Mauna Kea's Wekiu Bug
From the Hawaiian Volcano Observatory:
Hawaiian word for top or summit. This
name was given to Mauna Kea's tallest cinder cone, which
reaches 13,796 feet in elevation and is the highest in the
Hawaiian archipelago. Life on the Mauna Kea summit must
endure freezing temperatures, winter snow falls, and,
occasionally, hurricane-force winds. The centers of the
summit cones on Mauna Kea are permanently frozen to just
a few feet below the surface. Only lichens and some
mosses grow scattered on the tops of rocks. Until recently
these cold stone fields were thought to be devoid of
resident animal life.
bug was first discovered in 1980 by
biologists searching for insects under stones on Pu`u
Wekiu. Although known to scientists as Nysius wekiuicola,
this "seed bug" in the family Lygaeidae was given the
common name "wekiu bug" to highlight the unusual location
where these insects live. As their familiar name implies,
most seed bugs feed on seeds by piercing their straw-like
mouth parts into the inner seed tissue and sucking it out.
However, since no native seed-bearing plants live in the
summit area of Mauna Kea, it was clear to biologists that
these insects must be tapping into a different food source
than their close relatives.
studied the ecology of the wekiu bug to find
out how it could survive in such an extreme and hostile
environment. Unlike their seed-feeding relatives, the wekiu
bugs consume other dead and dying insects that get carried
upslope by winds and deposited at the summit. The bugs
search under rocks and across ash flows for fresh,
wind-blown carcasses. They then use their piercing
mouth-parts to puncture the exoskeleton of their prey and
suck out the juices inside.
nearly one quarter of an inch long with
long, thin legs. Young bugs are dark brown with red
abdomens, while the adult bugs are a more uniform dark
brown to black color. Like all other true bugs, the young
have only small developing wing pads. The adults,
however, never develop full wings. Having extremely
reduced wings may be an advantage to an insect that sneaks
its way through rocks and ash. Besides, flying at the summit
of Mauna Kea can send a bug on a long trip.
their summit home with other arthropods,
including spiders and caterpillars. Each has found its own
way of dealing with the extreme cold found at this
elevation. Wolf spiders hunker down under rocks that have
been absorbing the sun's heat during the day. Moth
caterpillars, like many other types of insects, have a sort of
antifreeze in their bodies that prevents ice crystals from
forming in their cells. The wekiu bug also can endure
subfreezing temperatures with a natural antifreeze in its blood
but also has a dark body to absorb warmth from the sun and
simultaneously protect it from ultraviolet radiation.
the wekiu bug was known only from the three
cones at the summit of Mauna Kea. Construction of
observatories at the summit of Mauna Kea raised concerns
that the wekiu bug may be in jeopardy of losing its only
known habitat. So the search began to find more bugs on
Mauna Kea and the slopes of Mauna Loa. Individuals have
now been observed on cinder cones nearly three miles from
the Mauna Kea summit, while a previously unknown
species was discovered on Mauna Loa.
The Mauna Loa
bug, Nysius aa, was first captured in 1985
but not described as a different species until 1998. The life
style of this bug appears to be very similar to that of its
sister species, the wekiu bug, but subtle differences in its
appearance make it clear that this is not the same species.
Similar species have not been observed from Hualalai or
Haleakala, but maybe they just haven't been found yet."