36S 



Hawiiii — Our Living Resources 



For further information: 



Francis G. Hovvarth 



Bishop Museum 



DepartmenI of Natural Sciences 



POBox 1 9000- A 



Honolulu. HI %S17 



Kaua'i: implications for local and island-v\ide fruit tly 

 eradication programs. Pacific Science 47:1-16. 



Cole, F.R.. A.C. Medeiros. L.L. Loope, and W.W. Zuehlke. 

 1992. Effects of the Argentine ant on arthropod fauna of 

 Hawaiian high-elevation shruhland. Ecology 7.^:131.^- 

 1322. 



Conant. S.. C.C. Christensen. P. Conant. W.C. Gagne, and 

 M. Lee Goff. I9S4. The unique terrestrial biola of the 

 northwestern Hawaiian Islands. Pages 77-94 in 

 Proceedings of a Symposium on Resource Investigations 

 in the Northwestern Hawaiian Islands. University of 

 Hawaii, Sea Grant College Program, Honolulu. 



Cowie, R.H.. N.L. Evenhuis. and C.C. Christensen. Catalog 

 of the native land and freshwater molluscs of the 

 Hawaiian Islands. Bishop Museum Bull, in Zoology. In 

 press. 



Cuddihy. L.W., and C.P Stone. 1990. Alteration of the 

 native Hawaiian vegetation: effects of humans, their 

 activities and introductions. University of Hawaii Press, 

 Honolulu. 138 pp. 



Gagne, W.C. 1979. Canopy-associated arthropods in Acacia 

 koa and Metmsiileros tree communities along an altitudi- 

 nal transect on Hawaii Island. Pacific In.sects 2l:.'i6-82. 



Gagne, W.C, and F.G. Howarth, 1985. Conservation status 

 of endemic Hawaiian Lepidoptera. Pages 74-84 in 

 Proceedings of the 3rd Congress of European 

 Lepidoptcrology Cambridge, 1982. Karlsruhe: Societas 

 Europaea Lepidopterologica. 



Gambino. R, A.C. Medeiros, and L.L. Loope. 1990. 

 Invasion and colonization of upper elevations on East 

 Maui (Hawaii) b> PuravespnUi peiisylvanica 



(Hymenoptera: Vespidae), Annals of the Entomological 



Society of America 83: 1088- HW,"!. 

 Howarth, E.G. 1991. The environmental impacts of classical 



biological control, .^nnual Review of Entomology 



36:485-.'i09. 

 Howarth, E.G.. and W.P. Mull. 1992. Hawaiian insects and 



their kin. University of Hawaii Press, Honolulu. 160 pp. 

 Howarth, E.G., and G.W. Ramsay. 1991. The conservation 



of island insects and their habitats. Pages 71-107 in N.M. 



Collins and J. A. Thomas, eds. The conservation of 



insects and their habitats. Academic Press, London. 

 Nishida, G.M., ed. 1992. Hawaiian terrestrial arthropod 



checklist. Bishop Museum Tech. Rep. 1. 262 pp. 

 Otte, D. 1989. Speciation in Hawaiian crickets. Pages 482- 



526 in D. Otte and J. A. Endler, eds. Speciation and its 



consequences. Sinauer Associates, Sunderland, MA. 

 Perkins, R.C.L. 1913. Introduction to fauna Hawaiiensis. 



Vol. I. D. Sharp, ed. Cambridge University Press, 



Cambridge, xv-ccxxvii. 

 Polhemus. D.A. 1993. Damsels in distress: a review of the 



conservation status of Hawaiian Megalagrion dam- 



selflies (Odonata: Coenagrionidae). Aquatic 



Conservation: Marine and Freshwater Ecosystems 3:343- 



349. 

 Solem, A. 1990. How many Hawaiian land snail species are 



left? and what we can do for them. Bishop Museum 



Occasional Papers 30:27-40. 

 Stone, C.P 1989. Native birds. Pages 96-102 in C.P Stone 



and D.B. Stone, eds. Conservation biology in Hawaii. 



University of Hawaii Press. Honolulu. 

 Zimmerman, E.C. 1948. Insects of Hawaii. Vol. I. 



University of Hawaii Press, Honolulu. 206 pp. 



Drosophila as 

 Monitors of 

 Change in 

 Hawaiian 

 Ecosystems 



by 



David Foote 



National Biological Senice 



Hampton L. Carson 

 University of Hawaii 



Most of the world's named species of plants 

 and animals are insects, which are the 

 dominant component of the biological diversity 

 of most terrestrial and aquatic ecosystems 

 (Hammond 1992). In Hawaii, there are proba- 

 bly more than 10,000 native insect species, 

 whose functions in Hawaiian ecosystems 

 include prey for forest birds, pollinators of 

 native plants, and decomposers associated with 

 the cycling of plant nutrients. 



The population trends and distributions for 

 most Hawaiian insects are unknown and cannot 

 possibly be determined for more than a small 

 minority of species. To successfully develop 

 management strategies to monitor and preserve 

 our biological heritage, focal taxa or "indicator 

 species" need to be identified and used to devel- 

 op the biological information necessary for 

 making management decisions (Quinn and Kan- 

 1993), The data discussed here demonstrate 

 how one well-studied group of Hawaiian 

 insects, the Hawaiian Drosophila (Pomace 

 flies), may serve as a focal insect taxon. The 

 species diversity, underlying genetic diversity. 

 and evolutionary history of this group have been 

 described in detail. Their sensitivity to direct 

 and indirect environmental change has also 

 been demonstrated. These attributes make them 

 an ideal model species to monitor and under- 

 stand changes in patterns of biological diversity 

 associated with human impacts on native 

 ecosystems in Hawaii, 



Background 



Hawaiian Drosophila and. in particular, the 

 large "picture-winged" species within the 

 genus, are unique among living organisms 

 because different levels of biological diversity 

 within a single large, closely related group of 

 species can be characterized by researchers. 

 Polymorphisms {see glossary) due to inverted 

 chromosomal segments have been used to 

 assess genetic variation within and between 

 species. The banding patterns of all five major 

 chromosome arms among 106 species of 

 Hawaiian picture-winged Drosophila have 

 yielded a 5 million-year-old phylogeny (see 

 glossary) that is rooted to species on the island 

 of Kauai (Carson 1992). This work on the evo- 

 lutionary history of Hawaiian Drosophila aug- 

 ments an extensive systematic treatment of the 

 genus (Hardy 1965: Kaneshiro 1976). 



More recent genetic surveys have comple- 

 mented research on chromosome variation. 

 These include the description of nuclear and 

 mitochondrial DNA sequences and extensive 

 fieldwork that describes genetic variation with- 

 in and among populations and species of 

 Hawaiian Drosophila for allozymes (see glos- 

 sary) and quantitative traits (Carson et al. 1981; 

 DeSalle and Hunt 1987). Attention has focused 

 on characters thought to play an important role 

 in speciation. the process underlying the diver- 

 sification of Drosophila in Hawaii. 



