Unusual Habitats

Because of adaptive radiation over evolutionary time, insects have colonized virtually every aquatic habitat on earth. Therefore, it is not surprising that these organisms are found

TABLE V Summary of Ecological Data for Benthic Aquatic and Semiaquatic Diptera Larvae Inhabiting Lentic Habitats

Family

Ceratopogonidae (biting midges, "no-see-ums")

Chironomidae (nonbiting midges)

Corethrellidae Psychodidae (moth flies)

Ptycopteridae (phantom crane flies)

Tipulidae (crane flies)

Dolichopodidae

Stratiomyidae (soldier flies)

Tabanidae (horseflies, deerflies)

Canacidae (beach flies) Ephydridae (shore and brine flies)

Muscidae

Scathophagidae (dung flies) Sciomyzidae (marsh flies) Syrphidae (flower flies)

Habitat

Littoral zone (including tree holes and small temporary ponds and pools) All lentic habitats including marine, springs, tree holes

Limnetic and littoral margins Littoral detritus (including tree holes) Vascular hydrophytes (emergent zone), bogs Littoral margins, floodplains

(organic sediment) Littoral margins, estuaries, beach zones Littoral vascular hydrophytes;

beaches (saline pools, margins) Littoral (margins, sediments and detritus); beaches, marine and estuary Beaches—marine intertidal Littoral (margins and vascular hydrophytes)

Littoral

Vascular hydrophytes

(emergent zone) Littoral—vascular hydrophytes

(emergent zone) Littoral (sediments and detritus), tree holes

Habitat

Generally sprawlers, burrowers or planktonic (swimmers)

Generally burrowers, sprawlers (most are tube builders); some climber-clingers Sprawlers Burrowers

Burrowers

Burrowers and sprawlers Sprawlers, burrowers Sprawlers

Sprawlers, burrowers Burrowers

Burrowers, sprawlers Sprawlers

Burrower-miners (in plant stems), sprawlers

Burrowers, inside snails Burrowers

Functional feeding mode

Generally predators some collector-gatherers

Generally collector-gatherers, collector-filterers; some shredders and scrapers Predators

Collector-gatherers Collector-gatherers

Generally shredders, collector-gatherers Predators

Collector-gatherers Predators

Scrapers

Collector-gatherers, shredders, herbivores (miners), scrapers, predators Predators Shredders

Predators or parasites Collector-gatherers in the most unusual of aquatic habitats. The title of most versatile aquatic insect must be shared among members of the dipteran family Ephydridae, or shore flies. Shore flies can breed in pools of crude petroleum and waste oil, where the larva feed on insects that become trapped on the surface film. Other species of this family (Ephydra cinera), known as brine flies, occur in the Great Salt Lake, Utah, which has a salinity six times greater than that of seawater. Larva maintain water and salt balance by drinking the saline medium and excreting rectal fluid that is more than 20% salt. Another related family of flies, the Syrphidae, or "rat-tailed maggots," occur in sewage treatment lagoons and on moist substrates of trickling filter treatment facilities. Both families have larvae with breathing tubes on the terminal end, which permits the larvae to maintain contact with the air while in their environment. Some Stratiomyiidae, or soldier flies, live in the thermal hot springs of Yellowstone National Park with temperatures as high as 47°C! Other members of this family inhabit the semiaquatic medium of cow dung and dead corpses. A few species of insects have invaded caves and associated subterranean habitats, as mentioned earlier (see Lotic Habitats).

Another unsual aquatic habitat that several insect orders occupy is referred to phytotelmata or natural container habitats and include tree holes, pitcher plants, bromeliads, inflorescences, and bamboo stems. Synthetic container habitats, such as old tires, cemetery urns, rain gutters, and similar natural habitats such as hoofprints also harbor similar insects. Some of these habitats are extremely small and hold water only temporarily, but nevertheless can be quite diverse. The most common order found in these habitats is the Diptera with more than 20 families reported. Over 400 species of mosquitoes in 15 genera alone inhabit these bodies of water and some of these species are important vectors of disease agents.

Insect communities inhabiting pitcher plants (Sarracenia purpurea) in North America are exemplified by a sarcophagid or flesh fly (Blaesoxipha fletcheri), a mosquito (Wyeomyia smithii), and a midge (Metriocnemus knabi). The relative abundance of these pitcher plant inhabitants is related to the age, inasmuch as each of the three species consumes insect remains that are in different stages of decomposition. Specifically, the larvae of the flesh fly feed on freshly caught prey floating on the pitcher fluid surface. The mosquito larvae filter feed on the decomposed material in the water column, and the midge larvae feed on the remains that collect on the bottom of the pitcher chamber. Temporary habitats are important because they are populated by a variety of species, often with unique morphological, behavioral, and physiological properties.

See Also the Following Articles

Cave Insects • Marine Insects • Mosquitoes • Soil Habitats • Swimming

Further Reading

Allan, J. D. (1995). "Stream Ecology." Kluwer, Dordrecht, the Netherlands. Bronmark, C., and Hansson, L.-A. (1998). "The Biology of Lakes and

Ponds." Oxford University Press, Oxford, U.K. Cummins, K. W. (1973). Trophic relations of aquatic insects. Annu. Rev.

Entomol. 18, 183-206. Cushing, C. E., and Allan, J. D. (2001). "Streams: Their Ecology and Life."

Academic Press, San Diego, CA. Hynes, H. B. N. (1970). "The Ecology of Running Waters." University of

Toronto Press, Toronto, Ont., Canada. McCafferty, W. P. (1981). "Aquatic Entomology." Jones & Bartlett, Boston. Merritt, R. W., and Cummins, K. W. (eds.). (1996). "An Introduction to the

Aquatic Insects of North America." Kendall/Hunt, Dubuque, IA. Merritt, R. W., and Wallace, J. B. (1981). Filter-feeding in aquatic insects.

Sci. Am. 244, 131-144. Resh, V. H., and Rosenberg, D. M. (1984). "The Ecology of Aquatic

Insects." Praeger Scientific, New York. Ward, J. V. (1996). "Aquatic Insect Ecology," Vol. 1, "Biology and Habitat." Wiley, New York.

Williams, D. D. (2002). "The Ecology of Temporary Waters." Blackburn

Press, Caldwell, NJ. Williams, D. D., and Feltmate, B. W. (1992). "Aquatic Insects." CAB International, Wallingford, Oxon, U.K.

0 0

Post a comment