Great Basin Naturalist

Volume 59 Number 2 Article 3

4-30-1999

Biogeography and physiological adaptations of the brine genus (Diptera: ) in saline waters of the Great Basin

David B. Herbst University of California, Mammoth Lakes and University of California, Santa Barbara

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Recommended Citation Herbst, David B. (1999) "Biogeography and physiological adaptations of the brine fly genus Ephydra (Diptera: Ephydridae) in saline waters of the Great Basin," Great Basin Naturalist: Vol. 59 : No. 2 , Article 3. Available at: https://scholarsarchive.byu.edu/gbn/vol59/iss2/3

This Article is brought to you for free and open access by the Western North American Naturalist Publications at BYU ScholarsArchive. It has been accepted for inclusion in Great Basin Naturalist by an authorized editor of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. Great Basin Naturalist 59(2), ©1999, pp. 127-135

BIOGEOGRAPHY AND PHYSIOLOGICAL ADAPTATIONS OF THE BRINE FLY GENUS EPHYDRA (DIPTERA: EPHYDRIDAE) IN SALINE WATERS OF THE GREAT BASIN

David B. Herbst1

ABSTRACf.-Four species of the genus Ephydra are commonly found in saline waters within the hydrologic Great Basin: E. hians, E. gracilis, E. packardi, and E. auripes. Though none of these brine is endemic (distributions also occur outside the Great Basin), they all inhabit distinctive habitat types and form the characteristic benthic fauna ofinland saline-water habitats. The affinities ofeach species for different salinity levels and chemical compositions, and ephemeral to perennial habitats, appear to form the basis for biogeographic distribution patterns. Within any habitat, changing salinity conditions over time may impose physiological or ecological constraints and further alter patterns of population productivity and the relative abundance of CO-inhabiting species. Based on the physiology of salt tolerance known for these species, high salinity conditions favor E. hians in alkaline water and E. gracilis in chloride water. At lower salinities, based on limited habitat data, E. auripes and E. packardi are often more common, again showing respective preferences for alkaline and chloride chemical conditions. Specialized adaptations for alkaline carbonate waters are found in the larval Malpighian tubule lime gland of the alkali fly E. hians, while high salt tolerance in E. gracilis appears to be conferred by high hemolymph osmolality. Adaptation to ephemeral and low salinity conditions may be accomplished by swift adult colonizing ability and rapid larval development rates. It is hypothesized that adaptive specializations in both physiology and life history and varied geochemistry of saline water habitats across the Great Basin produce the biogeographic pattern of distributions for species in this genus. This perspective on the genus Ephydra, and possibly other biota of mineral-rich Great Basin waters, suggests that intercon­ nections among pluvial lakes may be less relevant to aquatic biogeography than chemical profiles developing in remnant lakes and ponds with the progression ofarid post-pluvial climatic conditions.

Key words: Ephydra, saline lakes, G1'eat Basin, osnwregulation, biogeography, salt tolerance.

Ever since the studies of Hubbs and Miller within the Great Basin have been only incom­ (1948), biogeographic studies of the aquatic pletely described. Habitat affinities are poorly fauna of the Great Basin bave been dominated known, and collection records typically have by a search for vicariance patterns. Distribu­ no associated physical or chemical data. tions of fish species often revealed patterns In addition to geographic barriers, differen­ suggesting pluvial interconnections among tiation ofpopulations may also result from dif­ lake basins and proVided evidence for post­ ferences in tbe physical and chemical features pluvial hydrographic changes including isola­ of aquatic habitats without producing geo­ tion leading to extinctions and species differ­ graphic isolation and endemism. Selection for entiation (Miller 1946, Smith 1978). In addition physiological adaptation may restrict species to fish, other obligate aquatic species (e.g., distributions to certain habitat types. Great spring snails, leeches, molluscs) have received Basin aquatic habitats often include waters an inordinate amount of attention because of with varied chemistry derived from high min­ the potential for endemic distributions arising eral content. The closed-basin drainages that out of the vicariance events of pluvial lake define the Great Basin collect and evaporate drying and recession, and tbe example set by water in saline lakes, ponds, and wetlands. Huhbs and Miller (Taylor 1960, Hershler 1989, Many springs (geothermal and otherwise) con­ Hovingh 1995). with poor dispersal tain high concentrations of dissolved solutes ability have also been studied in some depth and trace minerals. Streams in lower eleva­ in the Great Basin (e.g., Naucoridae; Polhemus tions ofthe basin and range also typically have and Polhemus 1994), but biogeograpbic pat­ relatively high conductivity and alkalinity. terns for most other aquatic invertebrates Physical conditions also may be quite varied

