Lankaphthona phuketensis (Gruev, 1989), status restored

Ruan, Yongying, Konstantinov, Alexander S., Prathapan, Kaniyarikkal D., Zhang, Mengna & Yang, Xingke, 2019, A review of the genus Lankaphthona Medvedev, 2001, with comments on the modified phallobase and the unique abdominal appendage of L. binotata (Baly) (Coleoptera, Chrysomelidae, Galerucinae, Alticini), ZooKeys 857, pp. 29-58 : 29

5. Lankaphthona phuketensis (Gruev, 1989), status restored comb. nov. Fig. 6

Longitarsus phuketensis Gruev, 1989: 97. Type locality: Thailand, Phuket Island. Type depository: Gruev Collection, Bulgaria.

Philotarsa laosica Medvedev, 2009:147. Type locality: Laos, Lhammomuang Prov., Ban Khoungham (Nanin). Type depository: L. Medvedev Collection, Russia. New Synonym.

Lankaphthona binotata : Medvedev, 2009: 202 (misidentification)

Distribution.

Laos, Thailand.

Description.

Body pale yellow to yellow brown. Each elytron with three brown to black markings: elongate one in middle, a longitudinal one on sutural margin and a round one near elytral humeral calli. Legs fulvous, metafemur dorsally brown to black. Body oval, slightly elongate in dorsal view; dorsum convex in lateral view. Body length: 2.2-2.4 mm. Body length to width ratio: 1.88. Pronotum width to length ratio: 1.66. Pronotum width at base to width at apex ratio: 1.22. Elytron length (measured along suture) to width of both ratio: 1.43. Length of elytron to length of pronotum ratio: 3.53. Width of elytra at base (measured in middle of humeral calli) to width of pronotum at base ratio: 1.27.

Vertex impunctate, except few shallow punctures near eyes. Antennal calli obliquely elongate, sub-triangular, conjoined, entering interantennal space. Supracallinal, supraantennal, suprafrontal and supraorbital sulci well developed. Frontal ridge proximally acute, in lateral view moderately convex, produced between antennal calli. Antennal socket close to eye. Eyes strongly enlarged. Frontal and anterofrontal ridges merge gradually.

Antennae filiform, long, about 0.7-0.8 times body length. Antennomere 2 robust, as long as antennomere 3, slightly shorter than 4, following antennomeres elongate. Length to width of antennomere 9 ratio: 4.11 (measured in female). Length to width of antennomere 10 ratio: 3.77 (measured in female). Length to width of antennomere 11 ratio: 3.81 (measured in female).

Pronotum rectangular, slightly convex; base with distinct, slightly sinuate antebasal impression; punctures sparse, shallow and minute. Diameter of pronotal punctures 3-4 times smaller than distance between adjacent ones. Pronotal punctures smaller than elytral ones. Anterolateral callosity of pronotum obliquely truncate. Basal margin slightly convex in middle.

Elytral humeral callus moderately developed. Elytron without impressions or ridges. Elytral punctures small, irregularly arranged.

Length to width of metatibia in dorsal view ratio: 5.17. Width of metatibia at base to width at apex in dorsal view ratio: 0.39. Length of metatibia to length of first metatarsomere ratio: 1.98.

In ventral view, aedeagus sinuate at sides, dilated before apex, abruptly narrowed near apex, with acute apical denticle. In lateral view, aedeagus straight from base to subapex, with apex bent ventrad.

Type material.

Holotype of Philotarsa laosica Medvedev, 2009: ♀ (LMCM), labels: 1) Laos, Khammouang Prov., Ban Khounkham (Nahin), 18°13'N, 104°31'E, 200 m, 9.vi.2005, leg. O. Gorbunov.

The type material of Longitarsus phuketensis Gruev, 1989 is unavailable to this study. Species concept is based on the author’s (Gruev, 1989) descriptions and illustrations on habitus and aedeagus of holotype.

Remarks.

Medvedev (2009: 202) synonymized Longitarsus phuketensis Gruev with Lankaphthona binotata (Baly). However, as we mentioned above, in the same work Medvedev (2009) erroneously identified a species that he described as Philotarsa laosica as L. binotata . Based on the original description and illustration of the habitus and aedeagus of the type provided by Gruev (1989), it is evident that Longitarsus phuketensis is clearly different from Lankaphthona binotata and can be separated by the following characters: apical and basal spots present on elytron (apical and basal spots on elytron are absent in Lankaphthona binotata ); aedeagus straight from base to subapex in lateral view, with acute apical denticle in ventral view (in Lankaphthona binotata , aedeagus curved ventrally from base to near apex, without acute apical denticle); body length slightly larger (2.40 mm in Longitarsus phuketensis , 1.90-2.20 mm in Lankaphthona binotata ).

Based on Medvedev’s suggestion of the synonymy of Longitarsus phuketensis and Philotarsa laosica (erroneously identified as L. binotata ) and our observations of the holotype of Philotarsa laosica , we here synonymize Philotarsa laosica Medvedev, 2009 with Longitarsus phuketensis Gruev, 1989.

Lankaphthona phuketensis is close to L. notatipennis in the similar pattern of maculation on elytron (e.g., having apical and basal spots), the type localities of the two species are also very close to each other. But L. phuketensis can be differentiated from L. notatipennis by the aedeagus straight from base to near apex in lateral view, with acute apical denticle in ventral view (in L. notatipennis , aedeagus curved ventrally from base to near apex, without acute apical denticle in ventral view).