Seasonal activity of Dinoponera quadriceps Santschi (Formicidae, Ponerinae) in the semi-arid Caatinga of northeastern Brazil

Abstract

ABSTRACT. Seasonal activity of Dinoponera quadriceps Santschi (Formicidae, Ponerinae) in the semi-arid Caatinga of northeastern Brazil. We studied seasonal foraging patterns of the queenless ant D. quadriceps (Formicidae, Ponerinae) for 24 months in a Caatinga area of northeastern Brazil, an ecosystem characterized by strong climatic changes throughout the year, in order to determine if regulation of worker activity is based on environmental conditions (air temperature, relative humidity, precipitation) and/or food resources (potential prey: Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, Orthoptera, Araneae, Chilopoda and Diplopoda). Foraging activity of D. quadriceps varied over the course of both years, with the highest frequency occurring from May to August, corresponding to the late rainy season and early dry season. This foraging activity was negatively correlated with temperature and positively correlated with the availability of potential prey, but not with total abundance of soil arthropods or with rainfall and relative humidity. Diet composition, in relation to the main taxonomic prey groups, seems to be common to the species, regardless of habitat. Our results suggest that D. quadriceps workers adjust foraging activity to the most suitable period of the year, to avoid thermal stress and increase efficiency. Thus, they present an appropriate behavioral response to seasonal fluctuations in the Caatinga.KEYWORDS. Ants; environmental factors; foraging; Neotropical region, seasonality.RESUMO. Atividade sazonal de Dinoponera quadriceps Santschi (Formicidae, Ponerinae) em caatinga semiárida do nordeste brasileiro. Foi estudado o padrão de forrageamento da formiga sem rainha D. quadriceps (Formicidae, Ponerinae) durante 24 meses em uma área de caatinga do nordeste brasileiro, um ecossistema caracterizado pelas fortes mudanças climáticas ao longo do ano, com objetivo de determinar se a atividade das operárias é regulada pelas condições ambientais (temperatura do ar, umidade relativa, precipitação) e/ou recursos alimentares (presas potenciais: Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, Orthoptera, Araneae, Chilopoda e Diplopoda). A atividade de forrageamento de D. quadriceps variou ao longo dos dois anos, com a maior freqüência ocorrendo de maio a agosto, correspondendo ao final da estação chuvosa e início da estação seca. Essa atividade de forrageamento foi negativamente relacionada com a temperatura e positivamente relacionada com a disponibilidade de presas potenciais. Não houve relação com a abundância total de artrópodes de solo, precipitação e umidade relativa. A composição da dieta, em relação aos grupos taxonômicos das presas, parece ser comum à espécie, independente do habitat. Os resultados sugerem que as operárias de D. quadriceps ajustam sua atividade de forrageamento ao longo do ano para evitar estresse térmico e aumentar sua eficiência. Desta forma, elas possuem uma resposta comportamental apropriada para a flutuação sazonal da Caatinga.

A revision of the giant Amazonian ants of the genus Dinoponera (Hymenoptera, Formicidae)

“…Dinoponera quadriceps has a marked seasonal pattern in activity. It is most active in May-August , the late rainy season to early dry season in the semiarid Caatinga (Medeiros et al 2012). Activity was strongly negatively correlated to temperature and positively correlated to prey abundance (Medeiros et al 2012).…”

“…It is most active in May-August , the late rainy season to early dry season in the semiarid Caatinga (Medeiros et al 2012). Activity was strongly negatively correlated to temperature and positively correlated to prey abundance (Medeiros et al 2012). The diets of both D. gigantea and D. quadriceps have been shown to be predominantly scavenged invertebrates, but include live prey, seeds and fruits (Zahl 1959, Fourcassié and Oliviera 2002, Araújo and Rodrigues 2006.…”

Pro- and Anticonvulsant Effects of the Ant Dinoponera quadriceps (Kempf) Venom in Mice

“…Dinoponera quadriceps (Kempf) is a queenless Ponerinae ant found in the Northeastern Brazil (Medeiros et al 2012). Because very few studies have focused on the venoms of ants as sources of excitatory and inhibitory neuronal modulators, the aim of this study was to investigate the effects of the intracerebroventricular injection of the D. quadriceps ant venom on mice behavior in the open field.…”

Temporal variations of Collembola (Arthropoda: Hexapoda) in the semiarid Caatinga in northeastern Brazil

“…Studies of the effects of temporal variations of climatic factors on the Caatinga fauna, especially in terms of its invertebrates, have been scarce in light of the wide diversity of this group of organisms (AGUIAR & MARTINS 1997, ZANELLA & MARTINS 2003, GUSMÃO & CREÃO-DUARTE 2004, IANNUZZI et al 2006, HERNÁNDEZ 2007, ARAÚJO et al 2010, VASCONCELLOS et al 2010, MEDEIROS et al 2012 The present study sought to evaluate the Collembola fauna in a semiarid area of Caatinga vegetation in northeastern Brazil and identify the climatic variables that influence species richness, individual abundances, and the structural composition of that guild. This represents one of the few studies undertaken in the Caatinga biome that has evaluated the effects of temporal variations in climatic elements on invertebrates at the species level.…”