Seasonal abundance and sexual variation in morphometric traits of Oxelytrum discicolle (Brulle, 1840) (Coleoptera: Silphidae) in a Brazilian Atlantic Forest

Abstract

Ferreira, P.S.F.; Pires, E.M.; Guedes, R;N.C.; Mendes, M. and Coelho, L.A. Seasonal abundance and sexual variation in morphometric traits of Oxelytrum discicolle (Brulle, 1840) (Coleoptera: Silphidae) in a Brazilian Atlantic Forest.A total of 293 specimens of Oxelytrum discicolle were sampled weekly over a period of two years using a black light trap. The study took place in an Atlantic Forest reserve located near Viçosa city, Minas Gerais State, Brazil. The period of peak abundance of O. discicolle occurred during the wet season between the months of October and March. Statistical analysis showed that the abundance of individuals was significantly and positively correlated with temperature, but not with rainfall or relative humidity. Of 28 morphological measurements taken on each collected specimen, seven were found to be sexually dimorphic; however, neither morphology nor the degree of sexual dimorphism varied significantly among seasons. ResumoFerreira, P.S.F.; Pires, E.M.; Guedes, R;N.C.; Mendes, M. and Coelho, L.A. Abundância sazonal e variação morfométrica nos caracteres sexuais de Oxelytrum discicolle (Brulle, 1840) (Coleoptera: Silphidae) em uma floresta Atlântica brasileira.Um total de 293 espécimes de Oxelytrum discicolle foram amostrados semanalmente num período de dois anos usando uma armadilha tipo "black light". O estudo foi feito em uma reserva de Mata Atlântica localizada próximo à cidade de Viçosa, Minas Gerais, Brasil. O período de pico de abundância de O. discicolle ocorreu durante a estação úmida, entre os meses de outubro e março. A análise estatística mostrou que a abundância dos indivíduos foi significantemente e positivamente correlacionada com a temperatura, mas não com a precipitação e umidade relativa. De 28 características morfológicas tomadas em cada espécime coletado, sete foram encontradas sexualmente dimórficas, entretanto, nem morfologia nem o grau de dimorfismo sexual variaram significantemente entre as estações. Palavras-chave: Oxelytrum discicolle, dinâmica populacional, dimorfismo sexual, Minas GeraisBiota Neotropica v6 (n2) -http://www.biotaneotropica.org.br/v6n2/pt/abstract?article+bn02206022006

Seasonal and interpopulational morphometry variation of Platyscytus decempunctatus (Carvalho 1945) (Heteroptera: Miridae)

“…Such finding was also previously reported for morphological studies with others species like Triatoma dimidiata (Heteroptera: Reduviidae) (Lehmann et al 2005), Podisus mucronatus (Heteroptera: Pentatomidae) (Costello et al 2002), Oxelytrum discicolle (Coleoptera: Silphidae) (Ferreira et al 2006), Oncideres dejeani (Coleoptera: Cerambycidae) (Seffrin et al 2006 Males of P. decempunctatus showed only two body traits larger than the females: antennal length and 2 nd antennal segment length. Males usually have larger antennae than females because they have more sensory sensilla related to their increased capacity of locating females for mating (Chapman 1998).…”

“…The dissimilarity indexes thus calculated were subsequently correlated with geographical distance between each pair of sampling sites (PROC CORR, SAS Institute 2001). The geographical distances (km) between sampling sites were obtained through a global positioning system (Ferraz 1980).…”

“…Morphometry studies are currently playing a major role in various fields of the entomology, like in the description of new species (Bernardes et al 2006, Ferreira & Coelho 2006 and immature stages (Grazia & Frey-da-Silva 2001, Prezoto & Gobbi 2005, Silva et al 2006, Smith 1979, in distinction between some species (Santos et al 2003), in comparative studies of internal morphological structures (Lemos et al 2001), in studies with asymmetry and developmental stability (Garnier et al 2006), in recognizing seasonal influence on species morphology (Ferreira et al 2006), and in distinguishing sexual-related traits in male and female insects (Carlessi et al 1999, Ferreira et al 2006. The objective of this research was to recognize morphometrical differences in P. decempunctatus of both sexes collected during the dry and wet seasons in Viçosa, MG and to verify the similarity among populations.…”

Entomofauna resource distribution associated with pig cadavers in Bogotá DC

“…Depredation of the most mature larval forms might be considered as a tactic for consuming the greatest amount of food with the least effort. In such conditions, adult Coleoptera make best use of the great abundance of Diptera larvae for food, whilst larval forms of the same species feed directly on the cadaver in its subsequent stage of decomposition; this strategy for differentiating resources was described by Reed in 1958 (cited by Ferreira et al , 2006).…”

Morphometry of Cornops aquaticum(Orthoptera: Acrididae: Leptysminae) in the Pantanal of Mato Grosso, Brazil

“…Assessing the morphometric characteristics of insects has been very useful in population studies, in terms of communities, and is used for the identification of nymph stages, features of sexual dimorphism (Zolessi, 1956;Turk and Barrera, 1976;Cepeda-Pizarro et al, 2003;Domenico, 2005;Cherril, 2005;Franceschini et al, 2005;Ferreira et al, 2006;Seffrin et al, 2006), life history and evolution with host plants (Klingenberg and Spence, 1997;Ahnesjö and Forsman, 2003;Adis et al, 2008), as well as ecological studies of populations and communities (Dirsh, 1953;Roonwal, 1981;Filin and Ovadia 2007;Pires et al, 2008).…”