Seasonality and distribution of Coleoptera families (Arthropoda, Insecta) in the Cerrado of Central Brazil

ABSTRACT Coleoptera order in Brazil presents 105 families with approximately 28,000 species. The life cycle and diversity of Coleoptera are strongly influenced by climate and vegetation. The objective of this study was to evaluate the seasonality and distribution of Coleoptera families in an area of the Cerrado in the Federal District (DF) of Brazil. The insects were collected monthly, between June 2015 and May 2016, using a light trap activated only in nights with a new moon, in an area of cerrado sensu stricto in Planaltina/DF, Brazil. The data were correlated with climatic variables. A total of 21,100 Coleoptera specimens belonging to 34 families were collected, with Melolonthidae (n = 11,075), Carabidae (n = 2,522), Scarabaeidae (n = 2,506), Bostrichidae (n = 1,196), and Chrysomelidae (n = 1,086) being the most abundant. Coleoptera were significantly more abundant in the first half of the rainy season. There was a significant and positive correlation between the abundance of Coleoptera and the climatic variables temperature and precipitation. The data presented in this study are related to an atypical year under the strong influence of the El Niño phenomenon, which may influence the abundance of Coleoptera. Circular analysis revealed that Coleoptera, and the most abundant families, presented seasonality throughout the year with a grouped distribution at the beginning of the rainy season (October to December). This study demonstrates that the richness and abundance of the Coleoptera order, in the Cerrado, is strongly influenced by the characteristic climatic seasons of the biome.

Beetle diversity in fragmented thornscrub and isolated trees / Diversidade de coleópteros em um fragmento do bioma thornscrub e árvores isoladas

Abstract Due to land use change mainly for induced agriculture, Tamaulipan thornscrubin northeast Mexico has been cleared and transformed into small patches of vegetation as small as isolated trees surrounded by agricultural fields. In this study, we explored how tree isolation or growing inside a fragment of remnant vegetation influence diversity of coleopterans in two plant species (Prosopis laevigata (Humb. &Bonpl.exWilld.) M.C. Johnst. (mesquite) and Ebenopsis ebano (Berl.) Barneby (Texas ebony). We found 72 coleopteran morphospecies; fifteen occurred mainly in remnant fragments and ten mainly in isolated trees. There were more insects under isolated mesquites than under those immersed in remnant fragments, while in Texas ebony the highest beetle density for isolated trees coincided with periods of bean and maize in surrounding agriculture.

Resumo Devido a mudança de uso da terra para induzir principalmente a agricultura, o bioma thornscrub no nordeste México tem sido transformado em fragmentos pequenos como árvores isoladas rodeadas por campos agrícolas. Neste estudo exploramos como o isolamento das árvores influi na diversidade de coleópteros em duas espécies de plantas (Prosopis laevigata (Humb. & Bonpl.ex Willd) M.C. Johnst. (mesquite) e Ebenopsis ebano (Berl.) Barneby (Texas ebony). Encontramos 72 morfospecies do coleópteros; quinze ocorreram principalmente em fragmentos remanescentes e dez em árvores isoladas. No estudo houve mais insetos nas “mesquite” isoladas do que nos fragmentos remanescentes do bioma thornscrub, enquanto que em “Texas ebony” a densidade alta de coleópteros para árvores isoladas coincidiu com períodos de produção de feijão e milho na agricultura ao redor.

Notes on insect diversity of Indian Cycas species.

The question of an analogue evolution of plant - insect interaction in gymnosperms has remained unanswered until recently, in spite of indications of insect pollination in the extant cycad genera. Earlier observations on insect pollination have now been verified by convincing experiments with several cycads in which anemophilous pollination was excluded. Insects have long been known to visit cycad cones and now it is established that in rest of the cycad species where both male and female reproductive organs are organized in compact cones, these insects help in the pollination. But Cycas is the only genus where female megasporophylls do not form a cone and its pollination mechanism has not been fully comprehended. The present investigation was carried out in the natural habitats of Cycasspecies from the Western Ghats, India. Five coleopteran insects were found abundantly in the male cones of Cycas and our observations on the role of these insects led us to believe that Cycas among cycads which appear to be true remnants of pteridospermous line have somehow has also maintained mutualism with the primitive plant chewing insects like coleopterans couldbe the results of an ancient co-evolution.

