4.

CONSERVATION STATUS OF NATIVE TERRESTRIALINVERTEBRATES IN HAWAIfI

Wayne C. Gagne and Carl C. Christensen

ABSTRACT

The native invertebrate fauna of the HawaiianIslands consists of some 6,000 arthropod species, 1,000or more native land mollusks, and an undetermined num-ber of taxa belonging to other phyla. Many elements ofthis fauna are restricted to narrow geographical orecological limits. Because the evolution of the faunatook place in a high degree of geographical isolation,its members are unusually vulnerable to novel selectionpressures resulting from the introduction and spread ofnon-native animal and plant species and from ecologicaldisturbance caused by human activities. A great manynative invertebrates have become extinct since initialhuman settlement of these islands, and many other spe-cies are now in imminent danger of extinction. Never-theless, many native invertebrates survive in locationswhere the native vegetation is relatively pristine orwhere other favorable conditions are present. Effortsto conserve native invertebrates are hindered by inade-quacies of available taxonomic and ecological data andby the low priority usually accorded to invertebratesby those agencies charged with protection of the nativebiota. Efforts to protect native invertebrates are of3 types: taxon-specific protection under Federal andState Endangered Species Acts; site-specific actionsproviding protection to habitat necessary to the survi-val of native invertebrates; and preventive or eradi-cative actions targeting undesirable alien species.Although all extant species of Achatinella (a genus oftree snails endemic to Ofahu) have been listed as"endangered" by the U.S. Department of the Interior(USDI), no other Hawaiian invertebrates have yetreceived such legal protection. A preliminaryconservation assessment has been made for about 800species of insects, providing a cross-section ofecological functional groups, i.e., aquatic andsemiaguatic (Odonata: 28 species of Megalagrion),anthophagous and cleptoparasitic (Hymenoptera: 63

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ecologically linked.3. A sufficiently large extant population that the

probability of extinction is minimized (Simberloff1983).Where data are available, these commonalities permitthe conservation needs of invertebrate taxa to betreated in much the same way as those of other taxa.

ENDEMICITY AND VULNERABILITY

Among terrestrial macroinvertebrates, arthropodsand mollusks are the most frequent colonizers of tropi-cal oceanic islands. Other groups are only sporadi-cally successful in long-distance over-water disper-sal. Even so, successful natural colonizations of theHawaiian Islands by macroinvertebrates were infreq-uent. The 6,000+ species of Hawaiian terrestrial arth-ropods are derived from about 300-400 successful colo-nization events; similarly, the approximately 1,000species of native land mollusks are derived from about22-24 colonizations (Zimmerman 1948). The ability ofterrestrial invertebrate colonizers to speciate exten-sively on tropical oceanic islands is well known. InHawaifi it is exemplified in the explosive radiationsof drosophilid pomace flies (the 800+ endemic Hawaiianspecies, of a worldwide fauna of 2,500 species, aredescended from 1-2 colonizing immigrant species) andamastrid and endodontid land snails (the almost 300species of the endemic family Amastridae and approxi-mately 200 Hawaiian Endodontidae are apparently eachderived from single colonization events). At least ahalf-dozen insect genera each include more than 100 en-demic species. In some instances, members of these ra-diations have diversified over a relatively short timeto fill a broad range of ecological niches, which incontinental ecosystems are usually occupied by totallyunrelated taxa having a long evolutionary history ofadaptation to those niches.

The interplay of isolating mechanisms (geographi-cal, behavioral, ecological, etc.) has resulted in thehigh degree of localized endemicity and/or narrow nichespecialization characteristic of terrestrial inverte-brates in Hawai'i. Although no overall assessment hasbeen made, we estimate that the vast majority of ourterrestrial insect species are single-island endemics,and that the same holds true for nearly all of the lar-ger land mollusks and many of the minute species. Forexample, 87% of the 100+ species of picture-wingedDrosophila are restricted to single islands, and 9 ofthe 13 species inhabiting 2 or more islands are sharedby Maui and Moloka'i, islands which were joined withLana'i and Kaho'olawe to form a single island (termed"Maui Nui" by geologists) in periods of low sea levelduring the Pleistocene. Characteristically, these

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flies are found in higher altitude rain forests from

300 to 2,000 i, where they breed on various nativeplant materials. Like many of the host plants thatsupport them, the fly populations are patchy in distri-bution. Their population sizes are comparativelysmall, and most of the species are narrowly host-specific. Similarly, no species of the large acha-tinelline tree snails (genera Achatinella, Partulina,Perdicella, and Newcombia) is known to occur on morethan one island, and populations are often highly lo-calized within islands.

