Pan trapping in habitats supporting Platanthera (Orchidaceae) shows little difference in insect family-level diversity

Abstract

The role of insects as pollinators within plant communities is well established, yet our knowledge of insect biodiversity in many habitats is lacking. Given the growing concern that insect biodiversity is declining, it is increasingly important to document insect assemblages from a wide range of geographic locations and habitats. Pan trapping is a common means of sampling local insect diversity. Many studies have found different insects associated with different-coloured pan traps. Here, eight different-coloured pan traps were used to sample local insect diversity in habitats supporting <i>Platanthera</i> (bog and rein) orchids on Vancouver Island, British Columbia, Canada. A total of 16 sites supporting seven orchid species resulted in 435 insects from 53 families being caught over 64.9 hours of pan trapping. Both Shannon and Simpson diversity index values were low despite sampling in markedly different habitats. Yellow traps caught higher numbers of insects, but no statistical difference was found among colours overall. No activity indicating pollination was recorded from a total of 254 insect observations over 21.5 hours. Our results contribute important baseline data on the diversity and behaviour of insect communities in orchid habitats of Vancouver Island and on the use of pan traps to characterise insect communities.