THE ORB WEAVER GENUS NEOSCONA IN NORTH AMERICA (ARANEAE: ARANEIDAE) JONATHAN D. BERMAN* AND HERBERT W. LEVI ABSTRACT The number of Nortli American Neoscona spe-cies has been reduced to ten. Characters of the male palpus, the epigynmn, and the dorsal ab-dominal pattern have been found useful in species diagnosis. There are keys to tlie species, and the distributions have been mapped. Although Neoscona species are among the most common spiders in North America and species are found throughout most parts of the world, no thorough study of the group has ever been made. The most important works dealing with the genus are those of F. O. P.-Cambridge (1904), who first recognized several North Amer-ican species and included detailed de-scriptions of a number of others, and Archer (1941), who listed many of the North American species but did not give any indication of how he was able to separate them. Because Neoscona includes common spiders, the problem of determining speci-mens frequently arises in ecological studies. In addition, members of the genus have sometimes been used as laboratory ani-mals. For these reasons it is important that * This study was started as a senior thesis for Harvard College by J. D. B. The object vi^as to find characters that can be used in separating species of the genus. The cliaracters carefully studied were coloration and pattern, size, epigy-num, and spination of the second tibia of males. The palpi of the species separated by these criteria were later studied in detail by H. W. L. and nomenclatural problems resolved. reliable characters for separating the spe-cies be found. While it is easy to find differences be-tween individual specimens of Neoscona, it is far more difficult to find similarities that reflect the common gene pool of species. In this investigation it was found that the most dependable character for separating females of the genus is the epigynum together with the color pattern. Details of the palpus are the best char-acters for distinguishing males; the macro-setae of the second tibia are not always reliable. Ten species of North American Neoscona were segregated on the basis of these and other characters. Most specimens in col-lections can readily be placed in one of these species and between the species there are gaps in the characters used. Occasional specimens are difficult to determine, per-haps because poor preservation removed the color pattern, and because of abnor-malities or, perhaps, hybridization. Dr. J. A. L. Cooke made available the collections of both the American Museum of Natural Histoiy and Comell Universit)', Dr. C. D. Dondalc, the collections of the Canadian National Museum. Other Cana-dian collections were supplied b\-D. J. Buckle. Dr. H. K. Wallace loaned large collections from Michigan and Florida with ecological data, and Dr. W. Shear pro-vided specimens and other help. Dr. H. V. Weems sent specimens from the Florida State Museum. Dr. M. Grasshoff loaned Bull. Mas. Comp. Zool., 141(8): 465-500, September, 1971 465
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