Morphometric Analysis of Longipalpis (Diptera: Psychodidae) Complex Populations in Mato Grosso do Sul, Brazil.

Owing to the existence of cryptic species that are difficult to distinguish morphologically, the search for new taxonomic characters and methods for identifying and classifying sand flies continues. Lutzomyia longipalpis (Lutz & Neiva, 1912) and Lutzomyia cruzi (Mangabeira, 1938) (Diptera: Psychodidae) are two such species that occur in sympatry in some regions of Mato Grosso do Sul State (MS). Twenty females and twenty males from each of the five populations of Lu. longipalpis and one population of Lu. cruzi from MS were examined. An outlying population of Lu. longipalpis from Estrela de Alagoas, State of Alagoas, was used to compare the degree of divergence among the groups in MS. Specimens were cleared, mounted on slides, identified, and measured using LAS-Leica. The principal component analysis of morphometric characters showed a high degree of variation among females, while males varied to a lower degree. The populations of Alagoas and Miranda demonstrated the greatest variation. The first region, Alagoas, is geographically distant from the others and occurs under distinctly different ecological conditions, which likely accounts for the variation. Further studies should be made to elucidate the factors that contribute to the differences found between the populations of MS.

Colony cycle of the social wasp Mischocyttarus consimilis Zikán (Hymenoptera, Vespidae)

Colony cycle of the social wasp Mischocyttarus consimilis Zikán (Hymenoptera, Vespidae). This study describes some aspects of the colony cycle of the Neotropical social wasp Mischocyttarus consimilis, from data obtained under field conditions. Our results showed that the colony cycle in M. consimilis is annual and asynchronous in relation to the months of the year. The colonies remained active for approximately eight months. Most of the abandonments were associated with natural causes, and were most frequent in the pre-emergence stage. The nests were constructed preferentially in man-made structures, especially in sites protected from direct sunlight and rain. Colony foundation was either by haplometrosis or pleometrosis, being the first form predominant.

Ciclo colonial da vespa social Mischocyttarus consimilis Zikán (Hymenoptera, Vespidae). Este estudo descreve alguns aspectos do ciclo colonial da vespa social Neotropical Mischocyttarus consimilis, sendo realizado em condições de campo. Os resultados desse estudo mostraram que o ciclo colonial em M. consimilis é anual, bem como assincrônico em relação aos meses do ano. Em geral, as colônias permanecem em atividade por aproximadamente oito meses. Os abandonos de colônia estão associados principalmente a causas naturais, e são mais freqüentes na fase colonial de pré-emergência. Os ninhos são estabelecidos preferencialmente em construções humanas, especialmente em locais protegidos da incidência direta de luz solar e água da chuva. Fundações de colônia ocorrem por uma ou outra forma haplometrose ou pleometrose, sendo a primeira predominante.

Nest architecture, colony productivity, and duration of immature stages in a social wasp, Mischocyttarus consimilis.

Tis study examined the nest architecture, colony productivity, and duration of the immature stages of the social wasp Mischocyttarus consimilis Zikán (Hymenoptera: Vespidae). The study was carried out under field conditions. Nests of M. consimilis consist of a single uncovered comb, which is attached to the substratum by a single petiole. The data for the nest architecture showed a positive and significant correlation between the size of the comb and the diameter of the petiole, and also between the height and diameter of the cells. The nests were constructed on horizontal, vertical, and sloping substrata with no apparent preference for a specific orientation. The colonies produced 72.9 cells and 40.7 adults on average. The mean frequency of productive cells was 33.3%, and 19.4% of the cells were reused. The mean duration of the immature stages combined was 69.7 days and the egg, larval, and pupal stages had mean durations of 14.9, 36.0, and 18.8 days, respectively. The duration of each immature stage was significantly shorter in the warm-humid season, and the larval and pupal stages were shorter during the colony pre-emergence stage.

Nest structure and occurrence of three species of Azteca (Hymenoptera, Formicidae) in Cecropia pachystachya (Urticaceae) in non-floodable and floodable pantanal areas / Arquitetura de ninho e ocorrência de três espécies de Azteca (Hymenoptera, Formicidae) em Cecropia pachystachya (Urticaceae) em ambiente alagável e não alagável no Pantanal

Thirty Cecropia pachystachya trees were examined in non-floodable and floodable areas to investigate the association between C. pachystachya and Azteca ants in the Pantanal of Mato Grosso do Sul, Brazil. The species Azteca ovaticeps, Azteca isthmica, and Azteca alfari were found nesting inside domatia of C. pachystachya. A. ovaticeps was the most frequent species in the trees in the floodable area, while A. isthmica and A. alfari, in the non-floodable area. A. ovaticeps and A. isthmica maintained more entrance/exit holes in comparison to A. alfari. All Azteca species maintained entrance/exit holes in the closest domatia to the apical area of the branch, due to proximity to Müllerian and pearl bodies, suggesting that these species of Azteca were influenced by their environment during evolution and became specialized. All internodal septa of each examined branch were perforated by ants, indicating the branches were inhabited by a single colony.

