(Figs. 4–7)

Type material. PHILIPPINES, Bohol, SAVIMA Mangrove. Holotype 1♂, MT 19.730240°N, 123.853148°E; 3 September 2016, (BohSW11 T1 _F32_ R79); Paratype 1♂, MT 49.727948°N, 123.849691°E, 25 June 2016, (BohSW1 T4 _F32_ R62); Paratype 1♀, MT5 9.727738°N, 123.849755°E; 9 June 2016; and (BohSW3 T5 _F32_ R71).

Etymology. The present species is dedicated to Ronald Hazel, an inspiration to the author and who contributed with significant help in the research of Diptera in the Philippines. The species name is a contraction of his name in genitive.

Extended diagnosis. A small species (body 4 mm, wing 3 mm) with brownish antenna; postpedicel nearly as long as high, yellowish brown below. Postocular bristles uniseriate throughout; black above, whitish below and as long as above. Mesonotum with 6 dorsocentrals (dc); anterior 4 dc equally long, posterior 2 dc longer. Upper and lower propleural bristles pale. Legs yellowish brown. Fore coxa brownish, only tip yellowish. Posterior four coxae black. Fore femur dorsally brownish, all tibiae brownish while apical tarsomere of all legs dark brown. Fore coxa with long black bristles nearly as long as coxa is long. Fore femur with a double row of long black bristles. The bristles in the posterior row very long, the longest at base at least 3 times as long as femur is wide, the bristles become gradually shorter toward tip; the bristles in the anterior row half as long as those in the posterior row (Fig. 4). Fore tibia with a double row of fine bristles, those near the middle twice as long as tibia is wide. Tarsomere 1 with long posteroventrals. Mid femur with a double row of ventral bristles. The bristles in the posterior row minute, those in the anterior row, longer; the longest bristles near base nearly as long as femur is wide. Mid femur has a double row of ventral bristles that are nearly as long as femur is wide near the base, gradually becoming shorter toward the tip of the femur. Hind femur with short ventral bristles, hardly half as long as femur is wide. Sternites densely set with black bristles. Wing brownish tinged with black veins. Squama, ciliation and halter white. Male terminalia (Fig. 7). Cerci pale yellowish brown (Fig. 4), dorsally fused (Fig. 7C).

Female (Fig. 6) similar to male but lacking the long bristling on the fore and mid leg.

Remarks. The new species superficially resembles T. longicilia Evenhuis & Grootaert, 2002, known from Singapore, in having long ventral bristles on the fore femur. In Thinophilus ronazeli Ramos & Grootaert sp. nov. the longest ventral bristles on the fore tibia are hardly twice as long as tibia is wide. In T. longicilia the ventral bristles on the fore tibia are at least 3 to 4 times as long as tibia is wide. The ventral bristles on the mid femur in T. longicilia are at least 2 to 2.5 times as long as femur is wide. In the new species the ventral bristles on the mid femur are at most as long as femur is wide.