Nest ecology of an endemic Hawaiian bee, Hylaeus anthracinus (Hymenoptera: Colletidae), and implications for conservation Jason R. Graham 1 , Sheldon Plentovich 2 , and Cynthia B. A. King 3 1 University of Hawaiʻi at Mānoa, College of Tropical Agriculture and Human Resources, Department of Plant and Environmental Protection Sciences 2 United States Fish and Wildlife Service, Pacific Islands Coastal Program 3 Hawaiʻi Department of Land and Natural Resources, Division of Forestry and Wildlife Hylaeus anthracinus (Hymenoptera: Colletidae) is an endemic Hawaiian bee and candidate for federal protection as an endangered species. On Oahu, H. anthracinus populations are restricted to a few isolated populations in fragments of endangered coastal strand habitat. Prior to this study, knowledge of H. anthracinus natural history was based largely on observations from closely related bees, but little was known regarding the specific nest ecology, or immature development needed to design effective and sustainable conservation management methodologies. Objective: Our goal was to gather specific details surrounding the nest ecology and natural history of H. anthracinus, in order to develop and apply conservation management methodologies to increase the populations of this candidate endangered species. A B A Turtle Bay B Sandy Beach Activity level of two Hylaeus anthracinus populations measured as average landings per minute during timed point counts at Turtle Bay or Sandy Beach field sites from Dec 2014-Jan 2016. Hylaeus anthracinus mating Endangered coastal strand habitat Some females nest in coral rubble Others nest in hollow plant stems Oahu, Hawaii
Transcript
Nest ecology of an endemic Hawaiian bee, Hylaeus anthracinus (Hymenoptera: Colletidae), and implications for conservation
Jason R. Graham1, Sheldon Plentovich2, and Cynthia B. A. King3
1University of Hawaiʻi at Mānoa, College of Tropical Agriculture and Human Resources, Department of Plant and Environmental Protection Sciences2United States Fish and Wildlife Service, Pacific Islands Coastal Program
3Hawaiʻi Department of Land and Natural Resources, Division of Forestry and Wildlife
Hylaeus anthracinus (Hymenoptera: Colletidae) is an endemic Hawaiian bee and candidate for federal protection as an endangered species. On Oahu, H. anthracinus populations are restricted to a few isolated populations in fragments of endangered coastal strand habitat. Prior to this study, knowledge of H. anthracinus natural history was based largely on observations from closely related bees, but little was known regarding the specific nest ecology, or immature development needed to design effective and sustainable conservation management methodologies.
Objective: Our goal was to gather specific details surrounding the nest ecology and natural history of H. anthracinus, in order to develop and apply conservation management methodologies to increase the populations of this candidate endangered species.
A
BA Turtle Bay B Sandy Beach
Activity level of two Hylaeus anthracinus populations measured as average landings per minute during timed point counts at Turtle Bay or Sandy Beach field sites from Dec 2014-Jan 2016.
Hylaeus anthracinus mating
Endangered coastal strand habitat
Some females nest in coral rubble
Others nest in hollow plant stems
Oahu, Hawaii
B
A
C
D
A B DC
Acknowledgements: This project was funded by the Department of Defense Legacy Resource Management Program. We thank Karl Magnacca and Kapua Kawelo of the O‘ahu Army Natural Resources Program; Joseph Schwagerl and Kenzie Jackson Letchworth of US Fish &Wildlife Service National Wildlife Refuge; William Haines of the University of Hawaiʻi at Mānoa for support and assistance in carrying out work for this project.
Potential risks to H. anthracinus were observed during this study including: non-native bees as nest competitors; human activities; climatic events; pests/predators; and bee pathogens.
Contact Information:Jason R. Graham, PhDUniversity of Hawaiʻi at Mā[email protected](352) 519-9592
Approach: We monitored study sites to determine Hylaeus population size, activity level, community structure, and use of resources. Populations were measured as timed point counts of bee landings within site. We collected materials suspected of containing nests for dissection, measured the dissected nest parameters, and described the architecture. We transferred developing immature bees into queen cups using grafting tools and observed development on a daily basis. The data and insights we gathered in this study facilitated the design of artificial nest sites now being tested as conservation management tools.
Immature bees were reared to adult in order to describe the development of these bees, and verify the species corresponding to each dissected nest. Eggs developed to adults in ≥29 days.
Hylaeus anthracinus utilize the coastal plants Scaevola sericea (left) and Heliotropium foertherianum (right) for both forage and nest resources.
Outcome: Nest dissections provided an understanding of the natural nest architecture and ecology of native Hylaeus. These data guided the development of artificial nest sites, that have been accepted by H. anthracinus in field trials. Artificial nest sites can potentially strengthen weak native bee populations, repopulate high priority managed areas, and exclude ants and other crawling pests and predators.
