus mus: intake rate and crop filling as a function of sucrose concentration.

In independent assays, workers of the ant Camponotus mus were conditioned to visit an arena where they found a large drop of sucrose solution of different concentrations, from 5 to 70% weight on weight (w/w). Single ants were allowed to collect the sucrose solution ad libitum, and feeding time, feeding interruptions, crop load, and intake rates were recorded. Feeding time increased exponentially with sucrose concentration, and this relationship was quantitatively described by the increase in viscosity with concentration corresponding to pure sucrose solutions. Ants collecting dilute solutions (5 to 15% w/w) returned to the nest with partial crop loads. Crop filling increased with increasing sucrose concentration, and reached a maximum at 42.6% w/w. Workers collecting highly concentrated solutions (70% w/w) also returned to the nest with a partially-filled crop, as observed for dilute solutions. Nectar intake rate was observed to increase with increasing sucrose concentration in the range 5 to 30% sucrose. It reached a maximum at 30.8%, and declined with increasing sucrose concentration. Results suggest that both sucrose concentration and viscosity of the ingested solution modulate feeding mechanics as well as the worker's decision about the load size to be collected before leaving the source.