Cyllodes thomasi Cline and Skelley

Cline, Andrew R. & Skelley, Paul E., 2013, Discovery of new species and country records for the North American sap beetle fauna (Coleoptera: Nitidulidae), Zootaxa 3683 (2), pp. 101-116 : 104-108

Cyllodes thomasi Cline and Skelley , n. sp.

( Figs. 2–10 )

Specimens examined. Holotype (FSCA) Arizona: Santa; Rita Mts.; Madera Cyn.; Aug. 3 1968 / gilled fungus; K.

Stephan leg. / HOLOTYPE; Cyllodes ; thomasi ; Des. 2012 Cline and Skelley [the “gilled fungus” portion of the second label is handwritten on this label and all subsequent paratype labels with the same phrase].

Paratype— 1 specimen: (ARCC) Arizona: Santa; Rita Mts.; Madera Cyn.; Aug. 3 1968 / gilled fungus; K. Stephan leg. Paratype— 1 specimen (FSCA) Arizona: Santa; Rita Mts.; Madera Cyn.; Aug. 31 1968 / gilled fungus; K. Stephan leg. [anterior half of specimen missing, but rest of body corresponds to rest of type series]. Paratype – 1 specimen (FSCA) Arizona: Santa; Rita Mts.; Madera Cyn.; July 28 1968 / gilled fungus; K. Stephan leg. Paratype— 1 specimen (FSCA) Arizona: Pajarito Mts.; Pena Blanca; Sept. 9 1969 / K. Stephan leg.; fungus. Paratype— 1 specimen (FSCA) ARIZONA Pajarito; Mts. Pena Blanca; Cyn. 15 Aug 1970; K. Stephan coll. / Cyllodes ; n. sp. [the last label is handwritten]. Paratype – 1 specimen (FSCA) ARIZONA: Cochise Co.; Chiricahua Mts. jct.; to Methodist Camp; Pinery Cyn., 6000; ft., 16–VIII–1989; P.E. Skelley. Paratype – 13 specimens (CAS), 2 specimens (ARCC): U.S.A.: Arizona; Cochise Co.; Portal / 17 Sept. 1984; L.R. Gillogly / LORIN R. GILLOGLY; COLLECTION; DONATED TO THE; CALIF. ACADEMY OF SCIENCES; MAY 1990 / PARATYPE; Cyllodes ; thomasi ; Det. 2012 Cline and Skelley. Paratype – 5 specimens (UCDC): AZ. Pima Co.; Madera Can.; 23 Aug 75; RB Kimsey / PARATYPE; Cyllodes ; thomasi ; Det. 2012 Cline and Skelley. Paratype – 1 specimen (UCDC): Ramsay Cyn Ariz.; Huachuca Mts.; VIII–13–1947 / L.R. Gillogly; Collector / A.T. McClay; Collector / PARATYPE; Cyllodes ; thomasi ; Det. 2012 Cline and Skelley. Paratype – 1 specimen (UCDC): Madera Cyn.; Santa Cruz; Co. Ariz. 4880; ft. VIII–28–1963 / V.L. Versterby; Collector / PARATYPE; Cyllodes ; thomasi ; Det. 2012 Cline and Skelley. Paratype – 1 specimen (ARCC): ARIZONA: Cochise Co.; Chiricahua Mts., SW Res. Stn.; 31°53’N 109°12’W; 15–22 July 2001; A. Tishechkin, FIT #2 / PARATYPE; Cyllodes ; thomasi ; Det. 2012 Cline and Skelley. Paratype – 2 specimens (LSAM): USA: AZ: Cochise Co.,; Chiricahua Mts., South; Fork, 31°52.066’N; 109°11.333’W, 30VII2010; Park 10–035, J.-S. Park,; ex) under bark / PARATYPE; Cyllodes ; thomasi ; Det. 2012 Cline and Skelley.

Description. Overall, body circular to slightly elliptical and highly convex dorsally. Length 2.8 mm (n = 19; one specimen missing head), width 2.0 mm (n = 20). Body unicolorous dark chestnut brown with abdomen and thoracic ventrites somewhat lighter. Surface sculpturing on dorsum consisting of minute punctures with finely granular to microreticulate interspaces between punctures. Body setation absent on dorsum; entire surface glossy and shining ( Fig. 2 ).

Head moderately transverse (W:L = 1.45:1.00), with shallow depression across anterior part of vertex near frontoclypeal area. Surface punctures small and circular with some crescent shaped, irregular, approximately 1.5 eye facet width in diameter. Punctures more distinctly impressed medially and faintly impressed anteriorly and laterally; appearing evenly distributed across vertex. Interspaces granular to microreticulate, and approximately 1.0–1.5 puncture diameters apart. Antennal grooves present, convergent, and moderately well-defined. Eyes prominent, finely faceted, interfacetal setae absent. Antennal club shape elongate elliptical; club 0.60 length of segments 1–8 combined ( Fig. 4 ). Terminal antennomere shorter than previous two segments combined; apex of terminal segment concave. Scape slightly curved with anterior margin convex; approximately 2 times longer than to pedicel. Pedicel small, barrel-shaped, shorter than segment 3. Clypeolabral junction shallowly concave. Labrum with anterior margin broadly concave with a shallow median indentation. Mandible with multi-dentate cutting apical edge; setigerous furrow with two prominent setae; molar region with large transverse ridges; prostheca with dense setal brush ( Fig. 5 ). Maxillary palpi with terminal segment elongate and somewhat conical, longer than segments 1–2 combined; lacinia with apical margin indentate and setal brush confined to apicomedial region only not extending beyond basal half of structure ( Fig. 6 ). Labial palpi with terminal segment somewhat barrel-shaped and subequal in length to segments 1–2 combined. Mentum moderately transverse with anterior margin possessing a medial point; surface punctuation consisting of faint minute punctures along posterior margin; interspaces smooth to finely microreticulate, surface shining. Submentum with punctures 2 times diameter of those on vertex; surface sculpturing similar to that of mentum.

Pronotum somewhat transverse (L:W = 1.0:2.2), widest near posterior angles, highly convex across disc; punctures circular and similar in size to circular punctures on vertex, surface sculpturing smooth to finely microreticulate and slightly granular along posterior margin. Anterior angles evenly rounded, not projecting. Posterior angles evenly rounded, not projecting. Lateral margins evenly arcuate to posterior angles. Anterior margin with deep trapezoidal notch in medial region for reception of head. Posterior margin almost straight with slight expansion in medial region adjacent to scutellum. Prosternum with space between coxae and anterior margin approximately 2 times width of procoxal process between coxae. Prosternal process slightly expanded posterior to procoxae; a longitudinal carina is present in lateral posterior margin with evenly sloped vertical face. Mesonotum with scutellum obtusely triangular; surface punctation similar to that on pronotum, surface sculpturing granular with some faint microreticulation present. Mesosternum carinate, lower level than metasternum and prosternum; typically obscured by prosternal process. Meso-metasternal junction broadly concave. Metasternum overall transverse (W:L = 1.0:2.5); metasternal disc surface punctation dense with punctures circular and separated by 1–2 puncture diameters, each puncture associated with fine golden seta; surface sculpturing granular. Postcoxal lines of mesocoxae present, diverging from coxal cavities to middle of lateral margin of metasternite; a definitive, large triangular axillary space formed. Elytra completely covering pygidium or with only apex of pygidium exposed; elytral apices separately rounded; lateral margins not explanate; some serially punctate striae visible but other punctures randomly distributed; punctures similar to those on pronotum; sculpturing granular to smooth, shining, glabrous. Humeral angles not developed.

Visible abdominal ventrite 1 projecting between metacoxae with broadly rounded apex ( Fig. 3 ). Metacoxal lines not diverging from metacoxal cavities. Visible abdominal ventrites 2–4 equal in length. Hypopygidium with posterior margin evenly rounded. Pygidium with posterior margin evenly rounded, and bearing short fine golden setae.

Legs unmodified, no sexual dimorphism apparent. Each femora canaliculate for reception of tibiae; widest near middle. Protibiae with crenulate lateral margin and two unequal apical spurs, apical 0.33 of structure more densely setose. Mesotibiae with row of short blunt spines along apical margin; lateral margin, apical margin and distal half of inner margin with thick stiff seta-like spines present. Metatibial armature similar to mesotibiae; inner margin straight with slight apical curvature. Tarsomeres 1–3 lobed with dense empodium ventrally possessing short setae and longer lateral seta; claws simple.

Female genitalia as observed in other Cyllodes species with fused gonocoxites along midline ( Fig. 10 ), and gonocoxites broadly widened at base (L:W = 1.4:1.0).

Male genitalia moderately well sclerotized. Tegmen with two distinct apicolateral tufts of setae, as well as uniformly distributed setae along apical margin ( Fig. 7 ). Tegmen overall short and broad (L:W = 1.45:1.0). Median lobe with apex slightly produced and truncate ( Fig. 8 ). Internal sac sclerites with paired highly sclerotized ejaculatory rods; each end of ejaculatory rod divergent; large fields of callosities present around ejaculatory rods and proximal to ejaculatory rods ( Fig. 9 ).

Diagnosis. Cyllodes thomasi differs from other members of the genus by possessing the following combination of characters: body small, <3 mm in length, mesosternum deeply concave for reception of the prosternal process; terminal antennomere with apical margin concave; maxillary galea with apical margin concave; apex of mandible appearing multi-dentate; mandible with apical setigerous furrow comprising only two elongate setae; male genitalia with tegmen possessing two distinct apicolateral setal tufts.

Variation. Male specimens sometimes, but not always, have the anal sclerite (tergite VIII) partially extruded from the body cavity.

Geographical distribution. The species is known only from the type localities in southern Arizona.

Biology. Label data indicates the species is found under bark or in association with “gilled fungi”. Although this doesn’t necessarily suggest the same host, i.e. Pleurotus ostreatus , as C. biplagiatus , other members of Cyllodes , e.g. the Palearctic C. ater (Herbst) , are also known from Pleurotus ( Audisio 1993) in addition to Agaricaeae and Polyporaceae . Other species of Pleurotus are present in the southwestern United States, and likely this species is associated with one of those taxa and not P. ostreatus . Label data also indicates a summer occurrence of this species from July through September. The appearance of these beetles likely coincides with summer rains in the region and the emergence of host fungi. Summer rains typically represent the most significant precipitation for this area. The specimens found under bark may indicate that the rains had not yet begun, and the beetles were seeking refuge in subcortical spaces.

Etymology. The specific epithet honors our colleague and friend, Dr. Michael Thomas, who has been a major contributor to Cucujoidea taxonomy and systematics.

Discussion/Notes. Cyllodes thomasi apparently does not share a close relationship with C. biplagiatus based on shared adult morphological features. A stronger affinity is shared between this species and Cyllodes camptoides Reitter from Mexico.

Figures

FIGURES 1 – 2. Dorsal habitus images of North American species of Cyllodes. (1) C. biplagiatus LeConte. (2) C. thomasi n. sp. Scale bar = 1 mm.

FIGURES 3 – 6. External characters of C. thomasi n. sp. (3) Ventral habitus; (4) right antenna; (5) right mandible; (6) right maxilla.

FIGURES 7 – 10. Genitalia of C. thomasi n. sp. (7) Male tegmen; (8) Male median lobe; (9) male internal sac sclerites; (10) female ovipositor.