Cymatodera balteata

Burke, Alan F. & Zolnerowich, Gregory, 2014, Cymatodera ochlera Barr, a junior synonym of Cymatodera wolcotti Barr, with a comparison to similar species (Coleoptera: Cleridae), Zootaxa 3847 (3), pp. 423-430 : 428-429

Cymatodera balteata and C. undulate

These species have been traditionally considered closely allied to C. wolcotti , and some specimens examined as part of this study were incorrectly identified as C. ochlera or C. wolcotti . Therefore, it is useful to present morphological characters that will serve to separate these species, and evaluate the relationships these species have with C. wolcotti .

Specimens of C. balteata and C. undulata were clearly different from the C. ochlera / C. wolcotti complex. Differences in male abdominal segments and aedeagus are as follows: C. balteata displays the sixth visible ventrite as long as wide, feebly extending beyond lateral margins of the sixth tergite, the lateral margins subparallel, and the posterolateral angles pointed distally, not produced ( Fig. 13 ); C. wolcotti has the sixth visible ventrite wider than long, the lateral margins strongly oblique, conspicuously extending beyond lateral margins of the sixth tergite, and the posterolateral angles procurved and extended, this extension ranges from folded inward (arrows, Fig. 15 ) to moderately extending forward (arrows, Fig. 16 ), to extending posteriorly (arrows, Fig. 17 ). The sixth tergite of C. balteata has the posterolateral angles robust and procurved outward, and the posterior margin truncate, notched medially ( Fig. 9 ); C. wolcotti has the posterior margin of the sixth tergite feebly to moderately procurved inward (arrows, Fig. 11 ) and the posterior margin moderately emarginate. For differences in male genitalia, C. balteata has the parameres triangular, somewhat slender distally and gradually widening anteriorly, rather rounded at apex; copulatory piece folded upward; phallus moderately robust; tegmen fully covering phallus and distally emarginate ( Fig. 5 ). The male genitalia of C. wolcotti has the parameres subtriangular in shape, lateral margins moderately to strongly sinuate, pointed at apex; copulatory piece straight and partially covered by tegmen; phallus moderately robust; the tegmen is covering approximately 1/3 the length of phallus and it is not emarginate distally ( Fig. 8 ).

Only minor differences in elytral color, fasciae pattern, and size were observed in C. balteata . Brachypterous specimens of both sexes were commonly observed for this species, and specimens with normal hind wings were less frequent among the specimens examined ( Figs. 19, 20 ). Those specimens with a brachypterous state also displayed a reduced anterior elytral margin compared with specimens possessing fully developed hind wings (compare A, B in Figs. 19-20 ). In the order Coleoptera , flight muscles are located in the metathorax, covered to a great extent by the scutum; thus, the reduction of the anterior elytral margin in various Cymatodera species, including C. balteata , is accompanied by the reduction of the scutum, wing muscles, and wing size. The ecological implications of brachyptery in various species of Cymatodera is unknown, but could be an adaptive strategy to allocate the energy traditionally used in the development of flight muscles and during flight, to other purposes, such as reproduction.

Specimens of C. undulata have the posterolateral angles of the sixth tergite curved outward and the posterior margin broadly truncate ( Fig. 12 ); C. wolcotti has the posterolateral angles of the sixth tergite moderately procurved inward and the posterior margin subtriangularly emarginate, with a somewhat deep, longitudinal median carina that reaches the anterior margin ( Fig. 11 ), this carina is absent in C. undulata ; the sixth visible ventrite of C. undulata is longer than broad, feebly extending beyond the lateral margins of sixth tergite, surface convex, posterolateral angles rounded, posterior margin broadly truncate ( Fig. 18 ); C. wolcotti has the sixth visible ventrite longer than wide, conspicuously extending beyond the lateral margins of the sixth tergite, surface concave, the lateral margins are strongly oblique anteriorly and feebly to moderately sinuate posteriorly, the posterolateral angles are extended, this extension ranges from folded inward (arrows, Fig. 15 ) to extended posteriorly (arrows, Fig. 17 ). Male genitalia of these two species are as follows: C. undulata has the aedeagus robust, the parameres are conspicuously triangular; strongly slender distally and gradually widening anteriorly, pointed at apex, copulatory piece is rounded distally, tegmen is reduced, partially covering phallus, leaving approximately one half of the phallus exposed, moderately emarginate distally, phallic plate unsuspiciously armed with few denticles irregularly arranged; and the phallobasic apodeme is slender distally ( Fig. 8 ). Cymatodera wolcotti has the aedeagus moderately slender; the parameres are subtriangular, with the lateral margins moderately to strongly sinuate, feebly to moderately pointed at apex; the copulatory piece is pointed distally; tegmen moderately covering phallus, leaving approximately one half of the phallus exposed, distal emargination absent; phallic plate armed with two rows of denticles, denticles gradually reducing in size toward apex; and phallobasic apodeme robust distally ( Fig. 7 ).

Based on the evidence presented here, Cymatodera ochlera and C. wolcotti are conspecific, and C. ochlera should be considered a junior synonym of C. wolcotti . Despite morphological similarities and partially overlapping populations, C. balteata and C. undulata are distinct and separate species. Morphological structures suggest C. undulate is less related to C. balteata and C. wolcotti than originally believed. A less differentiated sixth abdominal segment ( Figs. 11–12, 15–18 ), more robust male genitalia, the absence of a developed row of denticles, stout parameres, a distally slender phallobasic apodeme, and a shorter tegmen in relation to the length of the aedeagus ( Figs. 5–8 ) serve as evidence to indicate a rather distant relationship this species has with the closely allied C. balteata and C. wolcotti . Finally, it should be noted that variation in color and pattern of the elytra or habitus has proven to be of insufficient diagnostic significance when characterizing this genus.

Figures

FIGURES 9 – 18. Sixth abdominal segment of: 9 Cymatodera balteata (male, dorsal view); 10 C. ochlera (male, dorsal view); 11 C. wolcotti (male, dorsal view); 12 C. undulata (male, dorsal view); 13 C. balteata (male, ventral view); 14 C. ochlera (male, ventral view); 15 C. wolcotti (male, ventral view); 16 C. wolcotti paratype (male, ventral view); 17 C. wolcotti (male, ventral view); 18 C. undulata (male, ventral view). For Figs. 10 – 11, arrows indicate curvature of posterolateral margins. For Figs. 14 – 17, arrows indicate direction of hind angles.

FIGURES 5 – 8. Male genitalia of: 5 Cymatodera balteata; 6 C. ochlera; 7 C. wolcotti; 8 C. undulata.

FIGURES 19 – 20. Dorsal views of Cymatodera balteata indicating: 19. A width of anterior margin of right elytron; B length of wing. 20. A width of anterior margin of right elytron. B length of wing.