Aulonothroscus koreanus, Seung & Han & Lee & Lee & Lee, 2024

Seung, Jinbae, Han, Taeman, Lee, Seunghyun, Lee, Minhyeuk & Lee, Seunghwan, 2024, Taxonomic review of the family Throscidae Laporte, 1840 (Coleoptera: Elateroidea) in Korea, the description of a new species with new generic and species records, Zootaxa 5432 (2), pp. 267-278 : 272-275

Aulonothroscus koreanus sp.nov.

Diagnosis. Frons a paired frontal keel; frontoclypeus broadly bilobed at apical margin; pronotum about 1.6 times as wide as long; length from anterior margin of pronotum to elytral apex about 2.1–2.2 times in male and 2.2–2.3 times in female as long as maximum width; elytral interstriae subflattened, mostly with two rows of punctures at anterior half, and single row posteriorly; prosternal process with marginal carinae laterally, almost reaching anterior margin of prosternum; mesotarsi similar in both sexes; aedeagus about five times longer than wide; phallobase with sinuate lateral margin, deeply emarginate at middle on basal third, about 3.2 times longer than wide; parameres slender, widest at base, slightly narrowed apically, with medial lateral patch of long pubescence; median lobe elongate, weakly biconcaved laterally, about 0.7 times as long as length of parameres.

Description ( Figs. 3–4 ). Male. Body ( Figs. 3A, C–D , 4C) 2.4–2.7 mm long and 1.1–1.2mm wide; elongate-oval, convex; widest at base of pronotum and elytra, length from anterior margin of pronotum to elytral apex about 2.1–2.2 times as long as maximum width; surface coloured red-brown, densely covered with recumbent white-golden setae. Head ( Figs. 3E , 4A) deeply inserted into prothorax, coarsely punctate, becoming denser posteriorly; frons with a pair of frontal keels between compound eyes, slightly divergent posteriorly; anterior margin of frontoclypeus broadly bilobed; compound eyes large, complete, without emargination; antennae ( Fig. 3F ) 11-segmented, with 3-segmented antennal club; scape stout; pedicel almost square, as long as wide; flagellomeres 3–8 subequal, closely attached to each other; flagellomeres 9 and 10 about 1.1 and 1.6 times wider than long, respectively; apical flagellomere securiform, about 2.1 times longer than wide. Pronotum subtrapezoidal, subparallel-sided at basal two-fifths, then abruptly narrowed anterad; about 1.6 times as wide as long; anterior margin weakly arcuate; disc sparsely covered with deep punctures, similar sized as head anteriorly, becoming coarser, larger, and denser laterobasally; sparsely scattered with microscopic punctures between large punctures. Scutellar shield subtriangular, gradually narrowed posterad; as long as wide; covered with fine punctures and setae. Elytra subparallel-sided, gradually narrowed posterad from basal third; about 1.7 times as long as wide; surface punctate as pronotum, larger and coarser apically, wholly intermingled with sparse microscopic punctures between large punctures; elytral stria complete; interstriae subflattened, mostly with two rows of punctures at anterior half, and single row posteriorly. Prosternum subparallel-sided, arcuate at lateral margin, weakly sinuate; anterior margin weakly trilobate; prosternal process ( Fig. 4B ) with marginal carinae laterally, almost reaching anterior margin of prosternum; hypomeron with transverse impression connected with lateral margin of prosternum, forming deep cavity anteriorly and posteriorly; anterior cavity connected with anteriorly open notosternal groove to receive antennae; posterior cavity housing prothoracic leg. Metasternum covered with deep punctures, barely with large punctures medially, becoming coarser, larger, and denser laterally; sparsely scattered with microscopic punctures on whole surface; oblique mesotarsal groove ( Figs. 3C–D ) deep, well-developed, extending from underneath mesocoxa to posterior angle of metasternum. Abdomen with five abdominal ventrites, strongly connated; abdominal ventrite 1 covered with distinctly large punctures, especially at lateral area; ventrites 2–4 punctate more largely and shallowly, becoming coarser, larger, and denser laterally; densely setose; ventrite 5 rounded at apex, laterally smooth. Aedeagus ( Figs. 3J–O ) trilobed, about five times longer than wide; phallobase with sinuate lateral margin, deeply emarginate at middle on basal third, about 3.2 times longer than wide; parameres slender, widest at base, slightly narrowed apically, with medial lateral patch of long pubescence; median lobe elongate, weakly biconcaved laterally, about 0.7 times as long as length of parameres. Legs moderately long, slender; mesotarsi ( Fig. 3H ) about 0.6 times as long as midtibia; tarsomere 1 about 1.8 times as long as 2–3 combined. Female ( Fig. 3B ) mostly similar to male, but can be differentiated by the following characters: body more elongate, length from anterior margin of pronotum to elytral apex about 2.2–2.3 times as long as maximum width; antennal club ( Fig. 3G ) less developed, smaller; flagellomeres 9 and 10 about 1.1 and 1.5 times wider than long, respectively; apical flagellomere about 1.3 times longer than wide; mesotarsi ( Fig. 3I ) similar to those of male; genitalia shown as Figs. 3P–R .

