ABSTRACT
ABSTRACT Temperature affects the body size of animals, which is an important trait in natural and sexual selection. Insects do not have complex mechanisms of temperature control, thus temperature changes affect their life aspects, from enzymatic reactions to behavior. The amount of fat stored by insects is also influenced by temperature and constitutes a tissue with biosynthetic and metabolic activity, acting as an energy reservoir. We assessed the effect of environmental temperature due to elevation and seasonal temperature variations on body size and condition of two dung beetles species: Canthon rutilans cyanescens and Dichotomius sericeus (Coleoptera: Scarabaeinae). Both species are abundant in southern Brazilian forests, but they differ in habits: the first is a diurnal roller whereas the later is a nocturnal tunneler. Summer months and sites with lower elevations and higher temperatures presented larger C. rutilans cyanescens. A linear relationship exists between body size and soil temperatures, whereas the temperature positively influences the body length. Furthermore, C. rutilans cyanescens from cooler sites had more body fat. Individuals of D. sericeus were also larger in summer months, however, we did not find differences in the proportion of fat or a relation between body size and temperature. Thus, the body size of dung beetle species varies in relation to temporal factors, as both species are larger in summer. More interesting was to observe that the species with a diurnal habit, even though smaller in colder places, has a higher proportion of fat, which indicates an evolutionary response to environmental pressure.
ABSTRACT
ABSTRACT The Brazilian Atlantic Forest is one of the world's biodiversity hotspots, and is currently highly fragmented and disturbed due to human activities. Variation in environmental conditions in the Atlantic Forest can influence the distribution of species, which may show associations with some environmental features. Dung beetles (Coleoptera: Scarabaeinae) are insects that act in nutrient cycling via organic matter decomposition and have been used for monitoring environmental changes. The aim of this study is to identify associations between the spatial distribution of dung beetle species and Atlantic Forest structure. The spatial distribution of some dung beetle species was associated with structural forest features. The number of species among the sampling sites ranged widely, and few species were found in all remnant areas. Principal coordinates analysis indicated that species composition, abundance and biomass showed a spatially structured distribution, and these results were corroborated by permutational multivariate analysis of variance. The indicator value index and redundancy analysis showed an association of several dung beetle species with some explanatory environmental variables related to Atlantic Forest structure. This work demonstrated the existence of a spatially structured distribution of dung beetles, with significant associations between several species and forest structure in Atlantic Forest remnants from Southern Brazil.
ABSTRACT
Diversity of Scarabaeidae s. str. (Coleoptera) in the Reserva Biológica Guaribas, Mamanguape, Paraiba, Brazil: a comparison between Atlantic Forest and northeast's Tabuleiro. Scarabaeid beetles consume dung and carcasses of large vertebrates. Guilds of scarabeids were compared between Forest and Tabuleiro at the Reserva Biológica Guaribas, Mamanguape, in the state of Paraíba. Samples were collected monthly from November 2001 to April 2002 in Forest and Tabuleiro. Insects were collected by using 24 pitfall-traps, 12 in each area, with six traps baited with human excrement and six with rotten liver. Fifteen species and 1298 specimens were collected in the Forest and 25 species and 2235 specimens in the Tabuleiro. Eleven species occurred in both areas, whereas 14 were found only in the Tabuleiro and four in the Forest. Dichotomius sericeus (Harold, 1867) was the most abundant species in the two areas. The Tabuleiro was the most species-rich; however dominance was greatest in the Forest. The presence of common species in the two studied areas confers a moderate similarity to the forest and Tabuleiro habitats.
Os Scarabaeidae consomem fezes e carcaças de grandes vertebrados. Comunidades de escarabeídeos foram comparadas entre áreas de Mata e Tabuleiro da Reserva Biológica Guaribas, Mamanguape, Paraíba. As amostragens foram realizadas mensalmente durante o período de Novembro/2001 a Abril/2002 em áreas de Tabuleiro e Mata. Para coleta dos insetos foram utilizadas 24 armadilhas pitfall iscadas, 12 em cada área, sendo seis iscadas com fezes humanas e seis com fígado apodrecido. Na área de Mata foram coletados 15 espécies e 1298 indivíduos. Na área de Tabuleiro, 25 espécies e 2235 indivíduos. Onze espécies ocorrem conjuntamente nos dois ambientes, sendo 14 registradas apenas para o Tabuleiro e 4 para a Mata. Dichotomius sericeus (Harold, 1867) foi a espécie mais abundante nas duas áreas. A área de Tabuleiro apresentou maior riqueza, entretanto a Mata apresentou maior dominância. O compartilhamento de espécies comuns entre a Mata e o Tabuleiro confere a estes ambientes similaridade moderada.
