The Crater District of Haleakala National Park was surveyed for
ants. Three species were found. Argentine ants (Iridomyrmex humilis) occurred
only within I km of the park headquarters and the nearby research facility.
Hypoponera opaciceps was found in small numbers throughout the Crater
District. Cardiocondyla emeryi was present only at the head of Kaupo Gap.
Possible impacts of these ant species on the endemic, flightless insects of the park
are discussed