ISierra Nevada Aquatic Re~earch Lahoratory, University ofCalifornia, Route 1, Box 198, Mammoth Lakes. CA 93546, and Marine Science IJI,tlhlte. Unl­ ver:sity ofCalifornia, Santa Barbara, CA 931013-

127 128 GREAT BASIN NATURALIST [Volume 59

in terms of thermal regime (hot springs) and that some Ephydra had particular chemical ephemeral and episodic filling of playas and preferences. The objective of this paper is to intermittent streams. Gradients of chemical present evidence for the hypothesis that affini­ and physical variation form a habitat template ties of each species for different salinity levels that sets the stage for adaptive syndromes and chemical compositions, and ephemeral to determining the distribution and abundance perennial habitats, form the basis for biogeo­ ofspecies (sensu Southwood 1977). graphic distribution patterns. Geochemical evolution of major solutes in closed-basin saline lakes (e.g., Eugster and METHODS Jones 1979) may be a useful model for follow­ ing progression and patterns in the biological Contrasts of physiological specializations evolution and distribution ofsaline water biota for habitat chemistry are presented here as throughout the Great Basin. Water chemistry is evidence of adaptations that determine bio­ determined primarily by the following factors: geographic patterns. Data for comparisons of • drainage basin lithology of inflowing osmoregulatory physiology and salt tolerance waters (especially igneous vs. sedimen­ in Ephydra were derived from published tary); research (Nemenz 1960, Herbst et aJ. 1988). • mineral precipitation pathways depend­ Calculations of relative costs of osmoregula­ ing on the initial ratio of bicarbonate to tion were determined by applying the known calcium and magnesium and resulting osmotic gradients to calculations of the rela­ in lake brines with differing contents of tive energy required for the work of active the major cations Na+/Ca+2/Mg+2 and transport. Data on the range of known devel­ opment times in Ephydra were also summa­ major anions Cl-/S04-2/C03-2 (high bi­ em-bonate generally evolves into alka­ rized from published sources (Ping 1921 for E. line brines and low bicarbonate into packardi, reported as E. subopaca; Collins chloride-sulfate brines, and low salinity 1980a for E. gracilis, reported as E. cinerea; and Herbst 1986 for E. hians). Distribution conditions may retain similar content of data were derived from Wirth (1971) and fur­ bicarbonate and Ca/Mg without forming ther supplemented by collection records and precipitates); habitat chemistry data of the author. • fractionation processes which enrich highly soluble (conservative) ions such as RESULTS Na and Cl and deplete others through carbonate mineral formation, release of Ecological and physiological limitations carbon dioxide gas, and biogenic reduc­ under changing salinity conditions in salt lakes tion ofsulfate for example. appear to result in varied distribution and pro­ Progressive enrichment from carbonate to ductivity of Ephydra spp. Distribution maps sulfatochloride to chloride waters appears to (Figs. 1, 2) and limited habitat data suggest occur with the concentration of inflowing high salinity conditions (usually >25 g-L-1) waters over time and distance along intercon­ favor E. hians in alkaline water and E. gracilis nected evaporation basins of varied volume in chloride water. In low salinity «25 g'L-l) (Hutchinson 1957). Spatial and temporal com­ and ephemeral waters, E. auripes and E. ponents of variation in water chemistty form a packardi are often more common, again show­ habitat template that may be the foundation ing respective preferences for alkaline and for shaping the distribution of saline water chloride chemical conditions. The general organisms. prevalence ofE. gracilis in the eastern, and E. Four species of the genus Ephydra are hians in the western, Great Basin correspond commonly found in saline waters within the to the trend in lake geochemistry being derived hydrologic Great Basin: E. hians, E. gracilis, from eastern sedimentary vs. western igneous E. packard~ and E. auripes. Though none of lithology in the generation of chemical profiles these brine flies is endemic (distributions also (Jones 1966, Fiero 1986). Habitats in which occur outside the Great Basin), they inhabit 1 have collected E. auripes and E. packardi distinctive habitat types and form the charac­ are typically small, shallow seep and spring teristic benthic insect fauna of inland saline outflows onto saline playas, whereas E. hians water habitats. Wirth (1971) first suggested and E. gracilis habitats are often large, deep 1999J BIOGEOGRAPHY OF EPIlYDRA 129 perennial lakes or ponds. Within the Owens­ tial difference. As a first approximation, the Death Valley system of the southwest Great osmotic concentration gradient can be used to Basin, E. auripes is common in alkaline seeps estimate energetic costs assuming cuticular around Owens Lake, while at the Death Valley permeability (P) and surf"ce area (A) and elec­ terminus of these once-interconnected basins, trical gradient (E) arc similar for both species E. packardi dominates the chloride waters of and chemical conditions, and all other units small seeps. are constants; the relative cost becomes pro­ Comparisons of osmoregulation in E. gra­ portional to the natural log of the osmotic gra­ cilis and hians (Fig. 3) show that E. gracilis dient ChiC] (Fig. 4). Thc cost functions shown regulates hemolymph osmolality at an unusu­ indicate that E. gracilis may inhabit more saline ally high level for insccts (700-1000 mOsm; waters bccause higb hemolymph osmolality Ncmenz 1960), and ahout 3 times that found reduces the gradient, and relative cost is only in E. hians (Herbst et al. 1988). The energetic about half tbat for E. hians at an equivalent cost of osmoregulation against this gradient external salinity. Chloride waters tend to be may be calculated as shown by Potts and Parry more hyperosmotic than carbonate because (1964): the osmotic concenb"ation is higher for an equivalent TDS (g'L-1) concentration. While E. gracilis possesses physiological Calones. = '"L...~tll solutes PA . RT· In q,C + nFE 1 adaptation for life in high saliuity chloride water, E. hians shows much greater tolerance where P and A refer to integumentary perme­ for life in carbonate waters (alkaline soda ability and area, R is the gas constant, T is lakes) than in chloride waters. LC-50 toxicity temperature, Ch and CI are the high and low values occur at lower concentrations in chlo­ concentrations of the concentration gradient ride watcr than carbonate water (Figs. 5A, 5B). (external or internal), n is ion valence, F is E. hians is adapted to alkaline carbonate lakes Faraday constant, and E is the electrical poten- by virtue ofthe lime gland (Herbst and Bradley

