Dicaelus (Dicaelus) alternans Dejean 1826

Dicaelus alternans Dejean
In addition to the characters presented in the key, the disc of the pronotum of alternans is more convex than is that of the preceding species. This species is here regarded as being ditypic, composed of the nomotypical subspecies, and a. subtropicus Casey. These two forms are identical with respect to structure of the male genitalia. Both have the same type of pronotum and both have short setae scattered over the surface of the elytra, a characteristic peculiar to them in the genus Dicaelus. They differ in that alternans is larger in size (see tables 4041) on the average, with elytral intervals 3 and 5 more convex, appreciably wider (see table 42), more opaque, with more setae scattered over the surface. Subtropicus averages smaller in size, with elytral intervals all of about the same convexity, 3 and 5 wider than 1, 2, 4, and 6, but not as much as the typical subspecies, and the former are not more opaque, and have only a very few or no setae on their surface. In addition to the morphological data which seem to indicate a close alliance between them, alternans and subtropicus are allopatric. Specimens of alternans are not known from south of the southern tip of Lake Okeechobee, in Florida, and, conversely, specimens of subtropicus have been found only in localities which are south of the latitude of Lake Okeechobee.