Abstract

In this study of the genitalia and spermathecae of the Rhynohophora, eighty-two species, representing sixty genera, were examined as listed in Leng's Catalogue of Coleoptera of North America North of Mexico, together with seven species from the Phillippine Islands and one from China. By using the external female genitalia and spermathecae the Rhynochophora studied may be divided into eight and possibly nine well-defined groups. They are separated into these groups on the basis of the development of the nodulus and ramus and upon the degree of crenulation that occurs in the spermatheca. The spermatheca of all species studied has been figured, but it was beyond the scope of this study to make drawings of all the external female genital structures. I have therefore figured the genitalia of only a few of the species dealt with in this study. The Rhynochophora examined have sustantiated, with few exceptions, the arrangement followed in Leng's Catalogue of Coleoptera and Boving's study based on the larval forms. No final conclusions have been reached regarding the taxonomy and phylogeny of the Rhynochophora but only the results from a study of the female genitalia and spermathecae. The evolution of the genitalia has been from the complex to the simple structures, the Brentidae and Platystomidae are the most primitive and the Scolytidae are the most recent. The spermathaca appears to have evolved from the simple to the complex and then back to the simple form. The specific characters of these structures are very useful guides and should be utilized in future taxonomic work. They are of value in generic as well as specific separation. Where closely related species of the same genus were investigated, notable differences were found in the genitalia and spermatheca. In this paper one hundred and seventeen drawings have been included to show the value of the genitalia nd spermatheca as a medium for identification of the different species.

Degree

College and Department

Life Sciences; Plant and Wildlife Sciences

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