Monographis tamdaoensis new species

Figures 13–17

Material examined: Holotype, adult male (IEBR-Myr 989) and paratypes: Adult, two males (IEBR-Myr 990) two females (IEBR-Myr 991) and, two subadults with 12 pairs of legs (IEBR-Myr 992) were collected from Tam Dao National Park, 21.458611N, 105.649444E, elevation 1017 m, Vinh Phuc Province, northern Vietnam. All types were deposited in the Institute of Ecology and Biological Resources, Vietnam. Specimens were collected by author CH in the field trip organised by Dr Duc Anh Nguyen, on 17 th July 2017.

Diagnosis: Body length 2.4–3.2 mm. Antennal article VI with 16–18 bacilliform sensilla forming crescent shape, setiform sensillum located in anterior position, conical sensillum present near centre of crescent. Labrum asetose, long slender anterior setae in anterior margin. Telotarsus with posterior lateral process shorter than half-length of claw, anterior lateral and lamella processes present, anterior setiform process shorter than half-length of claw.

Description:

Holotype male body 2.4 mm; paratypes: males 2.2–2.4 mm, females 3.0– 3.2 mm; caudal bundle 0.5 mm, nest trichomes 0.2 mm.

Head: Arrangement of post vertex trichomes as for Monographis cattienensis with the holotype having 13 sockets (L) and 14 (R) in anterior rows, posterior rows with 3 sockets on both sides (Figures 13A & 13B). Paratype showed anterior rows with 12–14 sockets, posterior rows with 2–3 sockets (Figure 16A). Clypeo-labrum: Holotype, labrum posterior margin with 8 setae (Se), these setae longer in length than labrum width (paratype with 8–10 setae). Labrum surface asetose (l), labrum posterior margin has a row of minute backward-pointing setae (sb). Lateral lamella (Ll) and single broad lamella each side median cleft (mc), 12–14 slender setae (sa) present on anterior margin of labrum (Figures 13C & 16D) .

Antennae: Antennal article VI with 16–18 bacilliform sensilla. Holotype with 16 bacilliform sensilla forming a crescent shape with 3 thick (T), 9 thin bacilliform sensilla (t) and 4 medium-length thin bacilliform sensilla (tm), setiform sensillum (S) located in anterior position, conical sensillum (C) present near centre of crescent (Figures 14C, 17B &17C).

Telotarsus: Claw slender, posterior lateral process (p) shorter than half-length of claw, anterior lateral (a) and lamella processes (la) present, anterior setiform process (s) less than half-length of claw (c). (Figures 15B & 17D).

Telson: Arrangement of dorsal ornamental trichome sockets similar to M. cattienensis with 17 sockets of trichomes a left side and 18 sockets on right side of the telson in the holotype (paratype with 16–18 sockets). (Figure 15C).

Remarks: Monographis tamdaoensis sp. n. is distinguished from congeners in its labrum structures and anterior setiform process equal to half-length of claw.

Etymology: Monographis tamdaoensis is named after Tam Dao National Park in Vinh Phuc Province, Vietnam.