Life history traits of five ground beetle (Coleoptera: Carabidae) species common in Honshu Island, Japan

Abstract

Ground beetles have been used as bioindicators for monitoring environmental changes. However, to interpret monitoring results, we need further information on their life history traits. We selected Harpalus griseus, H. eous, H. tridens, Synuchus cycloderus and Carabus procerulus, species common in Honshu Island, Japan. We examined their hind wings, flight muscles, gut contents and ovarian eggs to understand their flight activity, feeding traits and reproductive strategies. The three Harpalus species showed wing length / body length ratios (W/B) of 0.88 - 0.99. In H. tridens, the proportion of individuals with flight muscles and caught in aerial traps was lower than in the other two. S. cycloderus was macropterous with a W/B ratio of 0.75, but no individuals were caught in aerial traps, and none possessed flight muscles. C. procerulus was brachypterous. The three Harpalus species fed mainly on seeds and partly on arthropods. S. cycloderus was a generalist predator. Gut contents of C. procerulus consisted of amorphous fluid, suggesting extra-oral digestion. Egg type was categorized by the number and size of ovarian eggs. S. cycloderus had many-small eggs, while the other four had few but large eggs.

Examining the bias of pitfall traps with enclosure experiments and removal sampling

“…Silphid species (Silpha perforata) are categorised as forest species according to Katakura et al (1986). Pterostichus microcephalus is a wing polymorphic species (Shibuya et al, 2018), but most of the individuals we captured were brachypterous (only 2 of 18 individuals were macropterous). Thus, P. microcephalus was included in the analysis.…”

“…In this study, we categorised each species as a macropterous, apterous, or brachypterous species by checking their wing types according to Shibuya et al (2018) and used only apterous and brachypterous species (species having no, very short, or rudimentary wings) in the analysis. This is because our fences had no roof, and we could not exclude the possibility of movement of individuals in species that can fly over fences.…”