Lioptera erotyloides Bates

Hunting, Wesley & Yang, Man-Miao, 2019, A taxonomic review of the pericaline ground-beetles in Taiwan, with descriptions of new species (Coleoptera, Carabidae, Lebiini), ZooKeys 816, pp. 1-164 : 115-120

Lioptera erotyloides Bates Figs 86A, B, 87, 88 A–D, 89, 94C

Lioptera erotyloides Bates, 1883: 280; Heller 1903: 245; Csiki 1932: 1376; Louwerens 1953: 92; Jedlička 1963: 340; Habu 1967: 97; Lorenz 2005: 458; Park et al. 2006: 102.

Types and other material examined.

Holotype (female) labeled “Type/HT” [circular, ringed with red]; "Japan/ G. Lewis/ 1910-320"; "Yuyama/ 16. V.-14. V.81"; Lioptera erotyloides Bates [handwritten]; NCHU#/100013. [NMNH]. 14 specimens: six males and eight females. For further details see EH Strickland Virtual Entomology Museum Database.

Type locality.

Japan. Yuyama.

Diagnosis.

Specimens of this species are easily distinguished from other Taiwanese pericalines by the large size (more than 11 mm), almost flat elytral intervals, and a mentum with no tooth.

Redescription.

OBL 11.50 - 15.33 mm. Length (n = six males, eight females): head 1.12 - 1.32, pronotum 1.68 - 2.08, elytra 7.75 - 9.83, metepisternum 1.76 - 2.32 mm; width: head 2.60 - 3.20, pronotum 3.28 - 4.20, elytra 5.50 - 7.08, metepisternum 0.96 - 1.32 mm.

Body proportions. HW/HL 2.30 - 2.58; PWM/PL 1.96 - 2.09; EL/EW 1.25 - 1.48; ML/MW 1.70 - 2.11.

Color. Fig. 86A, B. Various. Dorsum of head, clypeus, labrum, pronotum and antennae piceous; palpi piceous, lighter at apex; elytral disc piceous, with four yellow-orange to red maculae, two anterior and two posterior, anterior macula large and rather dentate, from interval 2, to just before outer margin, reaching basal border of elytra in interval 4 to 7, posterior macula more narrow laterally but also and rather dentate, from stria 1, to just before outer margin, closest to base of elytra in stria 4 and 5, closest to apex of elytra in stria 3 and 4; ventral surface piceous; legs rufo-piceous to piceous.

Microsculpture. Head and pronotum with microsculpture slightly transverse to isodiametric; disc of elytra with isodiametric sculpticells; ventral surface with shallow transverse to almost isodiametric microsculpture.

Macrosculpture. Dorsum of head, clypeus and pronotum rugulose, entire surface with scattered setigerous punctures, punctures blending with rugulose surface and setae hardly visible at 50 ×; elytral intervals flat, covered in dense, randomly scattered setigerous punctures, setae hardly visible at 50 ×, striae hardly visible, +/- evenly punctate along length; ventral surface with randomly scattered punctures.

Fixed setae. Two pairs of supraorbital setae; clypeus with two long, lateral setae; labrum with six setae along apical margin; one pair of suborbital setae; pronotum with two pairs of setae, one at base of lateral margin, one on lateral margin at pronotum max width, slightly inset; 29-30 lateral (umbilical) setae in interval 9; elytra with interval 3 with four setae, first in proximity to scutellar setae, second just beyond basal 1/5 of elytra, third 3/5 from base, fourth in proximity to last fixed umbilical seta; ventral surface with two setae on each of abdominal sterna III to VI; four setae along apical margin of sternum VII.

Luster. Dorsal surface moderately dull; ventral surface moderately glossy to glossy.

Head. Mandibles rather robust and long, only slightly curving at apex; labrum quadrate, some specimens with apical margin slightly emarginate; mentum without tooth; eyes large, convex; palpi cylindrical and elongate and setose.