The native Hawaiian invertebrate fauna is unusualin that many ecological niches are occupied by taxawhich have only recently evolved the major adaptationsnecessary to exploit their particular niches. It in-cludes a large number of endemic species, most of themnarrowly precinctive in either ecological or geographi-cal terms, or both. Much more than in continental eco-systems, the diversity of Hawaiian invertebrates arosein place from the adaptive radiation of a few progeni-tor species. The coevolution of native invertebratesand other endemic plant and animal taxa took place inassociation with a different suite of predators andcompetitors than those present in continental areas.

The unusual nature of the Hawaiian invertebratefauna contributes to the vulnerability of its memberswhen their habitats are suddenly altered by human ac-tivity; or when habitats are altered by introduction ofnew predators or competitors, or even other species onwhich predators or competitors are dependent (Wells,Pyle, and Collins 1983) . Invertebrate taxa withrestricted geographical ranges are highly susceptibleto extinction as a result of habitat destruction causedby human activities. Polynesian and modern commercehas vastly increased the pace of immigration by plantand animal species and of the ecological changes re-sulting from the establishment of these novel competi-tors and/or predators. Native species able to adapt tonaturally occurring change taking place on a geologicalor evolutionary time scale are overwhelmed by a multi-tude of new influences acting simultaneously or inclose sequence. The large monophyletic adaptive radia-tions characteristic of the Hawaiian land snail faunamay be particularly subject to mass extinction, aslarge numbers of taxa over a wide area may be similarlyvulnerable to novel threats. Examples are the hypothe-sized catastrophic impact of predation by ants on eggsand juveniles of endodontid land snails (Solem 1976)and predation on achatinellid and other snails by theintroduced predatory snail Euglandina rosea (Wells,Pyle, and Collins 1983).

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PERTURBATIONS AND EXTINCTIONS

It is clear that the Hawaiian invertebrate faunahas suffered widespread recent extinctions, but docu-menting the extent and chronology of those extinctionsis a difficult task. To a considerable extent, this isbecause of our incomplete knowledge of the true diver-sity of the pristine biota. Ornithologists have onlyrecently learned of an unsuspected diversity of the na-tive avifauna of the Hawaiian Islands through study offossils and subfossils from limestone sinkholes andlava tubes (Olson and James 1982a, 1982b). Entomolo-gists who wish to estimate the original diversity ofthe Hawaiian arthropod fauna and the extent of recentextinctions are frustrated by an absence of fossildata, although hopes remain that such evidence willeventually be recovered. Malacologists have long beenaware of the occurrence of fossil land snails in areasnow devoid of these animals (Henshaw 1904; Perkins1913; Zimmerman 1948) and might be expected to have arather clear understanding of the extent of molluscanextinctions. Unfortunately, this is not the case, asuntil very recently studies of fossil land molluskswere strictly taxonomic in focus, while detailed infor-mation on the recent status of the living fauna was re-stricted to the large and colorful Achatinella treesnails of Ofahu; even here, post-World War II data arelimited. For minute species or for larger species in-habiting islands other than Ofahu, available data aregenerally few and out of date. Kondo (1970) has esti-mated that about 50% of the native land snail taxaoriginally inhabiting the Hawaiian Islands is extinct.In the absence of more precise data, his analysisstands as a first approximation.

It should be remembered, however, that biologists,paleontologists, and archaeologists have only recentlybegun to study prehistoric and protohistoric extinctionphenomena in Hawai'i. Furthermore, it is difficult todistinguish extinction events that may have occurred inthe hundreds of years before European rediscovery ofthese islands, from those that took place in the 50-75years following Captain Cook's landing and precedingthe mid-19th century observations of knowledgeablelocal naturalists.

Despite the lack of hard data regarding inverte-brate extinctions, we shall attempt to summarize theirrecent history. It is a history dominated by the ef-fects of anthropogenic habitat destruction and the in-troduction and spread of alien plants and animals. Al-though human impact is evident throughout, no singleagent is influential in all cases; rather, multipleagents acting sequentially or simultaneously have com-bined to cause catastrophic extinctions.

