Japanolaccophilus niponensis ( Kamiya, 1939 )

Kim, Joong Youb & Lee, Dae Hyun Lee and Jong Eun, 2024, First record of the genus Japanolaccophilus Satô (Coleoptera: Dytiscidae) in Korea, Journal of Species Research 13 (3), pp. 329-331 : 329-331

Japanolaccophilus niponensis ( Kamiya, 1939)

ḡḏüḡffl (ṉÿ) ( Fig. 1 )

Neptosternus niponensis Kamiya, 1939: 32 Japanolaccophilus niponensis Satô, 1972: 57

Description. Length. 3.0 - 3.2 mm. Body oval, reverse drop-shaped, shiny, strongly convex ( Fig. 1A ).

Color: Head yellow with black band on posterior margin; pronotum yellow with black bands on anterior and posterior margin; elytra dark brown with yellow markings; ventral surface yellow to brown.

Head: semicircular, about two times longer than wide. Clypeus transverse; anterior margin few setae present. Antennae long and slender; antennomere 1 shortest, 2 - 10 slightly apically and longer than wide, 11 long oval. Labrum transverse; anterior margin rounded and antero-medial part emargiante. Maxillary palpomere 1 broad apically, shortest; setae on subapical part; 2 broad apically, with setae on subapical part, 4 longest, 2.0 times as long as 3. Labial palpomere 1 broad apically, shortest; 2 and 3 about 3.0 times as long as 1.

Thorax: Pronotum broad trapezoidal, about 3.0 times as wide as long, widest at posterior corners, lateral margin few setae present; anterior margin round; anterior corner slightly acute; lateral margins rounded; posterior corner rounded; posterior margin transverse V-shaped. Elytron widest at middle, slightly wider than pronotum. Prosternum transverse. Prosternal process long and straight, convex medially; posterior part acuminate, slightly convex, with thin lateral bead, apex acute. Procoxa rounded. Protrochanter subtriangular, with sparse setae on ventral part. Profemur with a row of spines on baso-dorsal part. Protibia with short spines, with a row of setae on dorsal part. Protarsomer 1 about 1.5 times as long as 2; 3 as long as 2; 4 slightly longer than 3; 5 about 1.5 times as long as 4. Protarsal claws shorter than tarsomere 5. Mesocoxa rounded. Mesotrochanter triangular, with sparse setae on ventral part. Mesofemur with a row of short spines on baso-ventral part. Mesotibia with short spines. Mesotibia shorter than femur, with short spines, with a row of setae on dorsal part. Mesotarsomer 1 slightly longer than 2; 3 as long as 2; 4 slightly longer than 3; 5 about 2.0 times as long as 4. Metacoxal apex reversed V-shaped. Metatrochanter triangular. Metafemur as long as tibia. Metatibia with short spines. Metatarsomere 1 longest, 1.2 times as long as 2; 2 as long as 3; 4 slightly shorter than 3; 5 as long as 4. Metatarsal claw slightly shorter than tarsomere 5.

Abdomen: Sternite VI with few setae on medial part. Sternite VII semicircular with sparse setae on median and posterior part. Median lobe of aedeagus long and slender, widest at base, strongly curved at middle ( Fig. 1B ). Paramere asymmetrical ( Fig. 1C, 1D ). Right paramere slightly squamous, with a seta near apex ( Fig. 1D ). Left paramere crescentiform, with a seta apex ( Fig. 1C ).

Material examined. KOREA: 3♂ 6♀, Musa-ri , Miromyeon , Samcheok-si , Gangwon-do, Korea (N37°25 ʹ 5.09 ʺ E129° 07 ʹ 7.05 ʺ; 2 VI 2021; 2♂ 1♀, same data as former except for VIII 2021; 3♂ 3♀, same data as former except for 1 VI 2022.

Habitat. The specimens were collected in Osip Stream. The mainly habitats are found under boulder at the edge of running water and at roots of Salix sp.

Distribution. Korea (new record), Japan.

Figures

Fig. 1. Japanolaccophilus niponensis (Kamiya, 1939) A, habitus (dorsal aspect); B, median lobe (lateral aspect); C, left paramere (dorsal aspect); D, right paramere (dorsal aspect). Scales: 1 mm (A), 0.5 mm (B), 0.1 mm (C, D).