Pronotum. Wide, twice as wide as long; lateral margins explanate, with margins curved upwards; anterior transverse impression moderately deep; posterior transverse impression moderately deep; median longitudinal impression very shallow; posterio-lateral margins obtuse.

Elytra. Hind angles truncate.

Hind wings. Macropterous.

Legs. Tarsal claws denticulate, 5-6 denticles per claw, males with adhesive vestiture ventrally, two rows squamo-setae on tarsomeres 1-3 of fore-leg, two rows of squamo-setae on tarsomeres 1-2 of mid-leg.

Male genitalia. Fig. 88 A–D. Length 2.64 - 2.84 mm. Ostium catopic, rather elongate in ventral view, extended to mid-length of phallus. Phallus cylindrical, widest at mid-length, apex almost triangular in form, rounded at tip; endophallus relatively wide along length, with single, distinctively large basal spine (ebs) and field of moderately large spines (esp) visible on left side in lateral view.

Female genitalia. Fig. 94C. Width 1.68 - 1.92 mm. Gonocoxite 2 (gc2) relatively uniform in width along length, constricting sharply at base of dorsal ensiform setae fovia; two lateral ensiform setae spaced widely apart (les), one dorsal ensiform seta. Sensory furrow, furrow pegs and associated nematiform setae not observed. One spermatheca present (sp1), elongate and cylindrical, expanding slightly in api cal half, distinctive diverticulum (div) at spermatheca base; one spermathecal accessory gland (sg), associated spermathecal gland duct (sgd), with attachment site near apex of divericulum.

Habitat, habits, and seasonal occurrence.

The known elevational range of L. erotyloides is from 250 to 1800 meters with the majority of adults being collected at around 1200 meters. Adults of this species are crepuscular and are found in mixed primary and secondary forest of montane areas. Specimens have been collected from April to December with most specimens collected in May and June. Methods of collecting include m.v. light sheet, malaise trap and hand collecting.

Collecting observations.

In June of 2011, collecting partner and laboratory colleague, Zong Hang Yang with WH collected for an evening at Aowanda National Forest Recreation Area, Nantou county. The site had been closed to the public for some time due to devastation caused by Typhoon Morakot, the previous year. Because of this, there was an abundance of deadwood and fallen trees in the area, being reclaimed by the land for several months. Situations like this can present an excellent opportunity for the collection of pericaline lebiines, due to their association with both the insects and fungi that require and use these microhabitats. That evening WH came across a broken stump that had the north side of it covered in a large patch of frilly, white, bracket fungus; within the folds of this fungus, were numbers of a large adults of large erotylid beetle ( Erotylidae : Megalodacninae) (Fig. 87) together with their larvae, feeding on the fungus. There were dozens of adults and even more larvae. After observing for a time, several individuals of a pericaline lebiine also moving amongst them we observed, L. erotyloides , its name given due to the strikingly similar dorsal coloration it shares with several species of erotylids.

The erotylids and their larvae did not seem to be bothered at all by the presence of the carabids around them. Specimens of the erotylid beetle, the carabids, and also some larvae and associated fungus were collected. Upon researching this type of behavior, a paper by Erwin and Erwin (1976) that detailed the natural history of a New World species of pericaline beetle, Eurycoleus macularis Chevrolat. Apparently, this species is closely associated with a fungus beetle of the genus Amphix ( Endomychidae ), with larvae and adults both relying on them as prey while living amongst them. Erwin considered the natural history of E. macularis as a form of incipient ectoparasitism. He postulated that this behavior could provide proof of an evolutionary intermediate step towards the true ectoparasitism recorded in a few other groups within the Carabidae .

The material was examined and no carabid larvae were present. Over the next three years of fieldwork, this phenomenon was not observed again. It seems possible that L. erotyloides may have a similar natural history as E. macularis but more observations are needed to uncover their true way of life and relationship to their erotylid namesake.

Geographical distribution.

Lioptera erotyloides is known from Korea, Japan, China, Vietnam, and Taiwan. For Taiwan collecting localities see Figure 89.