Great Basin Naturalist Memoirs

Volume 3 The Endangered Species: A Symposium Article 8

12-1-1979 Rare aquatic , or how valuable are bugs? Richard W. Baumann Monte L. Bean Life Science Museum and Department of Zoology, Brigham Young University, Provo, Utah 84602

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Recommended Citation Baumann, Richard W. (1979) "Rare aquatic insects, or how valuable are bugs?," Great Basin Naturalist Memoirs: Vol. 3 , Article 8. Available at: https://scholarsarchive.byu.edu/gbnm/vol3/iss1/8

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 Memoirs by an authorized editor of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. RARE AQUATIC INSECTS, OR HOW VALUABLE ARE BUGS?

Richard W. Bauinann'

Abstract.— Insects are an important element in the analysis of aquatic ecosystems, (1) because the limited dis-

persal abilities of many aquatic species means that they must make a living under existing conditions, and (2) be- cause they are often sensitive to slight changes in water and stream quality, thus making excellent indicators of the physical and chemical conditions in a system. Examples of rare, ecologically sensitive species are presented from the Plecoptera, Ephemeroptera, and Trichoptera. Detailed studies of rare aquatic species should produce impor- tant information on critical habitats that will be useful in the protection of endangered and threatened species in other groups of and plants.

I use the term rare instead of endangered the distribution patterns of certain species fit or threatened, because no aquatic insects are nicely with a model of island biogeography. presently on the United States hst of endan- Many stoneflies (Plecoptera) are mostly re- gered fauna. The term is still relative, stricted to pristine habitats characterized by though, because my experience indicates that cold, clean continuously flowing streams at nearly every species can be plentiful if high elevations or in special spring-fed habi-

sought at the right place at the right time. tats. It thus follows that if the particular hab-

Aquatic insects are useful to anyone study- itat in which they occur is threatened, then ing aquatic habitats because they usually they almost automatically become rare and meet two criteria that are essential in assess- may become extinct. Such species popu- ing aquatic systems. First, they often have lations are often considered relicts of faunas very limited dispersal abilities, which means that were once more prevalent when more that they must stay and make a living under ideal conditions occurred. existing conditions. Second, they are often Studies on the stonefly genus Amphine- sensitive to slight changes in water quality, so mura (Baumann and Gaufin 1972, Bauman

their presence or absence tells something 1976) showed that it was a Palearctic genus about the physical and chemical conditions in that had extended into the Neotropical the system. Realm and was still present in western North Because the conditions present in a given America in limited relictual populations. Al- habitat determine which species can live though four species showed fairly wide distri- there, these organisms become living in- bution patterns in the United States and Mex- dicators of water quality in aquatic ecosys- ico, three species were restricted to a single tems. If these organisms are invertebrates mountain range. Amphinemura apache oc- which exist at low levels in the food web, this curred in the Chiricahua Mountains of Ari-

is an advantage. Invertebrates are easier to zona, A. reinerti, was limited to Sierra Potosi, study than are larger animals, because they Mexico, and A. piiehhi was found in a moun- are more abundant and usually do not carry tain drainage near Veracruz, Mexico. the emotional stigma associated with large These A7nphinemiira species are poor fliers vertebrates. They can also indicate adverse and almost need a water connection for dis- habitat problems sooner, so that adjustments persal. They live only in small streams that can be made in water or stream quality be- flow all year around and are of high quality. fore the top carnivores are severely affected. Their distribution patterns closely follow the During my studies of aquatic insects in spruce-fir and high pine forests in the south- western North America, I have found that western United States and Mexico. They are

'Monte L. Bean Life Science Museum and Department of Zoology, Brigham Young University, Prove, Utah 84602.