Subject(s)
Animals , Coleoptera , Biodiversity , Brazil , EcologyABSTRACT
Este estudo objetivou levantar preliminarmente os escarabeíneos copro-necrófagos da região de Brejo Novo, Caruaru, Pernambuco, e verificar aspectos da estrutura da comunidade como sazonalidade, diversidade, equitabilidade, riqueza e abundância das espécies. Foram realizadas 10 coletas, com intervalos de 30 dias e duração de 48 horas, de setembro de 2003 a julho de 2004. Utilizaramse 24 armadilhas de queda, com dois tipos de isca, fezes humanas e carne bovina em estado de putrefação. Foram coletados 1.540 indivíduos pertencentes a seis tribos, 12 gêneros e 28 espécies. As espécies Canthon af. carbonarius, Canthon chalybaeus, Dichotomius nisus, D. semisquamosus, Digitonthophagus gazella e Eurysternus hirtellus aparentemente são as mais adaptadas ao ambiente estudado. Foram coletados 826 indivíduos em armadilhas iscadas com fezes humanas e 714 em carne bovina apodrecida. Ocorreu um número maior de espécies consideradas "raras" (15), sendo três destas "singletons", duas "doubletons" e 10 com abundância entre três e 10 indivíduos, 13 espécies foram consideradas "comuns". Das espécies analisadas, sete apresentaram hábitos alimentares generalistas, quatro são estritamente coprófagas e uma estritamente necrófaga. Foram verificadas correlações positivas entre a precipitação mensal e a abundância e a riqueza de espécies. O levantamento preliminar das espécies de Scarabaeinae da região de Brejo Novo contribuiu para aumentar o número de espécies registradas para o estado de Pernambuco e região Nordeste do Brasil.
This paper reports the results of the preliminary survey of copro-necrophagous dung beetles of Brejo Novo region, Caruaru, Pernambuco, as well as some aspects of the community structure such as seasonality, diversity, equitability, richness and abundance of species. Ten samplings with intervals of 30 days and duration of 48 hours, fortnightly were done between September 2003 to July 2004. Scarab beetles were collected with 24 pitfall traps baited with two types of baits, human excrements and rotting bovine meat. A total of 1,540 individuals belonging to six tribes, 12 genera and 28 species were collected. The species Canthon af. carbonarius, Canthon chalybaeus, Dichotomius nisus, D. semisquamosus, Digitonthophagus gazella and Eurysternus hirtellus are, apparently, adapted to the studied environment. Traps baited with human excrements attracted 826 individuals and those with rotting bovine meat attracted 714 specimens. Large number of species (15) considered "rare" occurred, being three of them "singletons", two "doubletons" and 10 with abundance between three and 10 individuals; 13 species were considered "common". Of the analyzed species, seven present generalist alimentary habits, four are strictly coprophagous and one is strictly necrophagous. Positive correlations were verified between the precipitation and the abundance of the individuals and the species richness. This preliminary survey of the dung beetles of the Brejo Novo region contributed to increase the number of species registered for Pernambuco and northeast region of Brazil.
Subject(s)
Animals , Male , Female , Coleoptera , Biodiversity , Brazil , Ecology , Ecosystem , WetlandsABSTRACT
Os insetos da família Scarabaeidae se alimentam da matéria orgânica em decomposicão, participando ativamente da ciclagem de nutrientes. C. ensifer é um necrófago de grande porte que ocorre em áreas de florestas tropicais. Este estudo teve por objetivo conhecer o padrão sazonal da espécie neste ambiente e avaliar a atratividade das iscas utilizadas. Foram realizadas 13 coletas entre os meses de Dezembro/98 e Dezembro/99 na Mata do Buraquinho, um remanescente de Mata Atlântica em João Pessoa, PB. Foram coletados 71 espécimes usando armadilhas com quatro tipos de isca: 35 em carne de porco, 22 em rim bovino e 14 indivíduos em carne bovina, não havendo diferencas significativas entre as iscas em relacão a sua atratividade para com os insetos. Não foi coletado nenhum espécime em fígado bovino. A abundância mensal esteve diretamente correlacionada com a precipitacão (r s=0,65; p<0,05) e com a umidade (r s=0,55; p<0,05) e inversamente com a temperatura (r s=-0,70; p<0,01). Os espécimes somente foram coletados entre os meses de Abril a Setembro, coincidindo com o período chuvoso na região, o que corrobora o padrão sazonal da espécie.