ABSTRACT

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To investigate whether similar physiognomic areas support similar faunas, the richness, similarity, and community structure of the ant fauna attracted to baits in an area of the Brazilian Cerrado sensu stricto at the core of the domain and in two Cerrado 'islands' (one of sensu stricto and another of 'cerradão') were compared. In each locality, four collecting events were performed (two during the day and two at night) capturing ants attracted to 400 sardine baits (200 in soil, 200 in vegetation). Ants of six subfamilies, 33 genera, and 121 species were identified visiting baits in the three areas (180 species estimated). The most speciose genera were Camponotus (27 species), Pheidole (13), Solenopsis (11), and Crematogaster (8). The similarity values between pair sites can be considered medium in relation to other studies. The highest value was recorded for the core area and the 'island' of Cerrado sensu stricto (Morisita-Horn = 0.57). The two Cerrado 'islands' were found to be 0.44 similar and the core area and the 'cerradão' 0.41 similar. The ordination analysis (non-metric multidimensional scaling) revealed discontinuities in species distributions between areas of Cerrado sensu stricto and 'cerradão,' and distinctive ant faunas relative to the temporal (nocturnal and diurnal) and foraging niches (ground and vegetation). The ant fauna at ground level in the 'cerradão' and Cerrado sensu stricto showed the greatest dissimilarity. The data suggest that areas of Cerrado are characterized by relatively high local ant fauna richness, and that community structure is influenced by the distance between sites and the diversity of vegetation.

Mature nests of the Neotropical myrmicine ant Blepharidatta conops are short blind vertical cylinders, in general excavated directly in the ground. Nurse workers hold the larvae in their mandibles while resting along the nest's walls. When nests are visited or inhabited by myrmecophiles and/or predators, especially Histeridae beetles (adults and larvae), ant workers hide their brood in the nest's subsidiary chamber, the entrance of which is then blocked by the peculiar phragmotic disk of the single ergatoid queen in the colony. The extremely modified head and anterior slope of the pronotum of the queen, that jointly form the almost circular frontal disk, represent a new kind of cryptic phragmosis in ants; exceptional modifications of these structures, which are covered with intricate sculpture, enables the queen to behave as a living gate to the brood chamber, yielding entering nestmates when tapped by them on the disk. Workers use fine grained debris to build a wall at the beginning of the brood's chamber, such that the entrance opening matches the diameter of the queen's frontal disk. Observations in several different Brazilian localities revealed that the queens' frontal disk bear unique locality-specific sculpturing patterns, possibly due to viscous population structures caused by the limited dispersal by virgin queens, whose wing buds never develop.

Formigas como bioindicadores da qualidade do solo em sistema intergrado lavoura-pecuária.Ciência Rural, v.44, n.5, mai, 2014. INTRODUÇÃOO cenário atual da produção agropecuária, com o uso intensivo do solo para produzir grãos e carne bovina, pode provocar alterações nos ecossistemas, em várias escalas, principalmente afetando a estrutura trófi ca da comunidade biológica, além de alterações nos atributos químicos e físicos (MARCHÃO, 2009). As formigas são componentes importantes desta comunidade do solo, principalmente por seus atributos ecológicos, como grande biomassa e atividades que realizam na engenharia de seus ninhos, atuando na aeração do solo e no banco de sementes. As formigas apresentam grande diversidade e atualmente são consideradas14.954 espécies e subespécies válidas, distribuídas em 22 subfamílias em I Universidade Federal da G rande Dourados (UFGD), Dourados, MS, Brasil.

, pela orientação durante todos estes anos pesquisando formigas.

This paper describes habitat and geographic correlates of ant diversity in Serra da Bodoquena, a poorly surveyed region of central-western Brazil. We discuss leaf-litter ant diversity on a regional scale, with emphasis on the contribution of each of the processes that form the evolutionary basis of contemporary beta diversity. The diversity of leaf-litter ants was assessed from a series of 262 Winkler samples conducted in two microbasins within a deciduous forest domain. A total of 170 litter-dwelling ant species in 45 genera and 11 subfamilies was identified. The data showed that the study areas exhibited different arrangements of ant fauna, with a high turnover in species composition between sites, indicating high beta diversity. Our analysis suggests that the biogeographic history of this tropical dry forest in the centre of South America could explain ant assemblage structure more than competitive dominance. The co-occurrence analysis showed that species co-occur less often than expected by chance in only two of the localities, suggesting that, for most of the species, co-occurrences are random. The assessment of the structure of the diversity of litter-dwelling ants is the first step in understanding the beta diversity patterns in this region of great biogeographic importance.

ABSTRACT. A checklist composed of 105 species of parasitic Hymenoptera, which includes the non-aculeate Apocrita, recorded in the state of Mato Grosso do Sul (MS), Brazil, is presented. A new list, containing 153 genera obtained in recent surveys is also presented; out of these 131 are new records. The major knowledge gaps for these organisms in the State and the prospects for future studies for these organisms are discussed.