Ceratophila

Tang, William, Skelley, Paul & Pérez-Farrera, Miguel Angel, 2018, Ceratophila, a new genus of erotylid beetles (Erotylidae: Pharaxonothinae) inhabiting male cones of the cycad Ceratozamia (Cycadales: Zamiaceae), Zootaxa 4508 (2), pp. 151-178 : 155-156

Key to adult Ceratophila

Because of variable and overlapping morphological character states with some species, it is desirable, and in some cases necessary, to have a series of specimens representing color variations and both sexes to properly identify a

species. In the following key, text in brackets before the species name are the Mexican states of occurrence and the known host species of Ceratozamia .

1. Pronotum not explanate laterally, surface convexly curved to lateral carinae; lateral carinae in lateral view distinctly thicker anteriorly, anterior thickness 2× posterior thickness ( Fig. 1D); pronotal disc lacking longitudinal groove extending anteriorly from lateral basal pore in margin ( Fig. 1B); metatibia triangularly dilated toward apex ( Fig. 1F)......................................................................................... [subgenus Ceratophila, new subgenus ] ... 2

- Pronotum explanate laterally, surface broadly concave near lateral carinae; lateral carina weakly thickening anteriorly, anterior thickness <1.5× that at base ( Fig. 1E); pronotal disc with longitudinal groove extending anteriorly from lateral basal pore in margin ( Fig. 6D); metatibia not triangularly dilated toward apex ( Fig. 1G)............... [ Vovidesa , new subgenus] … 5

2(1). Head with broad medial transverse ridge anterior of a distinct transverse basal groove in males ( Fig. 2D), ridge and groove weak in females, ridge interrupting supraocular line in both male and female; head broad, width = 0.74–0.75× pronotal width; anterior clypeal margin emarginate; pronotal hypomeron densely punctate ( Fig. 2E); [Veracruz— C. euryphyllidia ].................................................................................... C. (C.) chemnicki , new species

- Base of head at most with indistinct shallow transverse groove, supraocular line complete ( Fig. 3D); head narrower, width = 0.66–0.68× pronotal width; anterior clypeal margin truncate or weakly convex; pronotal hypomeron with punctures sparse and minute or lacking ( Fig. 3E).............................................................................. 3

3(2). Dark elytral markings (when present) laterally covering most of disc ( Fig. 4A); pronotum generally more elongate, pronotal length/pronotal width (PL/PW) = 0.83–0.90; [Chiapas— C. alvarezii , C. mirandae , C. norstogii , C. vovidesii ]......................................................................................... C. (C.) picipennis , new species

- Dark elytral markings (when present) only along suture and laterally ( Fig. 5A); pronotum generally shorter, PL/PW = 0.80– 0.84................................................................................................ 4

4(3). Color of pronotum and elytra similar ( Fig. 5A); pronotum generally more quadrate; male genitalia with penile struts relatively long, length of penile strut relative to median lobe 2:1; setae at apex of parameres with greatest length <dorsal width of parameres ( Fig. 5F); [Veracruz— C. tenuis ]......................................... C. (C.) sanchezae , new species

- Pronotum reddish brown contrasting with light brown of elytra ( Fig. 3A); pronotum generally more trapezoidal, narrowing anteriorly; male genitalia with penile struts shorter, length of penile struts relative to median lobe 3:2; setae at apex of parameres with greatest length ± dorsal width of parameres ( Fig. 3H); [Oaxaca— C. mixeorum ]...................................................................................................... C. (C.) gregoryi , new species

5(1). Male meso- and metatibiae each with medial subapical emargination ( Fig. 1G); female abdominal segments weakly alutaceous, punctures and setae visible except on lateral quarters.................................................... 6

- Male tibiae lacking medial subapical emargination; female abdominal segments strongly alutaceous ( Fig. 6B), punctures obscured across middle, setae reduced [Chiapas— C. alvarezii , C. mirandae , C. norstogi , C. vovidesii ]............................................................................................... C. (V.) chiapensis , new species

6(5). Submentum of male and female with sparse patch of setae-bearing punctures, male with long setae projecting anteriorly ( Fig. 7E); male genitalia more dorsoventrally compressed, median lobe nearly cylindrical; [Veracruz— C. mixeorum ]........................................................................................ C. (V.) mixeorum , new species

- Submentum of male and female with dense patch of setae-bearing punctures, male with long setae projecting laterally ( Figs. 8 E–F); male genitalia laterally compressed, median lobe laterally flattened and distinctly curved in lateral view; [Veracruz— C. tenuis ]....................................................................... C. (V.) vazquezi , new species