Content area
Full Text
J Insect Conserv (2010) 14:701709 DOI 10.1007/s10841-010-9298-y
ORIGINAL PAPER
Life history and captive rearing of the Wekiu bug (Nysius wekiuicola, Lygaeidae), an alpine carnivore endemic to the Mauna Kea volcano of Hawaii
Jesse A. Eiben Daniel Rubinoff
Received: 19 January 2010 / Accepted: 26 May 2010 / Published online: 16 June 2010 Springer Science+Business Media B.V. 2010
Abstract The hemipteran family Lygaeidae contains species that are overwhelmingly plant and seed feeders. The Wekiu bug, Nysius wekiuicola, a candidate endangered species endemic to the summit of the 4,205 m volcano, Mauna Kea, and the closely related AA bug, Nysius aa, are the only obligate carnivore scavengers of the family. Despite its unique diet, remarkable ecology, and high prole due to conservation concerns, there is still little known about the Wekiu bug. We present the rst detailed observations and descriptions of the Wekiu bug, including a complete life history. The Wekiu bug lays eggs singly or in small loose clutches, matures after ve nymphal instars, and can survive and reproduce at constant temperatures never found in its natural habitat. Our results clearly demonstrate the importance of behaviour, rather than pure physiological adaption, in an insects persistence in a harsh environment. The Wekiu bugs shift to carnivory from a suite of herbivorous congeners is a remarkable adaptive shift in an aeolian system bereft of vascular plants. Finally, we relate the specialized life history of the Wekiu bug to its conservation on the arid, frigid summit of the Mauna Kea volcano. This unique habitat is increasingly impacted by tourism and telescope facilities.
Keywords Scavenger Thermoregulation Aeolian
Telescope Seed bug
Introduction
The Wekiu bug, Nysius wekiuicola Ashlock and Gagn 1983 (Hemiptera: Lygaeidae), is a tiny (4.55.5 mm) ightless predator/scavenger endemic to the summit area (3,5004,205 m) of the Mauna Kea volcano on the island of Hawaii. On sunny days it basks and hunts for dead and dying insects along the edges of snowelds and in rock crevices where its prey has been immobilized by the cold. The Wekiu bug has been the subject of conservation attention and debate due to its very restricted range and peculiar life history as an alpine desert predator marooned on a volcano in a tropical archipelago. As such, the Wekiu bug has been a curiosity...