262 THOMAS J. WALKER, JR. Ecology, Vol. 38, No. 2 pine barrens may be a limiting factor in the dis- Cain, S. A. 1944. Foundations of plant geography. tribution of anurans. Rana virgatipes and Hyla New York: Harper. andersoni embryos tolerate more strongly acid Collins, W. D., and C. S. Howard. 1927. Quality of the surface waters of New Jersey. U. S. Geol. Surv., solutions than any of the other species tested. Water-Supply Paper 596-E: 89-119. Rana palustris and Acris g. crepitans have the Ellis, M. M. 1937. Detection and measurement of least tolerance to such conditions and these spe- stream pollution. U. S. Bur. of Fish., Bull., 48: 365- cies are practically absent from unaltered pine 437. barrens habitats. Seven of the eleven species Harshberger, J. W. 1916. The vegetation of the New tested require bog water or tap water acidified with Jersey Pine Barrens. Philadelphia: Christopher Sower. hydrocloric acid at at a pH of 4.1 or higher for normal development. Holtfreter, J. 1943. Properties and functions of the surface coat in amphibian embryos. Jour. Exp. Zool., 5. Hyla c. crucifer is capable of spawning suc- 93: 251-323. cessfully in bog water at a pH of 4.2-4.5. Pseud- Krishna, Daya. 1953. Effect of changing pH on de- acris is able to spawn in bog water at pH 4.7, or veloping trout eggs and larvae. Nature, 171 (4349): perhaps even lower. 434. 6. We recognize the probability that additional Krogh, A. 1939. Osmotic regulation in aquatic ani- mals. Cambridge: Univ. Press. factors are involved in limiting the distribution of local Little, S. 1950. Ecology and silviculture of white anurans in the barrens. In fact, it is likely cedar and associated hardwoods in southern New that none of the species is either restricted to or Jersey. Yale Univ. Sch. For., Bull. 56: 1-104. excluded from the pine barrens by the pH factor Love, S. K. 1950. Water quality in the Middle At-- alone. It is possible that for some species, how- lantic States. Jour. Amer. Water Works Ass., 42: ever, pH may have some significance since many 257-265. of the bogs and swamps are too acid for normal Needham, J. 1942. Biochemistry and morphogenesis. Cambridge: Univ. Press. embryonic development to occur. Other physical Nelsen, 0. E. 1953. Comparative embryology of the or chemical factors in the bog water, at present vertebrates. New York: Blakiston. unknown, may have deleterious effects on the em- Noble, G. K. 1926. The hatching process in Alytes, bryos, the larvae, or on the fertilization process Eleutherodactylus and other amphibians. Amer. itself. Mus. Novit., no. 229: 1-7. ,and Ruth C. Noble. 1923. The Anderson tree REFERENCES frog, observations on its habits and life history. Allee, W. C., A. E. Emerson, 0. Park, T. Park, and Zoologica, 2: 417-455. K. P. Schmidt. 1950. Principles of animal ecology. Rugh, Roberts. 1951. The frog. Its reproduction and Philadelphia: Saunders. development. Philadelphia: Blackiston, x + 336 pp. Brachet, J. 19MO. Chemical embryology. New York: Welch, P. S. 1952. Limnology. New York: McGraw- Interscience Publishers. Hill. ECOLOGICAL STUDIES OF THE ARTHROPODS ASSOCIATED WITH CERTAIN DECAYING MATERIALS IN FOUR HABITATS THOMAS J. WALKER, JR. DepartMewt of Zoology and Entomology, Ohio State University, Colhumbus, Ohio INTRODUCTION microclimates) may occur in an area of a few When plants and animals in any habitat die, they acres, the animals associated with similar decaying are set upon by saprophagous organisms. During materials in adjacent habitats may be quite differ- decav there is a succession of organisms associ- ent. ated With the decaying material, that is, the num- Many studies have been made on the arthropods ber and kind of associated organisms change as associated with decaying substances in single hab- decay proceeds. The succession of organisms is itats, but in only a few cases have direct compari- influenced by variations in vegetation and micro- sons of different habitats been made and most of climate. This influence is chiefly through effects these are in the nature of casual observations. on the course of decay and the character of the Jaques (1915) found that Coleoptera are most fauna of the area. Since a great diversity of vege- active at fish "in damp shaded places and resort tational types (and a corresponding diversity of to fish of the sun-heated beach only of necessity." April, 1957 ARTHROPODS OF DECAYING MATERIALS 263 Park (1931) made some general observations on THE HABITATS STUDIED the effect of moisture upon the beetles associated This study is based upon field work done from with fungi. Wialsh (1931, 1933) set carrion-baited June 24 until August 6, 1952, in four habitats of traps in "wood" and "moor" and recorded the differing vegetation about eight miles southeast catch. Kaufman (1937) found that of two carrion- of Camden, Tennessee. Figure 1 shows the exact baited traps in his garden, the one in the moister locations and the topographic relationships of