Evolutionary ecology of aeolian and subterranean habitats in Hawaii

Author:

Howarth, Francis G.

Title:

Evolutionary ecology of aeolian and subterranean habitats in Hawaii

Periodical:

Trends in Ecology and Evolution

Year:

1987

Volume:

2

Pages:

220-223

Subject:

Wekiu bug Cave fauna Aeolian

Summary:

Hawaii's biota has been considered poorly developed with many functional roles within ecosystems unfilled. Inhospitable lava flows, high altitude stone deserts, and subterranean habitats in the Hawaiian Islands are known to support a variety arthropod species that are endemic to the Hawaiian Islands. However, recent discoveries in paleontology and ecology has shown that newly emerging functional roles fill in ecological time rather than in evolutionary time and that four recently-discovered Hawaiian ecosystems, in apparently desolate places, not only expand the view of island ecology but may also provide ideal systems that are critical with regard to testing continentally-derived theories on the evolution of community structure, the evolutionary ecology of high stress environments, and evolution in general. This document describes how specialized species such as a lava cricket such as the endemic Caconemobius fori, (Family Gryllidae), and a wolf spider, Lycosa sp., hide in the cracks of an ecosystem that is described as neogeoaeolian, (an environment that consists of wind-supported new unvegetated lava flow habitats). One such habitat where the specialized species are found is located at the 1000m elevation of Kilauea Crater that is on the southeastern portion of the island of Hawaii. This is where these insects emerge at night and forage on windborne debris. Also described is the wekiu bug, Nysius wekiuicola, a highly aberrant flightless, black, long-legged Nusiu that is closely related to a native complex of species. This species feeds on dead and moribund insects that are stunned by the cold when carried to the summit of Mauna Kea on the Hawaii Island. On the island of Maui, a flightless moth, Thyrocopa apatela is another aeolian species that lives on the summit of Haleakala. This species builds silken webs under larger rocks near the summit and feed on wind-borne debris that consists mainly of dried leaves of the endemic alpine shrub Dubautia menziesii. Thyrocopa apatela is closely related to flighted scavenging species in nearby forests on the lower slopes of Haleakala and another type of wolf spider, the Lycosa cf hawiiensis, often seizes the larval webs. In addition, approximately 45 species of cave-adapted animals are known to the archipelago that evolved independently on five of the main islands of Hawaii -- Kauai, Oahu, Molokai, Maui, and Hawaii Island. However, since there are fewer cave-like habitats on the older islands, many of the cave animals occupy lava tubes that are located on the island of Hawaii -- the youngest island of the archipelago.

Label:

Insects

Date:

1987

Collection:

Periodicals