Drosophila heteroneura

[sebbe67]

Drosophila heteroneura has been recorded from 24 localities on 4 of the island’s
5 volcanoes (Hualalai, Mauna Kea, Mauna Loa, and Kilauea) in 5 different mesic to wet
montane environments (Kaneshiro and Kaneshiro 1995; K. Kaneshiro, in litt. 2005a).
Based on the relatively extensive survey data, the population decline of Drosophila
heteroneura has been demonstrated clearly. For example, D. heteroneura was recorded
760 times during surveys between 1975 and 1979. In the early 1980s, the first
disappearance of a D. heteroneura population was recorded from the Olaa Forest site in
Hawaii Volcanoes National Park (Carson 1986; Foote and Carson 1995). Subsequently,
the absence of the species was noted in several other locations in southern and western
parts of the island where D. heteroneura had previously been relatively common. By the
late 1980s, D. heteroneura was believed to be extinct until an extremely small population
was discovered on private land at Hualalai Volcano in 1993 (Kaneshiro and Kaneshiro
1995). The species was not observed again until 1998 when Foote (2000) recorded six
specimens of D. heteroneura inhabiting a site at approximately 1,352 meters (4,436 feet)
above sea level near a host plant species, Clermontia clermontioides. Drosphila
heteroneura was last observed in 2001 at the Kona Unit of the Hakalau Forest National
Wildlife Refuge (D. Foote, U.S. Geological Survey, in litt. 2005).

[Melanie]

Drosophila heteroneura

R.C.L. Perkins described Idiomyia heteroneura, based on specimens
from `Ola`a on Hawai`i island (Perkins 1910). This taxon was later
transferred to the genus Drosophila (Hardy 1969), forming its presently
accepted name, D. heteroneura. Drosophila heteroneura has very large
spots on the bases of the wings. However, the most characteristic
feature of this species is the broad head of the male with the eyes
situated laterally, thus giving it a hammer-head appearance. The
hammer-head and entirely yellow face differentiate it from the closely
related species, D. silvestris. The thorax is predominantly yellow with
several black streaks and markings on top. The legs are yellow except
for slight tinges of brown on the ends of the middle and hind femora
and tibiae. The wings are hyaline (transparent) and are very similar in
markings and venation to those of D. silvestris, except that the
marking in the front margin of the wing of D. heteroneura extends
nearly to the marking at the end of the wing. The abdomen is shining
black with a large yellow spot on the top of each segment. This species
is about 5.7 mm (0.22 in.) in length with wings approximately 7.0 mm
(0.3 in.) long.
Drosophila heteroneura is restricted to the island of Hawai`i where
it was historically known from 16 localities, on 4 of the island's 5
volcanoes (Hualalai, Mauna Kea, Mauna Loa, and Kilauea). This species
has never been found on the Kohala Mountains. The species was believed
to be extinct in the late 1980s, until it was rediscovered on private
acreage at Hualalai Volcano in 1993. The remaining population is
extremely small, with a 90 percent reduction from historical abundance
(Kaneshiro and Kaneshiro 1995).
Drosophila heteroneura breeds primarily in the bark and stems of
Clermontia spp. and Delissea spp., but it is also known to utilize
Cheirodendron spp. in open rain forest habitat. This Hawaiian picture-
wing is endangered by habitat degradation from ungulates and alien
weeds, predation by ants and alien wasps, and an extremely small
remaining population.

www.epa.gov/EPA-SPECIES/2001/January/Day-17/e1338.htm

[surroundx]

Foote, D. (1999). Rediscovery of Drosophila heteroneura on the Island of Hawai'i. Bishop Museum Occasional Papers 64: 27-28.

[koeiyabe]

“Extinct & Endangered: Insects in Peril” by AMERICAN MUSEUM OF NATURAL HISTORY (2022)