Reintroduction of a Native Hawaiian Bee, Hylaeus anthracinus (F. Smith) (Hymenoptera: Colletidae), to Part of its Former Range

Abstract

The endangered endemic coastal bee Hylaeus anthracinus (F. Smith) (Colletidae) is currently restricted to a few populations on each island from Oahu to Hawaii, which are mostly near the shoreline and vulnerable to extirpation due to environmental change or alien species incursion. At the same time, the species is absent from some sites where it formerly occurred that have once again become suitable due to habitat restoration. To increase the number of populations and test translocation as a method for Hylaeus conservation, bees were captured at highdensity sites in South Kohala, Hawaii island and released at three sites in South Kona at Puuhonua o Honaunau National Historic Park. Follow-up monitoring indicated that they successfully established at the highest-quality site with a diverse array of native plants following a single release of 100 bees, but failed to survive at two sites with high abundance of bigheaded ants (Pheidole megacephala) even after a second release. This study may serve as a model for re-establishing not only Hylaeus but other native insects that have been lost from large parts of their range.