Thinophilus parvulus Samoh, Satasook & Grootaert, 2017

Grootaert, Patrick, 2018, Revision of the genus Thinophilus Wahlberg (Diptera: Dolichopodidae) from Singapore and adjacent regions: A long term study with a prudent reconciliation of a genetic to a classic morphological approach, Raffles Bulletin of Zoology 66, pp. 413-473 : 450

Thinophilus parvulus Samoh, Satasook & Grootaert, 2017

(Fig. 38)

Thinophilus parvulus Samoh, Satasook & Grootaert, 2017: 20 (Figs. 21–24).

Material examined. MALAYSIA, Langkawi , Burau Bay, 1 male, 1 September 2005, (Tio 154, leg. I. Van de Velde), on sandy beach .

Diagnosis. A small species (1.8 mm) remarkable in having the fore tibia bearing a short and a long black posterodorsal bristle in the basal quarter of the tibia. The yellow fore coxa (a little brownish at extreme base) bears only minute white hairs. Fore femur anteroventrally and posteroventrally with very long white bristles in apical half. Fore tibia with some fine brown bristles in basal half that are longer than tibia is wide.

Remarks. Thinophilus parvulus is originally described from Pattani province in the South of Thailand along the South China Sea. The male from Langkawi (Andaman Sea) that reported here, is the second record of the species.

Here I point to a few additional notes to the original description. The fore tibia bears ventrally in the basal quarter a double row of fine brownish bristles that are longer than the tibia is wide. The bristles become shorter in the second basal quarter and minute towards the tip. This character may have been overlooked during the description and it is not visible on the picture in the original description. These long ventral bristles are similar to those of T. minor sp. nov. and T. variabilis Samoh et al., 2017 . Secondly, the hind femur bears a double row of ventral bristles where in the anterior ventral row the bristles point towards the tip of the femur. The bristles in the posterior ventral row are pointing downward and the bristles are longest near the middle of the femur. These characteristics are visible on the picture in the original description but not mentioned as such in the text. Nevertheless, I consider the specimens to be conspecific.

Distribution. Thailand: Pattani (Gulf of Thailand) and Malaysia: Langkawi (Andaman Sea).