Pollinator trapping in selfing carnivorous plants, Drosera makinoi and D. toyoakensis (Droseraceae)

Abstract

AbstractCarnivorous plants use insects not only as prey, but also as pollinators. Whereas outcrossing carnivorous plants are known to avoid trapping pollinators, selfing carnivorous plants may capture the pollinators as prey. Here, we provide evidence that two selfing carnivorous plant species with short flower‐trap separation, Drosera makinoi (white‐colored flowers) and D. toyoakensis (pink‐colored flowers), caught some major pollinator species belonging to Diptera and Hymenoptera: four out of five species in D. makinoi and one out of six species in D. toyoakensis. We also tested the function of flowers to attract pollinator or prey insects by experimentally removing Drosera flowers. Flower removal did not significantly affect the number of trapped insects. On the other hand, the removal of flowers of co‐flowering neighbor plants, Eriocaulon decemflorum for D. makinoi and Lysimachia fortunei for D. toyoakensis, significantly decreased the number of trapped insects. This finding suggests an exploitative relationship between Drosera spp. and co‐flowering species.