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Dextral pupillid snails of the genus Lyropupa wereabundant in such sites, as were certain amastrids,succineids, and other taxa adapted to arid conditions.Upland dry forests, as in Kohala and Kona on the islandof Hawai'i (Christensen 1983; Christensen 1984b) alsosupported diverse assemblages of land snails. Moistupland habitats contained diverse land snail faunas,and various native achatinellids (e.g., Achatinella,Partulina, Auriculella, Tornatellides), succineids(Succinea, Catinella) and helicarionids (Philonesia)may still be locally abundant in suitable locations.The original diversity of this zone is unknown, how-ever, since such ground-dwelling taxa as the Amastridaeand Endodontidae are probably under-represented in themodern fauna as a result of recent extinctions. Accu-rate knowledge of the diversity of this zone must awaitstudies of fossils from sediments in lava tubes.

Prehistoric Human ImpactsThe colonizing Polynesians converted much of the

lowlands to agricultural uses or to anthropogenicgrasslands (Kirch 1982). Destruction of the nativelowland vegetation could only have had a catastrophiceffect on the invertebrate fauna dependent on thatvegetation. Direct evidence of extinction of inverte-brates during this period is becoming available as aresult of interdisciplinary studies of fossil landsnails from archaeological sites. Kirch (1975) usedsuch data to demonstrate deforestation in HalawaValley, Moloka!i. In studies of sediments from lime-stone sinkholes at Barbers Point, Ofahu, Christensenand Kirch (in prep.) and their associates at BishopMuseum are finding a consistent pattern of extirpationof native amastrid and endodontid snails, probably oc-curring during the prehistoric period. Land clearanceby the Polynesians no doubt also had a devastatingeffect upon native arthropods.

The immigrant Polynesians brought a number ofplant and animal species with them. Many of the 2dozen or so plant species they introduced were highlydomesticated or infertile cultivars with little tenden-cy to invade undisturbed environments, although suchspecies as kukui (Aleurites moluccana), ti (Cordylineterminalis), and a few others became naturalized mem-bers of otherwise native communities (see Wagner,Herbst, and Yee, this volume). The impact of predationby introduced gekkonid and scincid lizards is impos-sible to assess. Of the 4 bird and mammal speciesintroduced prehistorically (the domestic chicken, dog,and pig/ and the Polynesian rat Rattus exulansi, thelast is likely to have had the greatest impact on na-tive invertebrates due to predation on ground-dwellinginsects and snails. Although feral pigs (Sus scrofa)now cause massive destruction to vegetation in native

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Johnson 1984) should remove any doubts regarding itsinfluence in Hawaifi. Qxvchilus alliarius, an aliensnail that became established in Hawai'i in the 1930*8,may also prey on native land mollusks (Severns 1984).Although Hyman (1939) regarded the terrestrial flatwormGeoplana septemlineata as a Hawaiian endemic, we sug-gest that it is not native here and may have had a se-vere impact on ground-dwelling snails. Parasitism bythe nematode Angiostrongylus cantonensis may also beharmful to native land mollusks. If so, this would bean indirect effect of the introduction of Achatinafulica, as this species is one of the principal inter-mediate hosts of this parasite and may have been thevehicle for its establishment in Hawai!i (Alicata1966).

The effects of rat predation on invertebrates havebeen studied in Australia and New Zealand (Best 1969;Gales 1982), where a number of rodent-free offshoreislands harbor large, flightless insects that are near-ly extirpated on the New Zealand mainland and otheroffshore islands, where they are recorded only as sub-fossils or as relicts in restricted favorable locationsin these areas (Key 1978; Ramsay 1978; Foggo and Meurk1981). In Hawai'i, apparently ratless Nihoa Islandprovides a close parallel, as large flightless cricketsand earwigs exist there but are unknown in the mainislands (Conant et al. 1984). Nihoa also has numerousspecies which represent native groups now extirpatedfrom lowlands on the main islands. In Hawaii, Nation-al Park Service workers have recently embarked on stud-ies of rodent impacts on native insects and other ani-mals, which should provide additional information inthis regard (Loope and Stone 1984; Stone et al. 1984).Predation or parasitism by other introduced animals ad-versely affects many other native invertebrates aswell, and indirect effects due to destruction of hostplants necessary to the survival of particular inverte-brate species may also be important; for example, 9species of pyralid moths (genus Hedylepta) have becomeextinct since 1900 as a result of biocontrol introduc-tions or because of loss of host plants (Gagne andHowarth, in press). Additional examples could be pro-vided (Howarth 1983a), but those listed are sufficientto outline the dimensions of the problem.

