Spatial Distribution and Architecture of Acromyrmex landolti Forel (Hymenoptera, Formicidae) Nests in Pastures of Southwestern Bahia, Brazil

Abstract

Ants of the genera Atta and Acromyrmex (Myrmicinae: Attini) are in general pests for agricultural and pasture areas. In southwestern Bahia pastures, in Brazil, Acromyrmex landolti Forel occurs at intermediate densities of 260 nests ha-1. In spite of its economic importance, there is not enough research on the bioecological aspects of such species. This paper aims to study the spatial distribution and the architectural pattern of A. landolti nests, as well as to establish the foundations for the improvement of strategies for controlling the pest. The research was carried out during the period of June 2011 and May 2012, in an area of pastures measuring 2.7 ha, in Itapetinga, in Bahia. Twenty five nests were selected. The external mound area, height of the tower, distance between the tower and the external mound area, as well as the tower diameter were all registered. In order to describe the internal architecture, the same nests were completely excavated and five were molded in cement. The spatial distribution of the nests is of aggregated type. The towers height is 2.1 cm and the average diameter is 1.2 cm. The amount of loose soil is of about 8.0 cm from the tower, with an average area of 472.9±312.5 cm² and average volume of 1.4 L±0.9. The depth of the nests varies between 7.0 and 78.0 cm, with an average of 33.2±21.29 cm. The nests have, in average, 4.4±2.0 chambers, being two nests with just one chamber (8%) and another nest (4%) with 11 chambers.

Nest Biology and Demography of the Fungus-Growing Ant Cyphomyrmex lectus Forel (Myrmicinae; Attini) at a Disturbed Area Located in Rio Claro, SP, Brazil

“…Leal et al, 2011;Ramos-Lacau et al, 2012) when compared to Atta and Acromyrmex genera (Wirth et al, 2003;Silva Junior et al, 2013). Here, one single circular nest-entrance hole without a well-formed nest mound was observed in C. lectus.…”

Population Dynamics of Acromyrmex crassispinus (Forel) (Hymenoptera: Formicidae) and Attacks on Pinus taeda Linnaeus (Pinaceae) plantations

“…In contrast, Acromyrmex balzani (Emery) and Acromyrmex landolti Forel have aggregated spatial distribution, in fragments of grassland. This type of distributions may reflect the habitat heterogeneity or can be relate to the strategy of colony foundation (SousaSouto et al, 2013;Silva Junior et al, 2013).…”

Locating, collecting, and maintaining colonies of fungus-farming ants (Hymenoptera: Myrmicinae: Attini)

“…Constant humidity is maintained in the containers by lining them with poured plaster or with a plug of cotton thoroughly saturated with water. Many sorts of plastic containers may be used, including plastic Petri dishes, (da Silva Júnior et al, 2013;Silva et al, 2011;Verza et al, 2007;Weber, 1941Weber, , 1945Weber, , 1946Weber, , 1947Weber, , 1969bWeber, , 1972b)…”

“…This paper focuses mostly on the non-leaf-cutting fungus-farming ants, including the lower attine ants as well as Trachymyrmex and Sericomyrmex. For information on the leaf-cutting ant genera Acromyrmex and Atta, including methods for field collecting and laboratory rearing, see: Weber (1937); Fernandez-Marin et al (2003); Verza et al (2007); Fernandez et al (2015); Araújo & Della Lucia (1997); Mariconi (1970); Montoya Lerma et al (2006); Moreira et al (2004) ;Silva Junior et al (2013); Soares et al (2006); Della Lucia & Moreira (1993); Forti et al (2011); Morgan (1991); Della Lucia (2011). Nonleaf-cutting fungus-farming ant species do not cut fresh plant material but instead variously use insect frass, flower petals, seeds, (possibly) insect carcasses, and other organic detritus on which to grow their fungal cultivars.…”