Immunologic Comparisons of Selected Coleoptera With Analyses of Relationships Using Numerical Taxonomic Methods

Abstract

The status of the cicindelids with respect to the carabids (Coleoptera) is an issue among taxonomists. Data from immunoelectrophoresis and immunodiffusion were processed using detailed computerized, numerical taxonomic methods which included cluster and principal components analyses. Results indicated that the cicindelids are preferably regarded as a subfamily of the family Carabidae. The genera in the family Carabidae exhibited large amounts of molecular variation. In detailed comparisons, using the computer, unstandardized logarithms of the per cent cross-reaction values gave the highest correlations of the immunological data with morphological classifications of the Coleoptera. In the Coleoptera the status of the cicindelids (tiger beetles) with respect to the carabids (ground beetles) and to the suborder Adephaga is still an issue among taxonomists. A number of taxonomists, including LeConte and Horn (1883), Blatchley (1910:25-242, 247-270), Leng (1920: 39-86, 157, 235, 255), Portevin (1929), Bradley (1930:307-325), Jeannel (1949: 1032-1069), Borror and DeLong (1954:296426), and Ball (1963:55-182, personal communication in 1966 and 1968), consider the cicindelids as a separate family; others, such as Hatch (1938:225-240), Crowson (1955), Moore (1958), Linssen (1959:51157 [series 1], 70-122 [series 2] ), and Bell (1967), place the tiger beetles in a subfamily, Cicindelinae, of the family Carabidae. For the purpose of discussion in this paper, we shall refer to the carabids and cicindelids as separate families. Taxonomic investigations in the class Insecta, using immunological techniques, are few in number and have been concerned mostly with orders in the subclass Pterygota. Although beetles have been used incidentally in several immunotaxonomic studies, the work of Butler and Leone (1967b) was the first study dealing exclusively with a wide variety of coleopterans. They observed that, with certain exceptions, the immunological classification of beetles confirmed morphological classifications. Butler (1965) encountered inconsistencies and ambiguities when performing immunological comparisons of carabids and cicindelids. Such findings prompted this investigation, and the work here reported re-examines the carabid-cicindelid relationship. Data were obtained from an extensive series of immunological comparisons of saline extracts of adults from 11 species in the families Carabidae and Cicindelidae. Species from six other families, including two dytiscids, three hydrophilids, and one each from the families Tenebrionidae, Gyrinidae, Scarabaeidae and Meloidae were chosen to provide taxonomic references for comparisons with the carabidcicindelid relationship. Numerical taxonomic methods, including cluster and principal components analyses, were used. METHODS AND MATERIALS The specimens used in this study were collected in the vicinity of Lawrence, Kansas, except Tenebrio, which was cultured in the laboratory. The beetles were kept alive and unfed 24 to 48 hours prior to processing in the laboratory to permit the digestion of any food in the gut, then were quick-frozen and stored at -150C in airtight containers until needed for homogenization.