Sap beetles (Coleoptera: Nitidulidae) in managed and old-growth forests in southeastern Ontario, Canada

Abstract

AbstractNitidulid beetles were sampled from old-growth and mature managed hemlock-hardwood forest stands in southeastern Ontario, Canada. Large-area flight-intercept traps and trunk-window traps were operated for 22 weeks in 2003 and yielded 2129 nitidulid beetles representing 30 species. Species richness was similar in both forest types but relative abundance was higher in managed stands. Other diversity measures (rarefaction-estimated species richness, Fisher's α, Simpson's index) were all higher in old-growth stands, and managed stands were separated from old-growth stands in cluster analyses based on overall species diversity. These results were strongly influenced by the dominance of Glischrochilus quadrisignatus (Say) in two managed stands; removal of that species from analyses resulted in higher species diversity in managed stands and no distinct separation of forest types in cluster analyses. Indicator species analysis showed that G. quadrisignatus and Pallodes pallidus (Palisot de Beauvois) were strongly associated with managed stands. Glischrochilus sanguinolentus (Olivier) was collected more frequently in trunk-window traps than in flight-intercept traps and data suggested a possible association of this beetle with old-growth stands. Pallodes pallidus and Cychramus adustus Erichson, both known to feed on fleshy white fungi, displayed a clear division in seasonal abundance peaks, suggesting that resource partitioning may be occurring.