RESUMO
This study provides a list of the ground-dwelling ant species in Nhecolândia, Pantanal, Mato Grosso Sul, Brazil. The Pantanal is the largest tropical wetland in the world and is currently under strong anthropic pressure. Ground-dwelling ants were collected in three sites: (1) a forest regeneration area; (2) a pasture area; and (3) an area of secondary native vegetation. In each site, 120 samples were collected using pitfall traps in the dry and rainy seasons of 2016. Additional samplings were performed with Winkler extractors (30 leaf-litter samples) and manually, also in dry and rainy seasons of 2016. In total, we collected 172 species, which, summed with the additional records from literature, raise the number of ant species recorded in Nhecolândia to 184 in 42 genera and nine subfamilies. Eleven species were recorded for the first time in the state of Mato Grosso do Sul. Also, the survey adds two new species records to Brazil. Besides contributing to the inventory of the ant species present in the Pantanal biome, the present study provides an important resource for future conservation plans for this threatened ecoregion.(AU)
Assuntos
Animais , Himenópteros/anatomia & histologia , Himenópteros/classificação , Biodiversidade , Conservação dos Recursos NaturaisRESUMO
Abstract This study provides a list of the ground-dwelling ant species in Nhecolândia, Pantanal, Mato Grosso Sul, Brazil. The Pantanal is the largest tropical wetland in the world and is currently under strong anthropic pressure. Ground-dwelling ants were collected in three sites: (1) a forest regeneration area; (2) a pasture area; and (3) an area of secondary native vegetation. In each site, 120 samples were collected using pitfall traps in the dry and rainy seasons of 2016. Additional samplings were performed with Winkler extractors (30 leaf-litter samples) and manually, also in dry and rainy seasons of 2016. In total, we collected 172 species, which, summed with the additional records from literature, raise the number of ant species recorded in Nhecolândia to 184 in 42 genera and nine subfamilies. Eleven species were recorded for the first time in the state of Mato Grosso do Sul. Also, the survey adds two new species records to Brazil. Besides contributing to the inventory of the ant species present in the Pantanal biome, the present study provides an important resource for future conservation plans for this threatened ecoregion.
RESUMO
Abstract This study provides a list of the ground-dwelling ant species in Nhecolândia, Pantanal, Mato Grosso Sul, Brazil. The Pantanal is the largest tropical wetland in the world and is currently under strong anthropic pressure. Ground-dwelling ants were collected in three sites: (1) a forest regeneration area; (2) a pasture area; and (3) an area of secondary native vegetation. In each site, 120 samples were collected using pitfall traps in the dry and rainy seasons of 2016. Additional samplings were performed with Winkler extractors (30 leaf-litter samples) and manually, also in dry and rainy seasons of 2016. In total, we collected 172 species, which, summed with the additional records from literature, raise the number of ant species recorded in Nhecolândia to 184 in 42 genera and nine subfamilies. Eleven species were recorded for the first time in the state of Mato Grosso do Sul. Also, the survey adds two new species records to Brazil. Besides contributing to the inventory of the ant species present in the Pantanal biome, the present study provides an important resource for future conservation plans for this threatened ecoregion.
RESUMO
Emigration of a colony of the leaf-cutting ant Acromyrmex heyeri Forel (Hymenoptera, Formicidae). Colony migration is a poorly studied phenomenon in leaf-cutting ants. Here we report on the emigration of a colony of the leaf-cutting ant A. heyeri in Brazil. The colony emigrated to a new location 47.4 m away from the original nest site, possibly because it had undergone considerable stress due to competitive interactions with a colony of Acromyrmex crassispinus.
Emigração de uma colônia da formiga cortadeira Acromyrmex heyeri Forel (Hymenoptera, Formicidae). A migração de colônias de formigas cortadeiras é um fenômeno pouco estudado. Nesse estudo, nós relatamos a emigração de uma colônia da formiga cortadeira A. heyeri no Brasil. A colônia emigrou 47,5 m de distância do seu ninho original para um novo local, provavelmente porque sofreu um estresse considerável devido à interações competitivas com uma colônia de Acromyrmex crassispinus.
RESUMO
The spatial distribution of insects is essential to perform control strategies, to improve sample techniques and to estimate economic losses. We aimed to determine the spatial distribution of nests of Acromyrmex crassispinus (Forel) in Pinus taeda plantations. The experiments were carried out in P. taeda plantations with different ages (treatments: recently-planted, three and six-year old plants). The study took place in Rio Negrinho and in Três Barras, SC. Three plots of one hectare were delimited in each treatment, and plots were divided in 64 sample units. The analysis of the dispersion index [variance/mean relationship (I), index of Morisita (Iδ) and k exponent of negative binomial distribution] showed that the majority of the samplings presented random distribution. Among the three distributions of probabilities studied: Poisson, positive binomial and negative binomial, the Poisson distribution was the best model to fit the spatial distribution of A. crassispinus nests in all samplings. The result was a random distribution in the plantings of different ages.
Assuntos
Animais , Formigas , Comportamento de Nidação , Pinus taeda , DemografiaRESUMO
The spatial distribution of insects is essential to perform control strategies, to improve sample techniques and to estimate economic losses. We aimed to determine the spatial distribution of nests of Acromyrmex crassispinus (Forel) in Pinus taeda plantations. The experiments were carried out in P. taeda plantations with different ages (treatments: recently-planted, three and six-year old plants). The study took place in Rio Negrinho and in Três Barras, SC. Three plots of one hectare were delimited in each treatment, and plots were divided in 64 sample units. The analysis of the dispersion index [variance/mean relationship (I), index of Morisita (Iδ) and k exponent of negative binomial distribution] showed that the majority of the samplings presented random distribution. Among the three distributions of probabilities studied: Poisson, positive binomial and negative binomial, the Poisson distribution was the best model to fit the spatial distribution of A. crassispinus nests in all samplings. The result was a random distribution in the plantings of different ages.