Foram analisadas 30 plantas de Cecropia pachystachya em cada ambiente alagável e não alagável no Pantanal sul-mato-grossense, Brasil, com o objetivo de investigar a associação entre formigas Azteca e C. pachystachya. Foram encontradas as espécies Azteca ovaticeps, Azteca isthmica e Azteca alfari nidificando nas domáceas da planta. A. ovaticeps foi mais frequente em plantas de área alagável, enquanto A. isthmica e A. alfari em plantas em área não alagável. A. ovaticeps e A. isthmica apresentaram maior quantidade de orifícios de entrada/saída em relação à A. alfari e todas as espécies mantêm próximo da região apical do ramo, orifícios de entrada/saída nas domáceas, devido à proximidade com os corpúsculos müellerianos e pérola. Isto é, essas espécies de Azteca especializaram-se ao longo da evolução influenciadas pelo ambientes. Todos os septos internodais de cada ramo analisados apresentaram-se perfurados pelas formigas, sugerindo que os mesmos são habitados por uma única colônia.

Diversidade de formigas epigéicas (Hymenoptera: Formicidae) em capões do Pantanal Sul Matogrossense: relações entre riqueza de espécies e complexidade estrutural da área / Ant diversity (Hymenoptera: Formicidae) from capões in Brazilian Pantanal: relationship between species richness and structural complexity

A riqueza de formigas de capões do Pantanal brasileiro foi amostrada e relacionada com a complexidade estrutural das áreas. As formigas foram coletadas com armadilhas de solo do tipo pitfall em 28 capões na Fazenda Rio Negro, Município de Aquidauana, MS. A complexidade estrutural dos capões foi avaliada através de estimativa da densidade da vegetação e da espessura da serapilheira próximo às armadilhas. Setenta e uma espécies foram encontradas, pertencentes a 26 gêneros e sete subfamílias, das quais Ectatomma edentatum Roger (Formicidae: Ectatomminae) e uma espécie de Pheidole foram as mais freqüentes. Somente foi encontrada relação positiva entre a riqueza da comunidade de formigas e a densidade da vegetação herbácea, corroborando a idéia de que a heterogeneidade do ambiente é um fator determinante para a coexistência e diminuição de competição entre espécies.

Species richness of epigeic ants was surveyed in forest islands named capões of Brazilian Pantanal and related with their structural complexity. The ants were collected using pitfall traps in 28 capões from Rio Negro Farm, in Aquidauana municipality, Mato-Grosso do Sul state, Brazil. The structural complexity of capões was evaluated by measuring vegetation density and litter quantity near the pit-fall traps. Seventy-one species, distributed in 26 genera and seven sub-families were found. Ectatomma edentatum Roger (Formicidae: Ectatomminae) and one species of Pheidole were the most frequent species. Species richness was positively correlated only with herbaceous vegetation density of capões, supporting the idea that the increase in environmental heterogeneity diminishes species competition, allowing species co-occurrence.

[Ant diversity (Hymenoptera: Formicidae) from capões in Brazilian Pantanal: relationship between species richness and structural complexity]. / Diversidade de formigas epigéicas (Hymenoptera: Formicidae) em capões do Pantanal Sul Matogrossense: relações entre riqueza de espécies e complexidade estrutural da área.

Species richness of epigeic ants was surveyed in forest islands named capões of Brazilian Pantanal and related with their structural complexity. The ants were collected using pitfall traps in 28 capões from Rio Negro Farm, in Aquidauana municipality, Mato-Grosso do Sul state, Brazil. The structural complexity of capões was evaluated by measuring vegetation density and litter quantity near the pit-fall traps. Seventy-one species, distributed in 26 genera and seven sub-families were found. Ectatomma edentatum Roger (Formicidae: Ectatomminae) and one species of Pheidole were the most frequent species. Species richness was positively correlated only with herbaceous vegetation density of capões, supporting the idea that the increase in environmental heterogeneity diminishes species competition, allowing species co-occurrence.