CURRENT DISTRIBUTION AND DIVERSITYOF NATIVE INVERTEBRATES

The classic work of Swezey (1954) provided muchdata about the occurrence of Hawaiian insects. Morerecently, Gagne (1979, 1980, 1981) has provided anassessment of the pattern of diversity among nativearthropods in Hawaiian ecosystems based on an extrapo-lation of his sampling of Acacia koa and Metrosideros

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are likely to be found in drier areas where native un-derstory vegetation has been replaced by introducedgrasses. Alien slugs and snails have invaded most hab-itats, even in some locations where native plant spe-cies predominate, and the predatory snails Euglandinarosea and Qxvchilus alliarius are widespread in suchlocalities (the former species occurring to elevationsof 1,000 m or more in places, the latter occurringabundantly to elevations in excess of 2,000 m). Al-though field data are very few, land snail diversity athigh elevations (> 2,200 m) is low and was probablynever high.

CONSERVATION STATUS AND STRATEGIES

Actions by governmental and other agencies to pro-tect native invertebrates are of 3 main types: taxon-specific protection under the Federal Endangered Spe-cies Act or state equivalents; site-specific actionsthat protect the habitats of native invertebrates (aswell as other native wildlife); and preventive or cor-rective actions targeting undesirable alien species.

Taxon-Specific ActionsOfficial recognition of threatened or endangered

status for native invertebrates has been slow in com-ing, compared to that for vertebrates. Local special-ists recognize large numbers of invertebrate specieswhich merit official recognition. As with the nativeavifauna and flora, a large percentage of native ar-thropods appear to have become extinct recently, andmany of the survivors should be considered candidatesfor endangered or threatened species categorization.The situation confronting large-sized terrestrial mol-lusks is even more grim, for if present trends continuemany will probably be extirpated over much of their al-ready greatly reduced range, largely as a result ofpredation by the introduced snail Euglandina rosea(U.S. Fish and Wildlife Service 1980; Hadfield andMountain 1981). Most native invertebrates will notsoon gain legal recognition without changes in politi-cal and public attitudes about the importance of inver-tebrates in human welfare and natural ecosystem func-tioning, and without funding for efforts to determinethe conservation status of taxa. A trend that shouldaccelerate this process has been to designate as endan-gered species whole genera or portions of them withsimilar ecologies or behavior. A recent example isFederal recognition of the endangered status of all ex-tant species (approximately 19 in number) of O'ahu treesnails of the genus Achatinella.

Gagne (1982) has made a preliminary conservationassessment of about 800 native terrestrial arthropodspecies. These species provided a cross-section of

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mm: union groups asioiiofs: 21seii-aguatie, and tawtestifial naww-winged damsel fliesof the genus Megalagrion (Odonata, Coenagrionidae); 60anthophagous and cleptoparasitic bee species of thegenus Nesoprosopis (Hymenoptera, Hylaeidae); 22 speciesof moths in the genus Hedylepta (Lepidoptera, Pyrali-dae); 140 species of detritivorous and nectarivorousnitidulid souring beetles of various genera (Coleop-tera); and 550 species of detritivorous and predaceouspomace flies in the genera Drosophila, Titanochaeta,and Scaptomvza (Diptera, Drosophilidae). From the out-set of the project, the problem was how best to deter-mine "endangered," "threatened," and "common" rankingin a manner that would give a uniform basis for asses-sing the conservation status of each species. A nu-merical scoring system called the "Index of Rarity" wasdeveloped, with values for taxonomic understanding,biological uniqueness, and impacts. According to thisranking, a priority for Federal review could be as-signed following the U.S. Fish and Wildlife Servicecriteria for consideration of listing species as endan-gered or threatened (these criteria are reviewed byWagner, Herbst, and Yee, this volume). The ideal situ-ation would be a detailed biological and systematicstudy of each species following bibliographic and col-lection analysis. Even though the "Index of Rarity"method is fraught with pitfalls, some elements of thissystem have been adopted by the Office of EndangeredSpecies for application nationally (G. Drewry, pers.comm.). The arthropod species were arrayed againstisland, general habitat type, the protection (or lack)afforded by existing reserves, etc., to attempt a sys-tems approach to their conservation and protection.

