Triplax nagaoi Nakane, 1977

Park, Boo Hee Jung and Haechul, 2017, First record of two erotylid species of Triplax (Coleoptera: Erotylidae: Tritomini) from Korea, Journal of Species Research 6 (3), pp. 291-294 : 293

Triplax nagaoi Nakane, 1977

[Korean name: Baek-un-san-beo-seos-beol-re] [ Figs. 2 , 4 , 6 ]

Triplax nagaoi Nakane, 1977: 98 .

Description: Body length 3.4-4.3 mm. Body elongateoval, moderately convex, shiny and strongly glabrous; body color mostly reddish-yellow; marking on vertex, a pair of round markings on pronotum, sometimes scutellum elytra and meso- and metasternum black. Head with tiny punctures, with shortly transverse depression behind clypeus; eyes slightly oblique, moderately and roundly produced; ocular distance about three times wider than eyes diameter; antennae not reaching to basal margin of pronotum; third antennomere slender and about twice longer than fourth; 9-11 antennomere strongly enlarged, forming a densely articulated club, apical antennomere circular and narrower than tenth. Pronotum about 2.2 times wider than long, widest at base; convex; with fine punctures; anterior margin weakly emarginate but medi- an part nearly straight, thinly rimmed; lateral sides subparallel-sided, abruptly narrowed anteriorly, moderately rimmed; basal margin weakly arched posteriorly at middle, moderately rimmed. Scutellum tongue shape, with sparse and minute punctures. Elytra strongly convex; with 8 files of distinct striae-puncture; strial punctures deep, distinct and dense; interstriae weakly flat, with tiny and irregular punctures. All tibiae of legs strongly widened apically; 1-4 tarsomeres with dense setae ventrally; fourth tarsomere minute, inserted into third; fifth tarsomere almost equal to four preceding tarsomeres combined together. Male gentalia with median lobe and median slightly stout as in Fig. 4 .

Specimens examined: [JN] 10 exs. Han-jai, Baikun-san (Mt.), donggok-ri, Oklyeong-myeon, Gwangyang-si, 8.ix.2016, B.H. Jung and H.C. Park, from Trametes .

Host fungus: Trametes trogii Berk. , Trametes sp.

Distribution: Korea (New Record), Japan.

Remarks: Triplax nagaoi is rarely observed in Korea and a mycetobiont (an obligatory fungal inhabitant). This species inhabits the fresh fruiting bodies and mycelia of Trametes , which are soft when young and then ligneous when old. Host fungi of this species are ligneous enough for it to feed and breed in it through its life cycle. Both adults and larvae usually feed on and breed in the context of fruiting bodies. In the laboratory, development from first larvae to adulthood took approxmately 40 days.

Figures

Figs. 1-2. Habitus(dorsal). 1. Triplax ainonia; 2. T. nagaoi.

Figs. 3-4. Genitalia (lateral, Each scale bar=0.1 mm). 3. T. ainonia; 4. T. nagaoi.

Figs. 5-6. Antenna (Each scale bar=0.1 mm). 5. T. ainonia; 6. T. nagaoi.