,------.-

, ,, , , ,, ,I , . o , , , • : ,, , --I---ll­ ------,-- --1- .... --'· ------1------1 I , I , ,I , o , · , , , ·00 --- ~ •• , , , • ,I • , • , , ."0 ,, 0 , • ,I I ,[Oil II , ,.. , , 00 , , .. ,I , ,I , , , I " , , 0 , " , , , , , , , . , ., , o 2h ,,,-./~~ o ' , , " , , , , I------~ , ,, , ,, \------, • • ' , ( ... 1 • fiJ •: ", I '" " 1 ','-.;"" , '-.;" , o " , , , , •• • , ,, " I• Ephydra gracilis , , I• Eplly

Fig. 1. Distribution of Ephydm gracilis and Ephydra :Fig. 2. Distribution of Ephydra packardi and Ephydm hia.t~ within the hydrographic Great Basin. Based on auripes within the hydrographic Greal Basin. Based on Wirth (1971) and supplemental collections. Wirth (1971) and supplemental collections. 130 GREAT BASIN NATURALIST [Volume 59

1000 • • Iso-osmotic nne 900 • • E • 800 • ~ • 700 • •0 - • Ephydra gracilis ~ • 800 • • •0 • 0 500 • •~ 400 • 0 • •0 • 8 300 • • 200 • -- t • 0• • 100 • o+---t---+---+--+----..<--t--+---t---+-----i o 500 1000 1500 2000 2500 3000 3500 4000 4500 5000

Osmotlc concentration of lake water (mOsm)

Fig. 3. Osmotic regulation in Ephydra hians (from Herbst et ai. 1988) and Ephydra gracilis (from Nomenz 19(0). Iso­ osmotic line indicates where internal equals external coneentrations.

3

•0 ,~ ~ 25 Ephydra Mans "f 2 0 ~ 1.5 ,• Ephydra gracilis ,0 d 1 0 -~ U • ~ 0.' ~ o+--"---+---"'--+--t---+---+--t---t---+--r-_ o 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 Osmotic concentration of lake water (mOsm)

Fig. 4. Relative cost of osmoregulation in Ephydra !lians and Ephydra gracilis based on osmotic gradient (cost is mini­ mum where hemolymph and lake water are iso-osmotic).

