Comparative Ethology and the Systematics of Spider Wasps

Abstract

GOMPARATIVE anatomy has always been the major wellspring of taxonomic data. For practical reasons it probably will always remain so. A curator cannot be expected to identify and arrange his collections on the basis of chromosome number, serum agglutinations, and behavior during courtship. Keys will always be by-products of taxonomic investigations, and keys must always be based largely on morphological characters, preferably external ones. But they are only by-products. In his studies of the natural relationships of organisms and in his attempts to interpret the patterns of within groups, the systematist must avail himself of all possible sources of data. Once he has arrived at certain conclusions, it may then be possible to re-evaluate the morphological characters in such a way as to present a key which will be useful and yet far more meaningful than one compiled hurriedly for purposes of identification. If this is not possible, progress has still been made toward a classification which more nearly approximates the ideal, even though it may still be necessary to depend upon artificial keys for identifying specimens. inconvenience of using ethological characters in classification is obvious: one must work with living specimens in their normal habitat or under conditions closely resembling their normal habitat. It would be impossible to maintain, however, that behavioral characters are less important than structural characters; indeed, it would be easier to maintain that the reverse were true. It has been stated recently that biological characters are of paramount importance to the classifier, for habits and behavior are certainly deeply rooted and are often the product of a very ancient evolution (Delacour and Mayr, 1945, p. 49). In his admirable essay on The Comparative Method in Studying Innate Behaviour Patterns, Lorenz (1950, pp. 239-240) states: