Platyintybia zhongshanensis Liu & Wang sp. nov.

The genus name is a combination of the Latin word platys and the genus name Intybia; platys means broad, referring to the modified terminal antennomere in male. Gender feminine.

This genus can be recognized from other genera of Apalochrini by combination of the following male specific characters: antenna with scape and antennomere 3 dilated and modified, antennomere 11 enlarged and flattened; head with pair of concavities on head between eyes; front tarsi 4-segmented, without comb on tarsomere 2. It can also be separated from Collops Erichson, 1840 and some species of Notointybia Liu, Ślipiński & Pang, 2020, which also with 4-segmented front tarsi, by having lateral margins of the pronotum without a bead.

Length about 2.7mm.

Male. Head and pronotum black, elytra black with pair of large white spots at about basal fourth and pair of smaller white spots at about anterior fourth; antenna yellow with base of scape and terminal segment black; ventral surface mostly black, abdomen orange with lateral areas more or less black. Vestiture comprising double row of dense, short, whitish setae and sparser, longer, black bristles.

Head subtriangular, widest across eyes; vertex with pair of large concavities besides eyes; frons flattened dorsally, moderately constricted in front of eyes. Dorsal surface covered with dense, short, depressed whitish setae, sparser between antennal insertions and absent on concavities. Eyes relatively large, distinctly protruding laterally, finely facetted. Antenna 11-segmented, laterodorsally inserted on frons; scape and antennomere 3 dilated and modified; antennomere 11 flattened and expanded. Maxillary palps with terminal palpomere dilated, cupped, and apical surface depressed; labial palps with terminal palpomere conical.

Pronotum longer than wide, widest at about middle; lateral margins slightly curved, moderately constricted at base, without lateral carina; posterior margin nearly truncate. Disc finely, densely punctate, smoother at middle, posterior area with shallow transverse depression, covered with dense, depressed setae. Prosternum short, with deep incision anteriorly between pronotum and prosternum. Procoxal cavities transverse, continuous at middle, externally open. Procoxae projecting, with protrochantins exposed. Scutellum with visible part subtrapezoidal, posterior margin almost truncate.

Elytra with dorsal surfaces finely and densely punctate, covered with dense, depressed, whitish setae and longer, sparse, black setae posteriorly; epipleura incomplete, extending to abdomen. Meso- and metaventrite without distinct punctuation, covered with dense depressed setae; metaventrite moderately dilated, with short discrimen; metepisternum broad at base, not extending to posterior margin of metaventrite ventrally. Mesocoxae subtriangular, projecting, with exposed trochantins. Metacoxae subtriangular, sharply narrowed laterally. Legs with femora slightly dilated at about basal third; tibiae slender, covered with dense, short setae along inner edge; hind tibiae slightly curved; tarsal formula 4-5-5, with basal tarsomeres slightly prolonged ventrally.

Abdomen with 6-segmented ventrites, freely articulated, gradually narrowed to posterior. Tergite VIII transverse, subtrapezoidal, with pair of anterior struts; sternite VIII nearly divided, weakly connected by membrane at middle (Fig. 4). Aedeagus slender and curved, with apex upwardly curved; endophallus with 1 slender sclerite and a few short sclerites around it.

Female. Similar to male in body shape and colouration, but antenna with basal and apical segments simple, head without concavity on vertex, and front tarsi 5-segmented.

China (Fujian, Guangdong); Malaysia (Borneo).

The species name is derived from Zhongshan, a city of Guangdong Province in South China, where Kongxia, the type locality of the new species, is located.

Holotype : China–Guangdong Prov. • ♂: Zhongshan, Kongxia Village; 22.39510°N, 113.46785°E; 30 May 2023; net sweeping on grasses near stream; Zhenhua Liu leg.; IZGAS COL0001.

The new species resembles Platyintybia sarawakensis in the shape of the basal antennomeres and aedeagus, but it can be easily recognized from the latter by the transverse basal spot and a much smaller subapical spot on the elytra (Fig. 1A). It also differs from P. sarawakensis in the following characters in males: apical antennomere more rounded (Fig. 3C); front tibiae distinctly slender (Fig. 3D); tergite VIII with posterior margin less emarginate (Fig. 4C); penis less curved laterally (Fig. 4A, F), apex of penis more depressed ventrally (Fig. 4B, G), the shape of long sclerite in inner sac (Fig. 4B, G).

Figure 1. 

Habitus of Platyintybia zhongshanensis Liu & Wang, sp. nov. A dorsal view, male B ventral view, male C lateral view, male D habitus photograph. Scale bars: 1 mm for A–C.

Length 2.7 mm.

Male. Antenna mostly yellow, with base and inner edge of scape and apical antennomere black. Legs with middle and hind legs black; front leg with basal half of femora and base of tibiae black, apex of tibiae and apical tarsomere dark brown, remaining parts yellow. Elytra with basal spots whitish and transverse, not extending to lateral or inner suture; subapical spots much smaller, more or less yellowish. Abdominal ventrites mostly orange-red, with lateral areas black.