1989). The lime gland is a modification of one resting stages or diapause, colonLdng ability, pair of the Malpighian tuhules in this species and rapid development (Williams 1987). A wherein calcium is concentrated and bicar­ comparative summary of ephydrid develop­ bonate/carbonate are removed from the blood ment rates in ephemeral vs. perennial habitats by forming a calcium carbonate precipitate is given in Table 1. E. packardi has a short within the tubules ("lime"). The intolerance development lime, comparable to Seatella shown by E, hians for chloride waters may pieea from ephemeral ponds, This contrasts indicate reduced capacity for regulating this with the longer and more flexible develop­ anion though this species can survive in lower ment times seen in E. gracilis and E, hians, salinities of chloride water as suggested by the which may extend larval growth over long convergence of toxicity data for longer expo­ periods when exposed to the stress of reduced sure times and lower salinities (Fig. 5), food availability or increased salinity. Species Completion of a life eyele in ephemeral of temporary waters, without resting stages, aquatic habitats involves such adaptations as do not have this option and must develop 1999] BIOGEOGRAPHY OF EmYVRA 131

TABU 1. Duration oflarval development in selected Ephydridae. Range oflarval development Ume for instal'S 1--3 (days) Habitat type Reference

Ephydra packard; 11-13 ephemeral saline pools Ping 1921 Ephydra gracilis 16-30 saline lakes Collins 1980a >100* , Ephydra hions" 15-$ saline lakes Herbst 1986 >120* ScateUa pice<: 4--11 ephemeral ponds Connell and Scheiring 1982

·iJodet" food limitation or ..alinity s~ ··Range ror populations from Mono aDd Abert W;e;s at 50 g'L-1 sW"nity ~d QCeSS !OOd

rapidly to reach maturity and disperse to new JOO ~ habitat. E. packa,·di exhibits this type of life history. In addition, E. packardi exhihits best growth at 40-{)O g-L-1 and cannot survive -- 200 r L above 90 g·L-l (Ping 1921), well below the ~ g limits for E. gracilis or E. hiam. 150 • ~ Cllloride walllr DISCUSSION " '00

50 Based on the physiology and expense ofsalt tolerance, high salinity conditions favor E. a hians in alkaline water and E. gracilis in chlo­ 72 " Exposure "TIme (hours) ride water. At lower salinities, based on lim­ ited habitat data, E. auripes and E. packardi are often more common, again showing respective preferences for alkaline and chlo­ 7000

ride chemical conditions. Specialized adapta­ '500 tions for alkaline carbonate waters are found in the larval Malpighian tubule lime gland of - 5000 the alkali fly E. hians, while high salt tolerance I 5500 in E. gracilis appears to be conferred by high hemolymph osmolality. Adaptation to ephe­ meral and low salinity conditions may be .500 achieved by rapid larval growth rates as seen -- in E. packard;. Biogeographic patterns ofasso­ .,. ciation with chemical and regional differences " Exposun TIm- (hours) in habitat types correspond with differing abil­ ities ofthese Ephydra species. Flg. 5. Salt tolerance in third instar larvae of Ephydra mans exposed to saline waters where either carbonate or While water chemistry may broadly define chloride llre the dominant anions (from Herbst et aI. the distribution ofEphydra spp. among differ­ 1988). LC·50 values are lethal concentrations at which ent habitat types, salinity changes within a half the exposed population dies as determined in mortal­ habitat appear to control population produc­ ity bioassays: A, expressed as total dissolved solids exter­ tion of species and the relative abundance of nal salinity (g'L-l); B. expressed as external osmotic con· centration (mOsm = milliosmolal). co-existing species. The intermediate salinity hypothesis (Herbst 1988) proposes thai abun­ dance of salt-tolerant organisms is limited by in Ouctuating sail lakes. Increased abundance physiological stress at high salinities and by of E. hiam at (California) and E. ecological faclors, such as predation and com­ gracilis al Great Salt Lake (Utah) occurred petition, in more diverse communities at low during periods of salinity dilution (Winget et salinities (Fig. 6). Field observations have pro­ al. 1972, Herbst 1988). During a period of vided evidence ofchanging population dynamics dilution of already low salinity at Abert Lake 132 GREAT BASIN NATURALIST [Volume 59

Intermediate Salinity Hypothesis [Saloo Lak.e Productivity, Herbst 1968J

--_.. _,. Limitations due to biotic Limitations due to interactions in a diverse physiological stress community at low salinity of increasing salinity (competition, predation) V ~

SALINITY »

Fig. 6. Intermediate salinity hypothesis (Herbst 1988).