Based on data from this and other sources, theU.S. Fish and Wildlife Service has identified 335 spe-cies of native Hawaiian invertebrates as candidates forpossible inclusion on the List of Endangered andThreatened Wildlife (U.S. Fish and Wildlife Service1984). The bulk of these are "Category 2" taxa, forwhich available information indicates listing as endan-gered or threatened is possibly appropriate, but forwhich biological data on vulnerability and threats areas yet insufficient to justify listing. No Hawaiianinvertebrates were identified as "Category 1" taxa,those for which currently available data support theappropriateness of proposals for listing. No Hawaiianinsects have yet been listed, although insects comprisethe great majority of the recently identified animalcandidate species. Two Kaua'i cave invertebrates, theno-eyed big-eyed spider Adelocosa anops and the Kaua'icave sandhopper Spelaeorchestia koloana, were once un-der consideration for recognition, but with the seem-ingly interminable changes of criteria for completingthe review procedures necessary for listing, their

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processing has lapsed and needs to be re-initiated.Future lists of candidate taxa should include addi-tional native arthropods, as well as a much-expandedselection of terrestrial mollusks. (The amastrid genusCarelia, the only Hawaiian mollusks on the recent listof candidates, was assigned to "Category 3A," taxabelieved to be extinct.)

Hawaif i has a State Endangered Species Act to de-termine the conservation status of endemic inverte-brates, but so far responsible State agencies havetaken little initiative other than to follow Federaldeterminations. This inaction on the local scene re-flects a general lack of awareness or concern by gov-ernmental officials and the general public, about theunique nature of the Hawaiian biota (particularly itsterrestrial ecosystems) and its vulnerability to dis-turbance. A concerted effort to instill a conservationethic needs to be directed at all educational levels.

At the international level, the InternationalUnion for the Conservation of Nature and NaturalResources (IUCN) publishes the Red Data Books thatindicate the global conservation status of plant andanimal species as endangered, threatened, vulnerable,commercially threatened, etc. The Invertebrate RedData Book (Wells, Pyle, and Collins 1983) lists the ca.100 species of Hawaiian picture-winged Drosophila asvulnerable, and the 19 or so extant Achatinella treesnails and the no-eyed big-eyed spider as endangered.The IUCN is considering the once widespread narrow-winged damselfly, Megalagrion pacificum (Moore andGagne 1982), for endangered status.

Site-Specific ActionsFederal lands under the jurisdiction of the Na-

tional Park Service (Hawai'i Volcanoes National Park,Haleakala National Park) and U.S. Fish and WildlifeService (Northwestern Hawaiian Islands National Wild-life Refuge, particularly Nihoa and Necker Islands)contain important habitat for native invertebrates andreceive considerable protection from activities un-favorable to their continued survival. The full pro-tective provisions of the Federal Endangered SpeciesAct are applicable to other federally owned land inHawai'i. At the State level, the Natural Area ReserveSystem provides protection to some habitats vital tonative invertebrates, but additional reserves need tobe designated, and management efforts within existingreserves need to be increased. With regard to Stateregulation of designated Conservation District lands,preservation of native wildlife habitat is often accor-ded a low priority when conflicts arise with such com-peting land uses as hunting, commercial forestry, andenergy development. One non-governmental agency, The

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Nature Conservancy of Hawai'i, has become active in thepreservation of natural areas and has initiated a StateNatural Heritage Program to more accurately pinpointareas needing protection (Holt and Fox, this volume).In addition to those invertebrates recognized asthreatened or endangered by international, Federal, andState levels, species which are recognized by localauthorities as being de facto endangered or threatened(whether this arises from systematic analysis of pub-lished data or merely from a "best-guess" assessment)are considered in the setting of priorities for preser-vation of natural areas.

Restrictions on Importation of Alien OrganismsMany of the problems confronting native inverte-

brates stem from the introduction of alien plant andanimal species that may compete with, prey on, parasit-ize, or otherwise adversely affect native invertebratesor their host plants (see Howarth this volume). Afirst step in reducing such impacts should be astrengthening of quarantine and inspection regulationsfor materials shipped to Hawai'i from outside theState. Candidate biocontrol agents should be subjectedto careful environmental review prior to release. Thedemise of native moth species of the genus Hedyleptaand of various tree snails points out the hazards some-times associated with such well-intended introductions.

