Revision ofCyclocaccusSharp (Coleoptera: Nitidulidae: Nitidulinae)
Hisamatsu, Sadatomo
Bayless, Victoria M.
Carlton, Christopher E.
The Coleopterists Bulletin
2016
2016-12-31
70
4
825
870
DCS
116151
Latreille, 1802
Latreille
1802
[834,1101,1267,1288]
Insecta
Nitidulidae
Animalia
Coleoptera
2
Arthropoda
family
TypeSpecies. Cyclocaccus laeticulusSharp, 1891(designated by Leschen 1999).
Diagnosis.This genus differs from other Neotropical Cyllodiniby the following combination of characters: body round to oval; head without occipital line; frontoclypeal suture incomplete; labrum shallowly emarginate at middle; mandibles with subapical tooth; antennal club usually as long as or slightly shorter than antennal segments I–VIII; antennal segment XI with one or two oval antennal sensillae; scutellum large, apical margin broadly rounded; apical margin of abdominal tergite VII widely rounded or truncate; prosternum narrow, about as wide as greatest width of protibia (except prosternal process); prosternal disc feebly or strongly convex along midline, if disc strongly convex, with tuft of setae at middle in males; meso-metaventrite junction evenly concave; axillary space on metaventrite present, well-developed; metanepisternum about as wide as greatest width of protibia; abdominal sternite III with or without subcoxal lines; apical and lateral margins of tegmen strongly undulating, short and wide, or long and subparallel-sided; gonocoxites deeply incised or square at apex.
Redescription.Length 1.57–2.79 (2.07) mm, width 1.30–2.20 (1.70) mm, depth 0.74–1.30 (0.99) mm ( n= 68). Male.Body round to oval ( Figs. 1, 10, 15); dorsum and venter strongly shining; disc with or without iridescence, strongly convex dorsally, moderately convex ventrally; coloration variable. Head:Hypognathous, wider than long; occipital line absent; frontoclypeal suture ( Figs. 2B, 11B, 16B) incomplete. Clypeus with apical margin almost straight. Labrum ( Figs. 2D, 11D, 16D) shallowly emarginate at middle; disc with a pair of depressions, each possessing 2 long setae. Mandibles ( Figs. 2G, 11G, 16G) strongly curved inwardly; apex acute, with subapical tooth; mola with small grinding surface; prostheca with setal region; dorsal disc with or without latitudinal keel at middle. Maxillae ( Figs. 2F, 11F, 16F) elongate; lacinia prolonged and thick, possessing long and dense setae entirely; palpi with 4 palpomeres; palpomere I shorter than palpomere III; palpomere II longer than palpomere III; palpomere IV conical shape, longer than palpomeres I–III. Labium ( Figs. 2E, 11E, 16E) with 3 palpomeres, palpomere I distinctly shorter than palpomere II; palpomere III slightly longer than palpomere II. Mentum ( Figs. 2E, 11E, 16E) transverse, with anterior margin concave. Eyes large. Genae feebly developed. Antennae with 11 antennomeres; scape elongate, slightly shorter than segments II and III combined; club loosely jointed, as long as or slightly shorter than antennal segments I–VIII; antennal segment XI with 2 ( Figs. 3C, 4E, 5G, 6G, 12C, 13C, 14C, 17C, 18G, 19C, 20C, 21C) or rarely 1 ( Figs. 7C, 8C, 9C) oval antennal sensilla. Antennal grooves ( Figs. 2C, 11C, 16C) shallow, distinctly outlined, moderately converging posteriorly, and widely separated posteriorly. Pronotum:Strongly convex, transverse; lateral margins narrowly explanate; anterior margin evenly, moderately emarginate; anterior angles rounded; posterior angles subrectangular; disc with sparse, minute punctures, or with dense, large punctures, which are slightly smaller than eye facets. Scutellum:Large ( Figs. 2H, 11H, 16H); apical margin broadly rounded; lateral margins sinuate. Elytra:Strongly convex, with subsutural line; lateral margins narrowly explanate; disc with 9 rows of punctures. Abdominal tergite VII with apical margin widely rounded ( Fig. 2I, 11J) or truncate ( Fig. 16I). Venter:Prosternum narrow, about as wide as greatest width of protibia; disc feebly ( Figs. 2A, 