Coleoptera (Insecta) as forest fragmentation indicators in the Rio Negro sub-region of the Pantanal, Mato Grosso do Sul, Brazil

The purpose of this study was to evaluate the integrity of two forest fragments in Rio Negro Pantanal sub-region, using coleopterans as environmental indicators. The study was carried out at Santa Emilia Farm in the Rio Negro sub-region, municipality of Aquidauana, Mato Grosso do Sul (19º 30' 18'' S and 55° 36' 45'' W). Two sites were selected, locally denominated as "cordilheiras" (narrow and elongated strands of elevated soil), one with low degree of anthropic disturbance (CL) and the other, currently undergoing restoration process (TD). The sampling sites were determined using a GPS device. Ten pit-fall traps containing water and detergent were used for the specimens sampling, which were screened and identified. Abundance, richness, diversity and similarity were determined. Abundance was higher for CL (n = 277) than for TD (n = 251). The same was observed for the diversity indices, CL showed H' = 2.83 bit.individual-1 and TD = 2.48 bit.individual-1, confirming the interferences made for abundance. Specimens of ten families were captured in CL area and seven families in TD area, indicating higher richness in CL, when compared to TD. The linear correlation coefficient (p > 0.05) indicates that both areas are significantly different, showing similarity value of 66.7%. The data show that the structure and disturbance degree in the environment integrity influence the composition of beetles fauna, causing the increase of abundance, richness and diversity in anthropogenic environments undergoing the early stage of regeneration.

Este trabalho avalia a integridade de dois fragmentos de floresta da sub-região do Rio Negro do Pantanal, utilizando coleópteros como indicadores. O estudo foi conduzido na Fazenda Santa Emília, na sub-região do Rio Negro, município de Aquidauana, Estado de Mato Grosso do Sul (19º 30' 18'' S e 55° 36' 45'' W). Dois estreitos fragmentos de floresta (localmente conhecida com cordilheira), situados em terrenos um pouco mais elevados, um com baixo grau de perturbação antrópica (CL) e o outro em processo de restauração (TD). Os sítios de amostragem foram marcados com GPS. Dez armadilhas de queda contendo água e detergente foram utilizadas. Abundância, riqueza de espécie, diversidade e similaridade foram determinadas. Abundância foi maior para CL (n = 277) do que para TD (n = 251). A mesma tendência foi observada para índices de diversidade, CL com 2,83 e TD com 2,48. Indivíduos de dez famílias foram capturados na área CL e de sete famílias na área TD, indicando mais alta riqueza em CL. O coeficiente de correlação linear (p > 0,05) indica que ambas as áreas são significantemente diferentes, com valor de similaridade de 66,7%. Os dados mostram que o grau de perturbação e estrutura da integridade ambiental influencia a composição da fauna de besouros, causando o aumento em abundância, riqueza e diversidade nos dois fragmentos estudados.

Fimicolous histeridae coleoptera in Campo Grande, MS, Brazil

Fecal masses recently excreted and/or almost dry were collected weekly in a pasture of Brachiaria decumbens Stapf, from May 1990 to April 1992. The feces were conditioned in 15-liter opaque plastic buckets, containing lateral and top openings, where flasks were fastened for capturing Histeridae beetles present in these masses. Three thousand two hundred ninety-nine specimens were collected belonging to 11 species in the Genus: Phelister, Hister, Euspilotus, Acritus, and Xerosaprinus. The most frequent, constant, and abundant species were Phelister sp. nr. carinifrons and P. haemorrhous.

Massas fecais recém-excretadas até quase secas foram coletadas semanalmente em uma pastagem de Brachiaria decumbens Stapf, no período de maio de 1990 a abril de 1992. As fezes foram acondicionadas em baldes plásticos opacos com capacidade para 15 litros, contendo aberturas lateral e no topo, onde foram fixados frascos para a captura dos besouros histerídeos presentes nas massas fecais. Foram coletados 3.299 exemplares, pertencendo a 11 espécies dos gêneros: Phelister, Hister, Euspilotus, Acritus e Xerosaprinus. As espécies mais freqüentes, constantes e abundantes foram Phelister sp. nr. carinifrons e P. haemorrhous.