Ocorrência De Formigas Cortadeiras Na Região Da Depressão Central Do Estado Do Rio Grande Do Sul

Abstract

Com o objetivo de identificar as espécies de formigas cortadeiras que existem na região da Depressão Central do Estado do Rio Grande do Sul, de verificar sua predominância e distribuição geográfica, realizou-se um levantamento em 51 municípios. Foram coletadas 40 amostras de formigas de cada município no segundo semestre de 1999. A identificação das formigas e a interpretação dos dados foi realizada no Departamento de Fitossanidade da Faculdade de Agronomia "Eliseu Maciel" da Universidade Federal de Pelotas. Na análise das 2.058 amostras de formigas, constatou-se a presença de: Atta sexdens piriventris Santschi, 1919; Acromyrmex laticeps (Emery, 1905); Acromyrmex crassispinus (Forel, 1909); Acromyrmex heyeri (Forel, 1899); Acromyrmex lundi (Guerin, 1838); Acromyrmex ambiguus (Emery, 1887); Acromyrmex striatus (Roger, 1863); Acromyrmex lobicornis (Emery, 1887); Acromyrmex coronatus (Fabricius, 1804) e Acromyrmex landolti balzani Emery, 1890. As espécies predominantes foram Acromyrmex lundi, Atta sexdens piriventris, A. ambiguus, A. heyeri, A. striatus e A. laticeps, representando, respectivamente, 23,91%, 22,89%, 16,86%, 14,04%, 6,85% e 6,70% do total amostrado, ocorrendo em 84,31%, 60,78%, 70,59%, 84,31%, 78,43% e 88,24% dos municípios, respectivamente. As demais espécies (A. crassispinus, A. lobicornis, A. landolti balzani e A. coronatus) foram pouco freqüentes, representando juntas 6,27% do total, sendo por isso, consideradas de ocorrência rara nesta região.

Occurrence of Leaf-Cutting and Grass-Cutting Ants of the Genus Atta (Hymenoptera: Formicidae) in Geographic Regions of Brazil

“…For the Brazilian regions, few studies on the subject have been conducted, highlighting the pioneering works of Gonçalves (1942Gonçalves ( , 1945Gonçalves ( , 1951Gonçalves ( , 1955Gonçalves ( , 1960Gonçalves ( , 1961Gonçalves ( , 1967Gonçalves ( , 1971 and Kempf (1972), who generated a broader knowledge on the distribution of species in the different regions of Brazil, and Paula (1956) for the State of Paraná andMariconi (1966, 1970) for the State of São Paulo. More recent are the studies developed by Loeck and Grützmacher (2001) and Grürzmacher et al (2002), for leafcutting ants in Rio Grande do Sul and Corrêa et al (2005) and Brito et al (2012) for the Northeastern region, States of Alagoas and Bahia, respectively. The contributions on timely reports of the occurrence of leaf-cutting ants, such as Carvalho and Tarragô (1982) for Rio Grande do Sul, Delabie (1989) for Bahia and Souza et al (2009) for Alagoas are also noteworthy.…”

The effect of homeopathic preparations on the activity level of Acromyrmex leaf-cutting ants

“…To support their colonies, the Acromyrmex spp. ants search out and harvest young plant parts, such as sprouts, buds, leaves, and flowers, which they carry back to their nests in order to cultivate a symbiotic fungus, Leucoagaricus gongylophorus; this fungus is the main food source for the colony (ROCES, 1990;MUELLER, 2002 While the intense foraging activity of leaf-cutting ants can damage cropped plants in a short period of time, they play an important role in the ecosystem (GRURZMACHER et al, 2002). They promote changes in soil structure and nutrient content by recycling organic matter that is deposited in the vicinity of their nests (DELABIE et al, 2000).…”

Ocorrência de formigas cortadeiras em campos de altitude no sul do Brasil

“…lobicornis and Ac. Ambiuus, were the species with the lowest frequency and abundance for the high-altitude grasslands, In the work conducted by Grurzmacher et al, (2002) Gusmão et al, (2002) identified 7 species of leafcutting ants with predominance of Ac. lundii, Ac.…”