My work has focused on three groups: a group of parasitoid wasps, Sierola (Hymenoptera: Bethylidae); the pomace flies, Drosophila (Diptera: Drosophilidae); and the only native bees, Hylaeus (Nesoprosopis) (Hymenoptera: Colletidae). Each of these are globally significant, making up 10-30% of the world’s species in their respective families, but they each face different challenges for survival in a changing world of invasive species and climate change.
Flat wasps: Sierola
Referred to as “Hawai‘i’s forgotten megaradiation”, Sierola is a striking example of island evolution. The genus occurs throughout the Indo-Pacific and Australia and is the largest in the family Bethylidae, but the Hawaiian species make up over 90% of the total, with probably 400 or more endemics. O‘ahu alone has an astonishing 158 species, nearly all island endemics. It has been largely ignored since the previous monograph in 1920. The currently described species are heavily biased towards the islands of O‘ahu and Hawai‘i; the other islands probably have similar numbers of species but only a few are recorded. For example, only six species are described from Kaua‘i, but I have collected over 70 in just a few trips. Most species occur as rare, scattered individuals, meaning that the bulk of specimens belong to just a few species and sustained, repeated collecting is required to obtain a good sample.
Pomace flies: Drosophila
The largest radiation of native insects, Drosophila are also among the best known. This is largely due to the extensive studies that have been conducted on the charismatic “picture wing” species, which include the largest Drosophila in the world. Some Hawaiian Drosophila may be ten times the size of the familiar Drosophila melanogaster used in genetics labs. But there are hundreds more species that are smaller and less conspicuous, and new species are found every day. There is currently a backlog of at least 100 species that have been collected but not yet described.
Yellow-faced bees: Hylaeus (Nesoprosopis)
Hawai‘i has only one group of native bees, and their origin is remarkable. Sweat bees and leafcutter bees are widespread in the South Pacific, but neither group made it to Hawai‘i. Meanwhile, yellow-faced bees are found on no other remote oceanic islands and are a relatively minor component of the continental bee fauna (aside from Australia), yet they managed to reach Hawai‘i and evolve into more species than are found in all of North America. Called “almost the most ubiquitous of all Hawaiian insects” by famed early entomologist R.C.L. Perkins, they have been seriously impacted by invasive ants and yellowjackets, loss of native plants, and climate change, and many species are endangered.