Host-use patterns of canopy-inhabiting click beetles (Coleoptera: Elateridae) in a lowland rainforest in southern Venezuela

Abstract

The arboreal click beetle fauna (Coleoptera: Elateridae) in a lowland tropical rainforest in southern Venezuela was observed and collected by means of a tower crane for a full year. The evaluation of the elaterid assemblage is part of a general survey of Coleoptera associated with several canopy trees. The Elateridae represented the tenth most species-rich beetle family in the canopy of the crane plot and was therefore selected for a detailed analysis of host-use patterns. In total, 20 species of Elateridae with 402 adult individuals were sampled, including seven singletons. Species were either flower visiting (Aeolus Eschscholtz and Cosmesus Candèze) or fed mainly on extrafloral nectaries (Chalcolepidius Eschscholtz, Crepidius Candèze, Lacon Castelnau, Lissomus Dalman, and Semiotus Eschscholtz). The most abundant species was Aeolus sp. 1 (N = 306) feeding on flowers of nine different host-tree species. This species was found often in high abundances during the entire flowering period of a single tree species with highest abundances coinciding with the maximum of open flowers. Aeolus sp. 1 was recorded almost every month of the year moving usually from one flowering tree species to another comprising possibly the entire local population. This species showed preferences between different tree species and occurred there only at night. Tree species that supported the most species-rich elaterid assemblages were Ruizterania trichanthera (Spruce ex Warm.) Marc.-Berti (Vochysiaceae) (N = 8) and Goupia glabra Aubl. (Goupiaceae) (N = 6). Only one elaterid species with at least two collected individuals was found restricted to one tree species.