the situation was the more productive. Savelv (1939) habitats. The following general descriptions of studied the successions of animals in oak and pine the vegetation in each of the selected habitats were logs and investigated the microclimate within the substantiated by sampling. decaying logs. Mohr (1943) made an excellent study of the arthropods associated with cattle dung in open pastures. He states that the environment in which the dung is dropped has a profound effect upon its fauna but presents no detailed comparison of differing habitats. Reed (1953) investigated differences in the arthropods associated with dog carcasses in wooded areas and in open pastures. Since comparative studies are so few, this study was undertaken to determine what sorts of sim- 4 ilarities and differences may occur in the arthro- pods associated with decaying materials in differ- ent habitats in the same area. It involves (1) the description of four local habitats in regard to certain aspects of their vegetation and microcli- mate and (2) the analysis of arthropod collections *',....+. ... 03~*'. .|a A from three organic materials placed as baits in each of the four habitats. The writer is indebted to Dr. Arthur C. Cole, Jr. and Dr. Royal E. Shanks for numerous sug- .... ... ...... 'Nt"' gestions in connection with the planning of this R a.. study, and to Dr. Donald J. Borror and Dr. John 1000FT..... N. WVolfefor advice and criticism in the comple- FIG. 1. Topographicmap of study area: 350 58' N Lat., tion of the project and in the preparation of this 88? 04' \N Lon-g. Habitats are indicated by small x's manuscript. The following systematists contrib- within circle. The X on the insert map of Tennessee in- uted freely of their time and skill in the identifica- dicates the general location of the area. tion of the various taxonomic groups encountered Habitat I was located near the mouth of a valley in this study: E. WV.Baker, Acarina; B. D. Burks, draining northeastward. The relatively level val- Hymenoptera; 0. L. Cartwright, Scarabaeidae; ley floor was locally interrupted by shallow drain- R. V. Chamberlin, Myriapoda; E. A. Chapin, age channels. A rich deciduous forest dominated Coleoptera; A. C. Cole, Jr., Formicidae; R. H. by red maple (Acer rubrurn) and sweet gum Foote, Diptera; C. A. Frost, Coleoptera: NV. J. (Liqitidambar styraciflua) formed a tree canopy Gertsch, Araneae; L. R. Gillogly, Nitidulidae; C. with a coverage of about 80% Quercus velhtina, J. Goodnight, Phalangida; J. N. Knull, Coleop- Qutercutsalba, and Nyssa sylvatica were important tera; K. V. Krombein, Hymenoptera; C. F. WV. suhdominiantcanopy species. Commercially valu- Muesebeck, Hymenoptera; Alvah Peterson, im- able trees had been removed from the area about mature insects; C. WV.Sabrosky, Diptera; W.NV. twenty years before. Hazelnut (Corylus amteri- Sanderson, Staphylinidae; R. E. Shanks, flower- cania) and Eitonymtuisamericanuis, together with ing plants; A. J. Sharp, flowering plants: E. L. many young trees, formed a well-developed shrub Sleeper, Curculionidae; WiV.C. Stehr, Carabidae; layer. Ground cover was sparse but varied. A. Stone, Diptera E. S. Thomas, Orthoptera; Habitat II was situated in the flood plain of J. K. Underwood, grasses and sedges; L. MA. Badger Creek, thirty yards north of the creek. Walkley, Ichneumonidae; L. H-. Weld, Hvmienop- That the area was periodically flooded was evi- tera; R. L. Wenzel, Histeridae; NV. NV. NWirth, denced by drift washed against the bases of trees; Diptera; D. L. Wrav, Collembola: and F. N. shallow drainage channels were present. About Young, Hydrophilidae. twenty yards north of the area, the ground rose 264 THOMAS J. WALKER, JR. Ecology, Vol. 38, No. 2 slightly above the level of flooding. A marshy REPLICATE A area associated with Kentucky Lake began thirty yards east. The forest in Habitat II was a park- REPLICATE 0TRAP like stand of large deciduous trees with little shrub C layer and few small trees. Six species were prom- inent in the canopy-Quercus falcata, Quercus MAXIMUM- MINIMUM alba, Liquidambar styraciflua, Carya ovata, Nyssa THERMOMETER sylvatica, and Liriodendron tulipifera. Hornbeam X (Carpinus caroliniana) formed a relatively con- 0 tinuous tree understory, even predominating over RAIN GAUGEW-52 * 0 the canopy species in basal area (about 20%) and in number of stems (about 45%). There was no evidence of lumbering. Grasses and sedges were markedly dominant in the sparse ground cover. Habitat III was on a SE-NW ridge approxi- mately forty yards wide and with steep sides. The forest canopy in Habitat III was quite broken, having a coverage of only about 30%. Post oak 04 d/ REPjCp B (Quercus stellata) and white oak (Quercus alba) _ were the dominants. Quercus marilandica, Quer- FIG. 2. Sample experimental setup of a trap circle. cus coccinea., Quercus velutina, and Carya glabra Numbers by traps refer to baits: 1-check; 2-cornmeal; were important subdominants.