Head about 1.1 times as wide as pronotum; concavities on head almost extending to anterior margin of eyes; width of vertex between concavities about 1.1 times as wide as concavity across middle of eyes. Dorsal surface of head with pair of circinately arranged setae behind antennal insertions and one on vertex between concavities. Antenna with scape elongate, subtriangular, and constricted at base; antennomere 3 elongate, with a large lamellate process at base, dorsal surface with 1 large, rounded anterior concavity and 2 much smaller basal concavities.

Pronotum about as long as wide. Elytra about 1.6 times as long as wide; epipleura extending to apical margin of elytra but not to apex. Front tibiae about 7.7 times as long as wide, front tarsi 4-segmented.

Abdomen with tergite VIII subtrapezoidal, posterior margin with wide, transverse emargination (Fig. 4C); sternite VIII divided. Male genitalia with penis slender, dorsoventrally curved, apex constricted and upwardly curved; inner sac with a slender and curved sclerite and a few small sclerites around it, apex with dense small denticles (Fig. 4A, B).

Female. Unknown.

China (Guangdong).

This species is collected with Intybia swatowensis (Wittmer, 1956) on grass beside a stream in a village, which is consistent with the habitat of most Apalochrini. Feeding habits and behaviour of this species are unknown.

As for Platyintybia zhongshanensis (Fig. 3F–I).

Holotype : Malaysia • ♂: Borneo, Mount Mattang, W. Sarawak, 1000 m elev.; 17 Jan. 1914; G.E. Bryant leg.; BMNH.

China – Fujian Province • ♂: Zhangzhou, Zhangjiangkou mangrove forest; 23°55′21.75″N, 117°24′54.96″E; 17 Oct. 2022; Malaise trap; Rongxiang Su leg.; IZGAS COL0002. • ♀: Zhangzhou, Zhangjiangkou mangrove forest; 23°55′21.75″N, 117°24′54.96″E; 17 Oct. 2022; beating on Avicennia marina (Forsk.) Vierh.; IZGAS COL0003. • 1 ♂, 1 ♀: Zhangzhou, Zhangjiangkou mangrove forest; 23°55′21.75″N, 117°24′54.96″E; 5 m a.s.l.; 29 Aug. 2023; YF Zhang leg.; FAF COL0001 to 0002. • 2 ♀: Zhangzhou, Zhangjiangkou mangrove forest; 23°55′21.75″N, 117°24′54.96″E; 5 m a.s.l.; 16 Sep. 2023; YF Zhang leg.; FAF COL0003 to 0004. • 2 ♂, 5 ♀: Zhangzhou, Zhangjiangkou mangrove forest; 23°55′21.75″N, 117°24′54.96″E; 5 m a.s.l.; 16 Sep. 2023; YF Zhang leg.; FAF COL0005 to 0011.

Figure 2. 

Platyintybia sarawakensis (Champion, 1921) A dorsal view, male B ventral view, male C dorsal view, female D holotype, male E label information. Scale bars: 1 mm (A–C).

Length about 2.7 mm.

Male. Antenna mostly yellow with base of scape and apical antennomere black. Legs with femora mostly black, apex of front and middle tibiae rufous; front tibiae and tarsi rufous, middle tibiae brownish to black, hind tibiae black with basal part rufous, middle and hind tibiae brownish. Elytra with basal spots large and suboval, not extending to lateral or inner suture; subapical spots rounded, a little smaller. Abdominal ventrites mostly orange-red, with lateral areas black.

Figure 3. 

A–E Platyintybia zhongshanensis Liu et Wang, sp. nov. F–J Platyintybia sarawakensis (Champion, 1921) A, G antenna, male B, H lateral view of basal antennomeres, male C, I dorsal view of antennomere 11, male D, F fore tibia, male E, J dorsal view of head, male.

Head about 1.1 times as wide as pronotum; concavities on head not extending to anterior margin of eyes; width of vertex between concavities about 1.5 times as wide as concavity across middle of eyes. Dorsal surface of head with pair of circinately arranged setae behind antennal insertions. Antenna with scape elongate, subtriangular, and constricted at base; antennomere 3 elongate, with large lamellate process at base, dorsal surface with 1 large, transversely elliptical anterior concavity and 2 indistinct basal concavities.

Pronotum about as long as wide. Elytra about 1.5 times as long as wide; epipleura not extending to apical margin of elytra. Front tibiae about 6.4 times as long as wide, front tarsi 4-segmented.

Abdomen with tergite VIII subtrapezoidal, posterior margin with shallow emargination (Fig. 4E); sternite VIII divided. Male genitalia with penis slender, dorsoventrally curved, apex constricted and upwardly curved; inner sac with a slender, curved sclerite and a few small sclerites around it, apex with dense, small denticles (Figs 4F, 4G).

Figure 4. 

A–C Platyintybia zhongshanensis Liu & Wang, sp. nov. E–G Platyintybia sarawakensis (Champion, 1921) A, F male genitalia, dorsal view B, G male genitalia, lateral view C, E tergite VIII, dorsal view D sternite VIII, ventral view.

Female. Resembling male in colour and body shape, but with antennae more brownish, scape and antennomere 3 only slightly dilated, terminal antennomere simple; head without concavity on vertex; front tarsi 5-segmented.

China (Fujian), Malaysia (Borneo).

Information on feeding habits and behaviour is scarcely known. The Chinese specimens were found on the leaves of plants in a mangrove forest, and the holotype was collected on Mount Matang without details of the habitat noted.