11A) or strongly ( Fig. 16A) convex along midline, if the disc strongly convex, with tuft of setae at middle; prosternal process in ventral view moderately expanded behind procoxae, apical margin widely rounded. Mesoventrite strongly carinate at midline. Meso-metaventrite junction evenly concave. Inter-mesocoxal distance ( n= 14) separated by 1.23–2.26 times width of interprocoxal distance. Inter-metacoxal distance ( n= 14) separated by 1.59–2.60 times width of inter-procoxal distance. Metaventrite strongly convex, impunctate; subcoxal bead not broadly connected at middle of metaventrite; metathoracic discrimen absent or present in apical area; axillary space ( Figs. 2A, 11A, 16A) present, well-developed; inter-metacoxal margin widely emarginate. Metendosternite ( Figs. 2K, 11L, 16L) of cucujoid-hylecoetoid type; anterior tendons long and slender, V-shaped; fuscal arms long and slender, straight or slightly arcuately elongated laterally, with a pair of lateral lobe of ventral process at each base, base of furca broadly attached to metaventrite. Metanepisternum ( Figs. 2P, 11Q, 16Q) wide, about as wide as greatest width of protibia; disc impunctate or densely punctate, separated into 2 spaces. Abdominal sternite III with ( Figs. 11I, 16A) or without ( Figs. 2A, 11A) subcoxal lines; subbasal line on each abdominal sternite complete; disc impunctate or punctate; lateral margins of abdominal sternite VII strongly serrate or not. Legs:Femora of normal shape and size; apicolateral corner of protarsi ( Figs. 2L, 11M, 16M) subrectangular; meso- and metatibiae with sublateral line of setae on dorsal face; pro- and mesotarsomeres I–III weakly to strongly bilobed, with dense setal pads; metatarsomeres not bilobed or dilated; pro-, meso-, and metatarsomeres V with 2 pairs of long setae ventrally; tarsal claws simple. Genitalia:Tegmen short and wide or long and slender in ventral view; lateral margins of tegmen strongly undulating ( Figs. 3A, 4A, 4C, 5C, E, 6A, 6C, 6E, 7A, 8A, 9A), not undulating and converging anteriorly ( Figs. 12A, 13A, 14A), or subparallel-sided ( Figs. 17A, 18A, 18C, 18E, 19A, 20A) in ventral view; median lobe long and slender, with long appendages arising from apical 1/3–1/4 of dorsal face, sometimes exceeding apical margin of median lobe. Female.Abdominal sternite VII with apical margin widely rounded; pro- and mesotarsal segments I–III more weakly dilated than those of males. Ovipositor with gonocoxites widely separated at apex ( Figs. 3D, 4F, 5F, 6H, 7D, 8D, 9D) or with squared apices ( Figs. 12D, 13D, 14D, 17D, 18H, 20D, 21D); styli absent. Bionomics.Fungal hosts that have been reported include Cortinariaceae(?), undetermined Agaricales, and undetermined crustose polypores (Leschen 1999). Additional information recorded in data of material examined corroborates associations with fleshy Agaricaleson woody substrates.
Distribution.Neotropical Region ( Mexico, Central and South America).
Comments.We recognize three species-groups and 15 species. Two species included in the C. laeticulusspecies-group ( C. epakrosHisamatsu, new speciesand C. maculatusHisamatsu, new species) occur in the mountains of Mexico. The remaining species occur in Central and/or South America.
KEY TO THE SPECIES- GROUPSOF CYCLOCACCUS 1. Prosternum ( Figs. 2A, 11A) feebly convex along midline, without tuft of setae at middle in males ......................................................... 2 1′. Prosternum ( Fig. 16A) strongly convex along midline, with tuft of setae at middle in males ................. C. morulusspecies-group 2. Disc of metanepisternum ( Fig. 2P) and abdominal sternites not punctate; apices of gonocoxites ( Figs. 3D, 4F, 5H, 6H, 7D, 8D, 9D) incised ...... C. laeticulusspecies-group 2′. Disc of metanepisternum ( Fig. 11Q) and abdominal sternites punctate; apices of gonocoxites ( Figs. 12D, 13D, 14D, 17D, 18H, 20D, 21D) continuous, more or less truncate ........... C. brevicollisspecies-group