Selection and Design of Natural PreservesNatural preserve selection and design are topics

of considerable current research and debate (see bib-liographies by Harty, Harnish, and Lehman 1981; Killian1982; Pearsall 1983; and Franklin, this volume). Moststudies address preserve design requirements of verte-brates, especially birds, and to a lesser extent ofplants; a number debate the applicability or limita-tions of island biogeographic theory to conservationpractices. Few studies deal with habitat design forinvertebrates. Despite the limited consideration giveninvertebrates in these studies, natural habitat pre-serve design that contains sound scientific reasoningshould have applicability to all native biota. A suit-able approach may be to join elements of a systems ap-proach which combine the identification of criticalarea conservation (which delineates most threatenedinsular ecosystems) with endangered species determina-tion (see Jacobi and Scott, this volume). Both ef-forts, when combined and when based on sound scientificdata, could be productive conservation measures (seeEckhardt 1983). For now, conservationists concernedwith Hawaiian invertebrates will have to be contentwith preserve selection and conservation programs thatare tailored to birds and showy flowering plants, biot-ic elements that are better-known scientifically andthat more easily gain the attention of the public.

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Fortunately, almost any native habitat in some sem-blance of its original condition will contain manyinvertebrate species, and some Hawaiian invertebratessuch as the Achatinella tree snails have gained a cer-tain degree of public recognition in their own right.Invertebrate zoologists should, however, urge the pro-tection of certain unique ecosystems that do not harborendangered vertebrates but which are of sufficient im-portance to justify particular efforts on their behalfbased solely on the presence of rare invertebrates ordiversity of taxa. The recently discovered aeolianecosystems atop Hawai!if s highest mountains are worthyof protection, as are lava caves inhabited by endan-gered invertebrates. These latter sites are the sub-ject of study by the Cave Species Specialist Group ofthe lUCN's Species Survival Commission; investigationswill include terrestrial invertebrates in cave ecosys-tem conservation (Howarth 1983b). Small islands off-shore from the main Hawaiian Islands are likely to har-bor relict populations of native invertebrates, as wellas of endangered flowering plants.

Research NeedsAs the foregoing discussion has demonstrated, our

understanding of the conservation status and managementneeds of native Hawaiian invertebrates is deficient ina number of areas. Excluding general topics not specif-ically related to invertebrates, we believe the mostimportant research tasks to be undertaken are as fol-lows:

1. Completion of conservation assessment of se-lected terrestrial arthropods (particularly candidateendangered and threatened species), including analysesof both field and archival data.

2. Identification of additional candidate endan-gered and threatened species among native terrestrialmollusks. Achatinelline tree snails of the generaAchatinella, Partulina, Newcombia, and Perdicellashould be given priority consideration because distri-butional data are relatively good; the extreme vulner-ability of endodontid land snails recommends them alsofor consideration.

3. Biosystematic and ecological study of thosehigh ranking species determined by available criteriato be most vulnerable to extinction.

4. Development of methods to eliminate or amelio-rate influences (habitat destruction, spread of intro-duced organisms, etc.) that increase the vulnerabilityof native invertebrates to extinction.

5. Determination of the extent of suitable habi-tat necessary to support populations of particularvulnerable taxa and, if possible, the population sizenecessary to ensure their continued survival.

6. Design, delineation, and management of naturalreserves to provide protection to native invertebrates

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in conjunction with conservation needs of other biotic

elements.Though gathering this much information for a sig-

nificant portion of Hawai'i's diverse invertebratefauna is a tall order, a similar effort has alreadybeen completed for 6 species of endangered Mainlandbutterflies (Arnold 1983a, 1983b), and it is possibleto do the same for any of our species or species groupsgiven the necessary commitment of resources. What welearn about each species will speed—but not obviate—research on the remainder (Simberloff 1983).

CONCLUSIONS

We hope we have not painted too discouraging apicture of the conservation outlook for native inverte-brates in Hawaifi. Although much has already beenlost, recent discoveries of invertebrates living inpreviously unknown cave and high-altitude ecosystemsand of such unexpected creatures as the predatory geo-metrid caterpillar Eupithecia demonstrate that the na-tural environment of Hawai!i still includes a diverseassemblage of native invertebrates. We disagree em-phatically with those who say that it is already toolate to salvage a significant fraction of that assem-blage. One conclusion that is clear to any student ofHawaiian invertebrates is the need to educate the gen-eral public, and those in positions to influence land-use and conservation planning, about the uniqueness anddiversity of this important element of the Hawaiianbiota. We hope that future conservation efforts inHawai'i will accord invertebrates an appropriate placealongside the vertebrate and plant taxa that are theusual focus of such efforts.

ACKNOWLEDGEMENTS

We thank F.G. Howarth, S. Mountainspring, J.M.Scott, and C.P. Stone for their comments on thispaper. W.L. Wagner provided additional information.

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