This species can be easily recognised from the congeners by colour patterns on the elytron, with a large arcuate whitish marking open to the lateral margin at base, a small yellow spot on humeral area surrounded by the arcuate marking and a large whitish spot on subapical area (Fig. 1A, B and D). Some other diagnostic characters are: head with a long median suture from vertex to frons (Fig. 1E); antennomeres 1 and 3 laterally flattened in males, scape with inner surface depressed; antennomere 3 concaved anteriorly, with a large laminate process at base (Fig. 1G and H); tergite VIII sub-trapezoid, posterior margin weakly emarginate (Fig. 2B); sternite VIII transverse, nearly divided at middle (Fig. 2C); male genitalia with median lobe sub-cylindrical, inner sac with 1 slender sclerite and 2 small spines (Fig. 2A).

Figure 1.  

Dicranolaius mangalicola Asano＆ Kawashima, 2010. A male, dorsal view; B male, dorsal view; C male, ventral view; D female, dorsal view; E head; F fore tarsi; G male antenna, dorsal view; H male antenna, lateral view. Scale bars: 1.0 mm (A-D).

Figure 2.  

Dicranolaius mangalicola Asano＆ Kawashima, 2010. A male genitalia, ventral view; B pygidium (apical tergite); C ultimate abdominal ventrite (apical sternite).

China: Fujian (new record for China); Japan.

The habitat is mangrove forest (Fig. 3A), this species was collected on the leaves of Aegiceras corniculatum (Fig. 3B）.

Figure 3.  

Habitat and host plant of Dicranolaius mangalicola Asano＆ Kawashima, 2010. A habitat (photo by Haitian Song); B host plant Aegiceras corniculatum (photo by Haitian Song).

This species can be distinguished from the other species of Intybia mainly by the shapes of antennomere 3 (Fig. 4D and E) and male genitalia (Fig. 4G); the depression behind eyes and carina next to it is also rarely known in this genus. The punctations on elytra is also distinguishable, which represented by both coarse and fine punctures mainly on central areas (Fig. 4F).

Figure 4.  

Intybia swatowensis (Wittmer, 1956). A male, dorsal view; B male, ventral view; C female, dorsal view; D male antenna, lateral view; E male antenna, dorsal view; F elytra; G male genitalia, ventral view; H pygidium (apical tergite); I ultimate abdominal ventrite (apical sternite); J anterior tarsi, male. Scale bars: 1.0 mm (A-C).

China: Guangdong, Fujian (new record for Fujian).

Specimens of I. swatowensis are mostly found on leaves or rocks far away from the coast (personal observation by Zhenhua Liu), but was also collected in mangrove forests in this study (Fig. 5A) and were collected on the leaves of Kandelia obovata (Fig. 5B).

Figure 5.  

Habitat and host plant of Intybia swatowensis (Wittmer, 1956). A habitat (photo by Haitian Song); B host plant Kandelia obovata (photo by Haitian Song).

Male. Length 2.9-3.5 mm. Head and prothorax black, with a quadrate orange spot on frons; antenna with basal 3 segments orange, scape with dorsal surface dark, remaining segments brown to dark brown. Elytra black with metallic bluish lustre, with an orange band across suture before middle. Legs black, anterior tarsi of male lacking comb above the 2^nd tarsomere. Abdomen black with median area orange. Vestiture double of dense short setae and much sparser longer bristles.

Head. Head narrower than pronotum; dorsal surface nearly smooth, depressed behind eyes, forming a carina from temple area to ventral side. Eyes elliptical and prominent laterally. Antenna with scape and antennomere 3 expanded and laterally flattened; scape sub-triangular with outer surface slightly depressed; antennomere 3 sub-rectangular, distinctly depressed on outer surface, with a membranous projection near base.

Thorax. Pronotum about 0.9 times as long as wide, lateral margins distinctly constricted at base; disc area smooth, only with a few punctations on lateral areas posteriorly, transversely depressed near base. Prosternum short, prosternal process highly reduced. Procoxal cavities large and transverse, contiguous at middle; procoxae distinctly projecting. Mesoventrite small and shield-shaped, mesepisternum and mesepimeron large. Metaventrite about as long as wide, slightly dilated. Mesocoxae triangular and projecting, meeting at middle. Metacoxae narrowly separated, abruptly narrowed to lateral. Legs relatively slender, with femora slightly enlarged near base, tarsal formula 5-5-5, anterior tarsi without comb on tarsomere 2 (Fig. 4J).

Elytra. Oblong-ovate, widest at about posterior third, about 1.5 times as long as wide; dorsal surface shiny, with sparse coarse punctations mostly on median areas and denser fine punctations between and next to them; vestiture mostly dark, which are yellowish on orange band.

Abdomen. With 6 ventrites, gradually narrowing to posterior; ventrite 1 divided at middle, only visible at lateral. Tergite VIII sub-trapezoid, with posterior margin arcuate; sternites VIII nearly divided, with median area membranous. Male genitalia with penis broadly rounded apically, inner sac with a long sclerotised flagellum and numerous tiny spines apically.

Female. Similar to male on body shape and colouration, but head with dorsal surface entirely black, antenna with scape and antennomere 3 only elongated.