(Oregon), E. hians abundance was reduced in These data also might be applied to under­ the presence of increasing numbers of other standing other zoogeographic patterns in the benthic invertebrates (Herbst 1988). Prelimi­ Great Basin. Brine flies playa central trophic nary results of mesocosm salinity gradient role in saline lakes as consumers of benthic experiments also support the intermediate algae, in turn providing one of the principal salinity hypothesis (Herbst in preparation). food sources used by migratory and breeding Dilution of the chloride-ricb waters of the shorebirds and waterfowl (Jehl 1994, Rubega Great Salt Lake has been followed by colo­ and Inouye 1994). The historical development nization and increased abundance of E. hians, ofavian migratory routes and breeding colonies where otherwise only E. gracilis was present along tbe Pacific Flyway within the Great Basin (Welker and Havertz 1973, Collins 1980b). during the Holocene may therefore be linked This last example suggests coexistence can to salinity-related changes in the population occur within transitional regions ofthe physio­ production of Ephydra in different saline lake logical tolerance zones ofEphydra species. basins. Assuming that optimum production for Saline water habitats appear to be parti­ E. hians is in the 25-100 g'V I range, and for tioned among the 4 species of Great Basin E. gracilis in the 100-200 g-L-1 range, proba­ Ephydra along gradients of chemical composi­ ble historical locations and changes of feeding tion, salinity, and stability (Fig. 7). This habitat grounds may be reconstructed from paleo­ template model (sensu Southwood 1977) pre­ salinity records alone. dicts expected species distributions and poten­ Physiological and life history traits related tial changes in range and coexistence in space to the selection regime of saline water babitats and time under varied environmental condi­ could provide distinctive characters for cladis­ tions. As a test of this conceptual model, fnr­ tics analysis and permit further investigation ther research on Ephydra spp. should include of the phylogenetic relationships in the genus relating zoogeographic distributions to ionic Ephydra and other (Mathis 1979a). tolerance and habitat chemistry using triangu­ Mathis separates Haloscatelfa from other sub­ lar anion diagrams, and comparisons of colo­ genera of Lamproscatelfa partly on the basis of nizing ability, life history traits, and population saline water habitat preferences, and it would abundance along environmental gradients. For be useful to examine further whether chemical E. auripes, for which little data are available, tolerances among the species of the subgenus the conceptual model predicts that this species correspond to the cladogram presented (Mathis has short development time, rapid coloniza­ 1979b). The 5 Nearctic species of Lamprosca­ tion of new habitats, lower salt tolerance than lelia (Haloscatella) spp. can be found within E. hians, greater survival in carbonate than the Great Basin, aod Mathis suggested that chloride chemistry, and poor competitive abil­ this is the zoogeographic origin of this group. ity in coexistence with E. hians. Isolation through physiological adaptation to 1999J BIOGEOGRAPHY OF EpHYDRA 133

perenniel (fakes) E. gracilis E. hians

SALINITY HABITAT STABILITY

ephemeral (po~, see!")