Material examined. (13) HOLOTYPE. Male. Republic of Korea, Deoksu-ri, Danwol-myeon, Yangpyeong-gun , Gyeonggi-do, 06–27.V.2015, Seung et al. leg., by flight intercept trap (SNU) . PARATYPE. Republic of Korea, 2 males and 2 females, Deoksu-ri, Danwol-myeon, Yangpyeong-gun , Gyeonggi-do, Yangpyeong-gun , Gyeonggi-do, 06–27. V.2015, Seung et al. leg., by flight intercept trap (SNU); 3 males, Republic of Korea, Deokgu-ri, Sangdongeup, Yeongwol-gun , Gangwon-do , 04–18. VI.2015, Seung et al. leg., by flight intercept trap (SNU); 1 male and 1 female, Republic of Korea, Osaek-ri, Seomyeon, Yangyang-gun , Gangwon-do , 23. V –05. VI.2018, Seung et al. leg., by flight intercept trap (SNU); 2 males and 1 female, Republic of Korea, Sanga-dong, Andong-si , Gyeongsangbuk-do, 27. V –10. VI.2022, Seung et al. leg., by flight intercept trap (SNU) .

Distribution. Korea.

Remarks. Aulonothroscus koreanus is very similar to A. brevicollis (Bonvouloir) , but can be distinguished by its elytral striation and structures of the aedeagus. Punctures on elytral interval 1 (between elytral stria 1 and sutural stria) of the new species are similarly sized to those of the other intervals ( Figs. 3A–B ), but punctures are distinctly smaller and sparser, separated by 2–5 times their diameter, in A. brevicollis . Additionally, two rows of punctures are present on elytral interval 2 at the anterior half in A. koreanus , while a row of punctures is present in A. brevicollis . Structure of aedeagus are also very similar, but long setae on parameres are present only at middle in A. koreanus ( Figs. 3J–L ), while setae mostly covered nearly the entire lateral surface except the base and apex in A. brevicollis . Aedeagal structure of A. koreanus is also similar to A. longulus , but the latter species has a longer median lobe compared to A. koreanus and its parameres are evenly covered with short setae along the lateral surface, except the base and apex ( Figs. 2J–L ). In most Aulonothroscus species, sexual dimorphism in structure of the mesotarsi are evident (e.g., characteristic structure in A. laticollis , different length ratio of tarsal segments in many species), but the new species has no differences between males and females ( Figs. 3H–I ).

Etymology. The species is named, referring to its occurrence locality, Korea.

Figures

FIGURE 2. Aulonothroscus longulus (Weise, 1879) A, C–F, H, J–O, male; B, G, I, P–R, female A–B, dorsal habitus; C, ventral habitus; D, lateral habitus; E, frons; F–G, antenna; H–I, midleg; J–L, aedeagus (dorsal-ventral-lateral); M–O, male genitalia (dorsal-ventral-lateral); P–R, female genitalia (dorsal-ventral-lateral)(scale bars for A–D: 1mm; E–R: 0.5mm)

FIGURE 3. Aulonothroscus koreanus sp. nov. A, C–F, H, J–O, male; B, G, I, P–R, female A–B, dorsal habitus; C, ventral habitus; D, lateral habitus; E, frons; F–G, antenna; H–I, midleg; J–L, aedeagus (dorsal-ventral-lateral); M–O, male genitalia (dorsal-ventral-lateral); P–R, female genitalia (dorsal-ventral-lateral)(scale bars for A–D: 1mm; E–R: 0.5mm)

FIGURE 4. Aulonothroscus koreanus sp. nov. A–C, male A, lateral view of head & pronotum; B, latero-ventral view of head & prosternum; C, lateral habitus (scale bars for A–B: 0.5mm; C: 1mm)