Tragidion

Swift, Ian & Ray, Ann M., 2008, A review of the genus Tragidion Audinet-Serville, 1834 (Coleoptera: Cerambycidae: Cerambycinae: Trachyderini), Zootaxa 1892, pp. 1-25 : 22-23

Key to the females of Tragidion species

Within this key, T. coquus will key out in two different couplets, due to the variability of phenotypes. Populations from western and central Texas do not key out well (see discussion). It should be noted that females Tragidion are very difficult to key and the distinguishing characters among species groups are often very weak.

1 Elytral surface with elevated costae, surface appearing corrugated........................................................2

1’ Elytral surface with smooth striae, not appearing elevated .................................................................... 7

2(1) Elytron with 5 costae..............................................................................................................................3

2’ Elytron with 4 costae..............................................................................................................................4

3 (2) Elytra dark orange, costae somewhat curved inward to suture ( Fig.3 E) ................................ desiventre

3’ Elytra yellow-orange, costae generally straight from base to apex ......................................................11

4(2’) Antennae not annulated in orange............................................................................................................9

4’ Antennae with at lease some antennomeres annulated in orange............................................................5

5(4’) Elytra with broad dark basal band exceeding the scutellum by 2 × its length or more; costae terminating ½ to apex; ventral surface with dull blue reflections ( Fig. 3 C) .............................................. .. deceptum

5’ Elytra with narrow dark basal band not or just attaining scutellum; costae terminating at apex or nearly so; ventral surface with bright metallic blue reflections ( Fig. 1 D) ........................................ annulatum

6(1’) Body elongate and narrow greater than 3 × as long as wide (at humeri); ventral, head, and metafemoral pubescence with distinct metallic blue reflections ( Fig. 2 D)......................................................... bicolor

6’ Body robust, less than 2.5 × as long as wide; ventral, head, and metafemoral pubescence without metal- lic blue reflections...................................................................................................................................7

7(6’) Metatarsi slender, the 1st tarsomere longer than the following two together, and the 2nd tarsomere longer than broad and distinctly more elongate than the 3rd; scape robust, greater than 2 × the width of the 2nd antennomere at apex ( Fig. 4 C) ................................................................................................... gracilipes

7’ Metatarsi robust, the 1st tarsomere almost as long as broad, not as long as the following 2 tarsomeres; scape not as robust, less than 1.5 × the width of the antennomere 2 at apex............................................8

8(7’) Antennae attaining the apical ¾ of elytra or greater; pronotal pubescence sparse on frons and pronotal

disk ( Fig. 1 B) ................................................................................................................................. agave 8’ Antennae attaining basal % of elytra or less; integument of head, legs, and pronotum black; pronotal pubescence black, dense on frons and pronotal disk ( Fig. 1 F) ................................................. armatum 9(4) Antennomeres 5–7 producing a distinct, recurved apical spine; pronotal pubescence dense, short and appressed ( Fig. 4 A) .......................................................................................................... dichromaticum

9’ Antennomeres, 5–7 not producing distinct, recurved apical spine; pronotal pubescence long, erect .. 10

10(9’)Elytral costae terminating at ½ to apex; dark basal band exceeding the scutellum by at least 2 × its length ......................................................................................................................................... carinatum

10’ Elytral costae attaining the apex or nearly so; dark basal band just attaining the scutellum, if absent, elytra generally entirely infuscated ( Fig. 3 A) ................................................................................ coquus

11(3’)Scape expanded apically, generally small species ( Fig. 2 B)..................................................... auripenne

11’ Scape equilateral, generally large, robust species ( Fig. 3 A).......................................................... coquus

Figures

FIGURE 1. Dorsal habitus photos of Tragidion spp. A, Tragidion agave (male); B, T. agave (female); C, T. annulatum (male); D, T. annulatum (female); E, T. armatum (male); F, T. armatum (female).

FIGURE 2. Dorsal habitus photos of Tragidion spp. A, Tragidion auripenne (male); B, T. auripenne (female); C, T. bicolor (male); D, T. bicolor (female); E, T. coquus (male); F, T. coquus (male).

FIGURE 3. Dorsal habitus photos of Tragidion spp. A, Tragidion coquus (female); B, T. deceptum (male); C, T. deceptum (female); D, T. densiventre (male); E, T. densiventre (female); F, T. dichromaticum (male).

FIGURE 4. Dorsal habitus photos of Tragidion spp. A, Tragidion dichromaticum (female); B, T. gracilipes (male); C, T. gracilipes (female).