Calligrapha

Gómez-Zurita, Jesús, 2015, Systematic revision of the genus Calligrapha Chevrolat (Coleoptera: Chrysomelidae, Chrysomelinae) in Central America: The group of Calligrapha argus Stål, Zootaxa 3922 (1), pp. 1-71 : 6-7

Key to main species groups in Calligrapha

The current study focuses on a single important group of species typical from Central America, the Calligrapha argus group. I was able to diagnose the group in the context of the whole phenotypic diversity represented by species currently recognized as part of Calligrapha . Below I provide a tentative, pragmatic key to recognize the main morphological groups in Calligrapha based on characters easy to distinguish, mostly on elytral designs. These characters are not to be confused with colour variation, which may be perceived as an inferior character for taxonomic assessment, due to colour polymorphisms known to reflect intraspecific variation or response to environmental factors in many insects ( Quicke 1993, p. 38). Elytral patterns in Calligrapha represent in fact several complex structural characters which proved to have strong systematic value, given their covariation with other character systems, and also confirmed based on preliminary molecular phylogenetic results ( Montelongo & Gómez-Zurita 2014). For the nomenclature and positions of elytral markings, I refer to Gómez-Zurita et al. (2004) and Montelongo & Gómez-Zurita (2013).

1 Claws fused at base ( Fig. 2 a). Nearctic and Central American group............... Group of C. (Zygospila) suturalis (F.)

- Claws divergent at base ( Fig. 2 b). Nearctic and Neotropical groups.............................................. 2

2 Hypomeral suture obliterated ( Fig. 2 c) and elytra striped ( Fig. 2 e)............................................... 3

- Hypomeral suture deep, running nearly parallel ventrally to pronotal margin ( Fig. 2 d) or if obliterated, then elytra spotted ( Fig. 2 f)................................................................................................. 4

3 Last maxillary palpomere subquadrate, at least as wide as apex of previous palpomere. Penis broad, with conspicuous median tooth at apex. Distributed in North America, north of Mexico........................... Group of C. bidenticola Brown

- Last maxillary palpomere oblong, longer than wide and clearly narrower than apex of previous palpomere. Penis slender, with rounded apical end. Distributed in South America...................................... Group of C. curvilinea Stål

4 Pattern of pale spots on dark background ( Fig. 2 g). Central American species only, from Mexico to Nicaragua. (One species in North America with pale spots, C. pnirsa Stål , belongs to the C. philadelphica group).................................................................................................... Group of C. vigintimaculata (Chevrolat)

- Pattern of dark spots on pale background ( Fig. 2 h).......................................................... 5

5 Two spots enclosed by humeral lunule, longitudinally arranged ( Fig. 2 j). Distal end of flagellum of transversal U-shaped pro- file ( Fig. 1 d). Species present in Central America, from Mexico to Panama................. Group of C. labyrinthica Stål

- Spot enclosed by humeral lunule simple ( Fig. 2 i). Distal end of flagellum shaped differently......................... 6

6 Subhumeral spot present ( Fig. 2 k). Distal end of flagellum as flattened disc with central orifice ( Fig. 1 c). Species in the south- ern Nearctic and Neotropical regions, from Mexico to Argentina....................... Group of C. polyspila (Germar)

- Subhumeral spot absent ( Fig. 2 l). Distal end of flagellum with deep V-shaped or U-shaped ventral emargination ( Figs 1 a, 1b).................................................................................................... 7

7 Hypomeral suture deep, running nearly parallel to pronotal border ( Fig. 2 d)...................................... 8

- Hypomeral suture obliterated ( Fig. 2 c). Distributed in North America, north of Mexico...... Group of C. philadelphica (L.)

8 Striped elytra ( Fig. 2 e). Western Nearctic species................................... Group of C. dislocata (Rogers)

- Spotted elytra, with pattern of dark spots on pale background ( Fig. 2 f). Species in the southern Nearctic and Neotropical regions, from southern USA to Venezuela................................................ Group of C. argus Stål

Figures

FIGURE 1. Schematic representations of the typical apical ends of flagella in the penis of species in the Calligrapha argus group (a), in the C. dislocata and C. philadelphica groups (d), in the C. polyspila group (c), and in the C. labyrinthica group (d).

FIGURE 2. Distinguishing traits of major Calligrapha lineages: (a) connate claws of Calligrapha (Zygospila) mexicana Jacoby; (b) divergent claws of C. labyrinthica Stål; (c) unimpressed hypomera in C. percheroni Stål; (d) hypomera with impressed suture in C. argus Stål (white arrowhead); (e) habitus of C. californica Brown showing striped elytral pattern; (f) habitus of C. amelia Knab showing spotted elytra; (g) habitus of C. vigintimaculata (Chevrolat) showing reversed contrasting pattern of pale markings on dark background; (h) habitus of C. serpentina (Rogers) showing typical pattern of dark markings on pale background; (i) left elytron of C. sponsa Stål with a single spot enclosed by humeral lunule (white arrowhead); (j) left elytron of C. aladina Bechyné with arrangement of two spots enclosed by humeral lunule (white arrowheads); (k) left elytron of C. polyspila (Germar) with subhumeral (white arrowhead) and midlateral (black arrowhead) spots; and (l) left elytron of C. multipustulata Stål only with midlateral spot (black arrowhead).