65 66 Great Basin Naturalist Memoirs No. 3 thus good indicators of a special aquatic habi- esting examples and their special habitat re- tat in western North America. quirements are: Goriella baiimanni, organic Another example of restricted distribution ooze in spring seeps; Psychronia costalis, in the stoneflies is Capnia lacustra Jewett, small meadow streams above 8,000 feet; Des- which only occurs in Lake Tahoe. It carries mona bethida, small spring streams. on its entire life cycle under water at depths The number of rare aquatic insects is quite of 100-400 feet (Jewett 1963, 1965). Only large because of the number of different one other similar stonefly is known, and that aquatic habitats available and the ability of is the genus Baikaloperia (Zapekina-Dulkeit insects to fit into relatively small niches with- and Zhiltzova 1973), in Lake Baikal, Siberia. in those habitats. This is actually a positive

It is also wingless and possesses similar mor- value, however, because it allows the re- phological and ecological traits. It is not sur- searcher to more closely understand the eco- prising that these two deep, ancient lakes system since it can be divided into smaller contain similar rare species which evolved parts. under specialized conditions and will be lost Two final examples of rare insects that if their habitat is destroyed. have very specific habitat requirements are Much attention has been given to several the met-winged midges and the water penny fish species that occur in the Colorado River . drainage such as the Humpback Chub, Ra- Net-winged midges are flies which have zorback Sucker, and Colorado River Squaw- become adapted to living in torrenticolus fish. These fish developed through time in habitats. The larvae are greatly modified into another type of specialized habitat that ex- chitonlike organisms that attach themselves cluded the salmonids and allowed other taxa to the substrate by sucking discs. They live to radiate into the open niches. Invertebrate only in clean, cold, well-aerated waters species have also developed imder similar which have a stable, smooth-grained sub- conditions and several forms also occur in the strate. Thus they can be excellent indicators Colorado River drainage. Edmunds (1976) of these habitat conditions that occur at falls

lists several mayfly species which are rare and quick-flowing mountain torrents. Hogue and restricted to the Colorado River drainage (1973) lists several Blephariceridae species and similar large warm rivers in western that are presently known only from a single North America. locality or mountain range. This is not simply The following are a few examples of rare an artifact of incomplete collecting, but a re- mayfly species and an indication of where sult of poor adult dispersal ability plus the they occur in the United States: Analetris very specialized habitat requirements of the eximia. Green River; Lachlonia saskotchewa- larvae noted earlier. nensis. Green, Colorado, and White Rivers; Water penny beetles have an adult stage Anepeorus rusticus. Green River; Home- tliat looks like a terrestrial but a larval oneuria sp. Escalante and Colorado Rivers. stage that is highly modifed for life on the These invertebrate species provide additional bottom of streams. The larva is greatly flat- evidence that our large, warm, western rivers tened so that the head and appendages are contain species that have adapted to completely hidden under the thoracic and special conditions critical for their survival. abdominal sclerites. The single eastern spe- Caddisflies or the Trichoptera are inter- cies herricki is rather widely dis- esting insects that occur in a wide variety of tributed, but the five known western species aquatic habitats. Most are good fliers and dis- have very restricted distributions (Brown and tribute freely, but many species are restricted Murvosh 1974). Two species, P. montanus to a certain habitat because of the larval re- (White Mountains, Arizona) and P. arizo- quirements. nensis (Chiricahua Mountains, Arizona) have Wiggins (1977) published an outstanding very limited areas of occurrence. An inter- distri- work that makes it possible for any trained esting note is that this type of limited biologist to classify caddisfly larvae to genus. bution pattern is also exhibited by several

Thus it provides another tool for evaluating species in the Plecoptera, Trichoptera, and habitats using aquatic insects. A few inter- Ephemeroptera. 1979 The Endangered Species: A Symposium 67

