Resource partitioning in the carrion beetle (Coleoptera:Silphidae) fauna of southern Ontario: ecological and evolutionary considerations

Abstract

Resource partitioning in the silphid fauna of southern Ontario is examined in detail, using baited pitfall traps placed in four different habitats. During 1979 and 1980, a total of 9549 specimens of Silphidae were collected, representing 12 species, of which 5 were in the subfamily Silphinae and 7 in the subfamily Nicrophorinae. The roles of different seasonal patterns, habitat specificity, and food type and size in resource partitioning are discussed for all species. At the subfamilial level, resource partitioning is accomplished through selection of different sizes of carcasses, while at the specific level, seasonal patterns and habitat specificity appear to be the primary means permitting coexistence.In the Silphidae, competition for food resources appears to be the primary factor inducing ecological character displacement. The possible origins of patterns of resource use in this assemblage are discussed in an ecological and geological time framework.

Relative Abundance of Nicrophorus Pustulatus (Coleoptera: Silphidae) in a Burying Beetle Community, With Notes on its Reproductive Behavior

“…The relative abundances and seasonal distributions I found are consistent with similar studies of burying beetle communities in southern Ontario (Anderson, 1982), Michigan (Wilson et al, 1984), and North Carolina (Trumbo, 1990a). N. pustulatus were rarely captured in June and July, and were never captured in August.…”

“…N. pustulatus were rarely captured in June and July, and were never captured in August. N. defodiens and N. sayi were also rare, but this is likely because their peak activity period is in May and early June (Anderson, 1982). N. orbicollis and N. tomentosus were abundant during their respective breeding seasons, which for N. orbicollis ranged from June to July, and for N. tomentosus began in August (unpublished data;Scott and Traniello, 1990).…”

“…According to Anderson (1982), N. pustulatus are associated with all types of forest habitat, but they are rare in meadows and absent from marshes. Because my study site was primarily mixeddeciduous forest, my inability to capture many N. pustulatus probably does not reflect a lack of suitable habitat.…”

“…Anomalies in this species' behavior suggest that its life history is different from that of its congeners. Unlike other Nicrophorus species, N. pustulatus are only infrequently collected in traps baited with carrion, and they are more commonly captured at lights (Anderson, 1982;. Furthermore, Wilson et al (1984) and Trumbo (1990a) report that N. pustulatus were never attracted to 15-40 g dead mice placed in the field, whereas congeners such as N. orbicollis were among the first scavengers to arrive at those carcasses.…”

Les larves de diptères nécrophages en entomologie médico-légale : une histoire de température

“…Afin d'optimiser cette datation du décès, les recherches actuelles portent sur les paramètres qui influent sur le développement des larves de diptères nécrophages, notamment la température. Beaucoup d'études se sont en effet intéressées à la biologie [11], à l'écologie [12], à la physiologie [13] ou encore au comportement des larves des insectes nécrophages [14]. Ces études ont apporté un grand nombre de données désormais prises en considération pour les expertises médico-légales.…”