FRESHWATER HABITATS

< CHLORIDE CARBONATE >

Fig. 7. Saline water habitat template for the distribution of Great Basin Ephydra. Each corner of environmental tem~ plate inhabited primarily by a single species. varied water chemistry may in fact be a more alkaline water but can live in moderdte salini­ likely explanation for speciation and distribution ties ofsulfate water. These distributions suggest in this group than through repeated vicariance adaptations to different chemical conditions through glaciation events as proposed by allow habitat partitioning. Fossil preservation of Mathis. ostracodes permits their use as paleosalinity Other species in the genus Ephydra exhibit indicators. Other taxa with probable specific thermal adaptation. E. geodeni inhabits hot chemical-habitat affinities and potential for springs in freshwater to moderate salinities biogeographic interpretation through geochem­ (Barnby 1987). E. thermophila and E. bruesi istry include diatoms (Blinn 1994), corixids are endemics of acidic and alkaline thermal (Scudder 1976), and branchiopod crustacea springs, respectively, in Yellowstone National (Bowen et al. 1985). Resh and Sorg (1983) have Park (Collins 1977). Physiological adaptation shown that lithium tolerance in the shore bug and habitat partitioning along thermal, con­ Saldula usingerina permits survival in certain ductivity, and pH gradients may contribute to thermal springs and can be used to predict the origins and zoogeographic distribution of local habitat distribution. these species. The remnants of pluvial Great Basin lakes Other Ephydridae found in athalassic saline are primarily saline bodies of water. Only a water habitats of tbe world may also exhibit few perennial saline lakes remain (including biogeographic associations with geochemistry. Mono Lake, Abert Lake, Great Salt Lake, and Physiological adaptation to varied habitat geo­ Pyramid and Walker lakes), and many ephe­ chemistry may exist in homologous ephydrid meral ponds, wetlands, and spring seeps are fauna io isolated desert regions such as the also disappearing. Habitat loss has resulted spp. of the South American Alti­ primarily from sb'eam diversion and spring plano, Ephydrella spp. of the Australian inte­ development. Perennial lakes and ponds and rior, and Ephydra spp. of the Old World other habitat refugia are threatened and must (Wirth 1975). become part of a program of aquatic systems Use of biological proxies as indicators of protection in the Great Basin to ensure the water cbemistry of closed-basin lakes is well mosaic of habitats is available that has permit­ illustrated by the distribution of certain ostra­ ted the diversification of life such as is repre­ code taxa in saline waters (Forester 1986). sented in the Ephydridae. Species in the genus Limnocythere appear to In conclusion, the following general syn­ have varied anionic preferences) with L. staplini dromes of biogeographic patterns in the Great found in chloride and sulfate waters, L. sap­ Basin are presented to reflect the importance paensis in alkaline waters, and L. cetiotube-rosa ofboth vicartance and geochemical variation: in waters of mixed chemistry. Another species. • obligate aquatic species (or those with Candona rawsoni, is fowld only in low salinity poor dispersal ability) having restricted 134 GREAT BASIN NATURALIST [Volume 59

or endemic distributions (habitat isola­ Meadows) drainages, Death Valley system, Califor­ tion through vicariance); nia-Nevada. Proceedings ofthe Biological Society of Washington 102:176-248. • obligate aquatic species with widespread HOVINGH, p. 1995. Zoogeographical studies ofrivers in the distributions (wide tolerance); Great Basin, USA: amphibians, molluscs, and leeches. • vagile species with widespread distribu­ Bulletin of the North American Benthological Soci­ tions and wide habitat tolerance; ety 12:192. HUBBS, C.L., AND R.R. MILLER. 1948. Correlation between • vagile species with restricted distribu­ fish distribution and hydrographic history in the tions due to specialized adaptations for desert basins ofwestem United States. Pages 17-166 certain chemical or physical babitat in The Great Basin, with emphasis on glacial and conditions (e.g., Ephydra, others). postglacial times. Bulletin of the University of Utah 38, Biological Series 10. HUTCHINSON, G.E. 1957. 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Habitat, the templet for ecolog­ ology 34.. 903-909. ical strategies? Journal ofAnimal Ecology 46:337-365. HEHSHLER, R 1989. Springsnails (Gastropoda: Hydrobi­ TAYLOR, D.W 1960. Distribution of the freshwater clam idae) ofOwens and Amargosa River (exclusive ofAsh Pisidium ultramontanum: a zoogeographic inquiry. 1999] BIOGEOGRAPHY OF EpHYDRA 135

American Journal ofScience 258A:325-334. WlRTH, w.w. 1971. The brine flies of the genus Ephydra WElKER, M.e., AND D.S. HAVERTZ- 1973, A study ofspecies in North America (Diptera: Ephydridae). Annals of diversity ofthe genus Ephydra on the Great Salt Lake. the Entomological Society ofAmerica 64:357-371. Utah Academy Proceedings 5om'...80. _----,' 1975 A revision of brine ilies of the genus Ephy­ WIL.WAMS, D.D. 1987. The ecology of temporary waters. dro of tbe Old World (Dip'era, Ephydridae). Ento­ TImber Press, Portland. OR. 205 pp. mo)ogica Scandinavica 6:11-44. WINCET, R.N., D.M. REES, .... ND G.C. CoLLETf. 1972. Insect problems associated with water resource Received 18 March 1998 development of Creat Salt Lake Valley. Pages Accepted ISJune 1998 156-166 in The Great Salt Lake and Utah's water resources. Utah Water Research Lab, Logan.