Many more examples of "rare" aquatic in- should place renewed emphasis on studies of sects could be given which probably fit into them. We must, however, be aware of the the endangered or threatened categories as fact that people in general do not imderstand presently understood. They are exciting to the scientific value of insects and might react me for pure scientific studies of zoogeo- poorly to "bugs" being used to justify the graphy and phylogeny. However, I feel that preservation and conservation of special eco- the real value is not simply to say "I found systems. However, scientific investigations of another rare creature," but instead to make high quality must utilize all possible avenues us more sensitive about the critical habitat of investigation if problems are to be solved conditions which produced these rare species. with a minimum expenditure of time, effort, Insects tend to be more abundant and are and resources. tlius easier to study without affecting popu- It is also important that we do not attempt lation dynamics. They are also usually more to overstate the value of "rare" species as economical and easier to sample because habitat indicators. Some states, for example, tliey are less mobile and can be effectively have placed entire orders such as the Plecop- studied by fewer people with less sophis- tera (stoneflies) and Ephemeroptera (may- ticated equipment. flies) on lists or proclamations and have di- On the other hand, politicians and business luted their value. When this is done it people may question the value of an insect. becomes difficult to study these organisms,

Who cares about bugs? How much is a bug because of the problem involved in obtaining really worth? permits and permission to collect specimens. This problem can be illustrated by an in- Collecting alone will probably never se- cident with which I was involved while at riously harm an aquatic insect population, as the Smithsonian Institution. Soon after my has occurred with many butterfly species, but arrival in Washington, D.C., I was asked to habitat manipulation will. look through the aquatic insects for which I was responsible as curator and add^any spe- Literature Cited cies to a list of organisms that could be con- Baumann, R. W. 1976. Amphinemuia reinerti, a new sidered both rare and restricted to the Chesa- stonefly from northern Mexico (Plecoptera: peake Bay area. In Ross and Ricker (1971) I Neniouridae). Southwest. Natur. 20:517-521. foimd a stonefly species, AUocapnio zekia, Baumann, R. W., and a. R. Gaufin. 1972. The Am- phinemiira ventista complex of western North that was known only from the Zekiah America (Plecoptera: Neniouridae). Natur. Hist. Plata, Swamp, La Charles County, Maryland. Mus. Los Angeles Co. Contr. Sci. 226:1-16. I added it to the list and forgot about it. Brown, H. P., and C. M. Murvosh. 1974. A revision of About three years later, I received a tele- the genus Psephenus (Water-Penny Beetles) of the United States and Canada (Coleoptera, Dryo- phone call from a man who wanted to know poidea, Psephenidae). Trans. Amer. Entomol. all about the "Zekiah Stonefly." At first I did Soc. 100: 289-340. not know what he was talking about, but Edmunds, G. F., Jr., S. L. Jensen, and L. Berner. 1976. when he mentioned the Chesapeake Bay spe- The mayflies of North and Central America. Univ. Minnesota Press, Minneapolis. cies list, I remembered. I did some quick re- HoGUE, C. L. 197.3. The net-winged midges or Blepha- search and indicated that the species was riceridae of California. Bull. Calif. Insect Sur. 15: based on a single, male holotype and might 1-83. possibly be a synonym of a widespread east- Jewett, S. G., Jr. 1963. A stonefly aquatic in the adult ern species. He nearly exploded when I re- stage. Science 139: 484-485. 1965. Four new stoneflies from California and ported this to him, because, he said, that "Ze- Oregon. Pan-Pacific Entomol. 41: 5-9. kiah Stonefly" was holding up the Ross, H. H., and W. E. Ricker. 1971. The clas.sification, construction of a water plant in a nearby evolution, and dispersal of the winter stonefly community and was costing a lot of people a genus A//oca^ni«. Illinois Biol. Monog. 45: 1-166. Wi(;r,iNS, B. 1977. Larvae of the North American lot of time and money. G. caddisfly genera (Trichoptera). Univ. Toronto In summary, it is important to understand Press, Toronto, 4 dp. our special environmental here in problems I., L. A. Zhiltzova. 1973. A Zapekina-Dulkeit, J. and North America. If this can be better facil- new genus of stoneflies (Plecoptera) from Lake itated by using aquatic insects, then we Baikal. Entomol. Obozv. 52: 340-345.