Hidden orange mark fungus beetle (Micrencaustes occulta), Micrencaustes divisa and Micrencaustes navicularis
NEWS - Hidden orange mark fungus beetle (Micrencaustes occulta Yang & Li, sp. nov.) was collected from Yunnan as a new species, specimens of Micrencaustes divisa Arrow 1925 and Micrencaustes navicularis Arrow 1921 collected from Hainan and Guangdong recorded for the first time from China.
Micrencaustes Crotch 1876 (Coleoptera, Cucujoidea, Erotylidae, Erotylinae, Encaustini) includes 44 species known worldwide, 11 species have been reported in China. In recent years, species of the genus Micrencaustes in China have been continuously discovered, mainly distributed in southern China.
M. occulta has a body length: 13.2 mm; width: 6.2 mm, elongate-oval, convex in lateral view, general color black, moderately lustrous. Pronotum with three distinctive teardrop-shaped orange marks. Each elytron with two orange marks, the first mark reaching the basal edge and with a wave at posterior edge; the second mark at basal three fourths, transverse and curved, with a wave at anterior edge.
Head coarsely punctured on vertex. Clypeus finely punctured, anterior edge straight. Clipofrontal sulcus incomplete. Eyes large, coarsely faceted; interocular distance about 0.47 times width of head.
Antennae long, almost extending to posterior edge of pronotum, covered with golden setae; antennome 1 swollen, barrel-shaped; antennomere 2 spherical; antennomere 3 long, slightly swollen at apex, 1.6 times as long as antennomere 4; antennomere 9-11 transverse and compact, forming the antennal club, antennomere 9 expanded apically; antennomeres 10 crescent-shaped, 2.0 times as wide as long; antennomere 11 nearly fan-shaped; relative lengths of antennomeres 2-11: 1.5: 3.6: 2.1: 2.2: 2.3: 2.2: 2.2: 2.8: 2.0: 2.2.
Maxillary terminal palpomere transverse, strongly expanded, nearly triangular, 2.8 times as wide as long. Labial terminal palpomere dolabriform. Mentum small, nearly pentagonal, with middle area triangularly depressed; submentum nearly trapezoidal, with a few coarse punctures in the middle and two extremely coarse punctures at the base.
Pronotum 2.2 times as wide as long, nearly trapezoidal, dorsally convex, with extremely sparse punctures. Anterior edge curved opposite the head; lateral edge curved, with expressed border and slightly narrowing apically; basal edge weakly sinuate, with a few coarse punctures on each side of base.
Anterior angles blunt and slightly protruded, posterior angles almost rectangular. Scutellar shield sparsely punctured, nearly heart-shaped, 1.6 times as wide as long. Each elytron with seven distinct striae, intervals sparsely punctured.
Prosternum finely and sparsely punctured, covered with fine and short setae, anterior edge narrow, posterior edge emarginated. Prosternal process nearly long bell-shaped, prosternal process distinctly and abruptly expanded apically, apical edge of prosternal process emarginated, only slightly extending beyond anterior edge of mesoventrite.
Mesoventrite sparsely punctured, with a triangular depression in middle of posterior edge. Metaventrite finely and sparsely punctured and two elongated transverse depressions at posterior edge. Abdomen sparsely punctured, covered with short setae.
Legs with tibiae gradually widening to apices, tibiae and tarsus covered with golden setae. Male genitalia with median lobe slightly curved, median strut straight, apex slightly wide, 2.3 times as long as median lobe.
The species is named for three indistinct teardrop-shaped orange markings on the pronotum, visible when strong light is shone on the pronotum. The specimen was recorded in Yingjiang, Yunnan Province, China.
M. occulta is similar to M. lunulata (Macleay, 1825) in shape and color. The two species are distinguished by the absence of postmesocoxal stripes, each elytron with seven distinct striae, pronotum with a few coarse punctures on each side of its base, body somewhat shiny (vs. M. lunulata has postmesocoxal stripes, each elytron with eight distinct striae, pronotum with evenly distributed fine punctures, body shiny).
Original research
Yang Y, Zhang X, Liu J, Li J (2024). A new species and two newly-recorded species of the genus Micrencaustes (Coleoptera, Erotylidae) from China. Biodiversity Data Journal 12: e134304, DOI:10.3897/BDJ.12.e134304
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