Yellow faced bees: Hylaeus finitimus
(Hymenoptera: [Apoidea:] Colletidae: Hylaeinae)
Profile prepared by Karl Magnacca, USGS-BRD, Kilauea Field Station
Hylaeus finitimus is a coastal bee endemic to the island of Kauai in Hawaii. It is closely related to H. longiceps of Oahu and Maui Nui. The species is known only from two specimens, one of which is lost, and may be extinct.
Xerces Red List Status: Critically Imperiled (Possibly Extinct)
Canada – Species at Risk Act: N/A
Canada – provincia l status: N/A
USA – Endangered Species Act: None
USA – state status: None
IUCN Red List: N/A
This species is extremely rare and may be extinct. It is known from only two specimens collected over 100 years ago. U.S. Federal listings of rare and endangered species classed H. finitimus as a “Category 3A” Candidate Species, considered “probably extinct”. It currently has no status as a “Species of Concern” at the federal or state level.
Males: Black; face yellow below the antennae, extending along the inner margin of the eye.
Females: Black, unmarked; indistinguishable from H. longiceps. Hylaeus finitimus is a somewhat enigmatic species. Perkins’ (1899) original description and later key (Perkins, 1910) conflict in the characters that supposedly distinguish it from H. longiceps, and the type male is lost.
Hylaeus finitimus was described as Nesoprosopis finitima by Perkins (1899). Nesoprosopis was reduced to a subgenus of Hylaeus by Meade-Waldo (1923). The most recent taxonomic treatment was Daly and Magnacca (2003). The lack of definitive characters separating it from H. longiceps suggests it may be a variety of that species.
Hylaeus finitimus inhabits coastal strand. It probably nests in the ground like related species. Nothing more is known about it.
Hylaeus finitimus has been collected from the southern coast of Kauai.
The rarity of H. finitimus and lack of knowledge about its requirements make it difficult to assess threats. Coastal habitat has been heavily impacted by development and invasive plants. Its sister species, H. longiceps, is widespread and found abundantly wherever suitable coastal habitat exists. However, a large area of good coastal habitat remains at Polihale and Barking Sands, and H. finitimus has not been collected there. Other potential sites for this species exist but have not been investigated.
The top priority is to identify extant populations and document the continued existence of the species. The coastal site at Polihale and Barking Sands is protected by the State of Hawaii and the U.S. Air Force, but faces continued impacts from visitors and military activities. Other sites are not protected and may be destroyed by development. Research is needed in order to locate extant populations and determine reasons for rarity.
Daly, H. V., and K. N. Magnacca. 2003. Insects of Hawaii, Vol. 17: Hawaiian Hylaeus (Nesoprosopis) Bees (Hymenoptera: Apoidea). University of Hawaii Press, Honolulu. 234 pp.
Meade-Waldo, G. 1923. Hymenoptera, fam. Apidae, subfam. Prosopidae, fasc. 181. Pp. 1-45 in P. Wytsman (ed.), Genera Insectorum. L. Desmet-Verteneuil, Brussels.
Perkins, R. C. L. 1899. Hymenoptera, Aculeata. Pp. 1-115 in D. Sharp (ed.), Fauna Hawaiiensis, Vol. 1. Cambridge University Press, Cambridge, United Kingdom.
Bishop Museum Extinct Species – Insects Lists H. finitimus as extinct. Updated March 21, 2002.
Magnacca, K. N. 2005. Species Profile: Hylaeus finitimus. In Shepherd, M. D., D. M. Vaughan, and S. H. Black (Eds). Red List of Pollinator Insects of North America. CD-ROM Version 1 (May 2005). Portland, OR: The Xerces Society for Invertebrate Conservation.