| abstract | The present paper describes 5 new species of trombiculid mites of the genus Leptotrombidum, 2 belonging to palpale-group, 2 to akamushi-group pallidum-subgroup, and 1 to a new group, trapezoidum-group. All of the type specimens are deposited in the Fujian Research Institute of Epidemic Diseases.
1. Leptotrombidium (L.) postfoliatum, sp. nov.
Length 297-528µ, width 208-403µ. Galeala branched. Palpal setae formula N-N-B.N.B/7B. Eyes 2×2 on ocular plates. Scutum rectangular, sensilli filiform, no setules on sensillary base. Body setae with two types, the usual setae on the anterior part of body and the narrow willow-leaf-like setae on the posterior part of body. Dorsal setae 28 in number, arranged in 2-8-6-6-4-2. Ventral setae 34-38 in number. Standard measurements: AW 59 PW 66 SB 28 ASB 26 PSB 10 A-P 20 AM 43 AL 29 PL 59 Sens 57.
Holotype larva and 11 paratypes collected off Rattus niviventer confucianus in January, 1976 from Sanming, Fujian.
2. Leptotrombidium (L.) allosetum, sp. nov. Length 380-587µ, width 244-479µ. Galeala branched. Palpal setae formula N-N-B.N.B/7B. Eyes 2×2 on ocular plates. Scutum rectangular, sensilli filiform, no setules on sensillary base. Body setae with two types, the usual setae on the anterior part of body and the coarse-ciliated setae on the posterior part of body. Dorsal setae 28-32 in number, arranged in 2-8-6-6-4-2 or 2-8-6-6-4-4-2. Ventral setae 33-39 in number. Standard measurements: AW 62 PW 71 SB 30 ASB 29 PSB 13 A-P 18 AM 42 AL 36 PL 53 Sens 51.
Holotype larva and 7 paratypes collected off Apodemus agrarius in September, 1975 from Pucheng, Fujian.
The palpal setae formula, the pattern and number of dorsal setae and the situation of setae on coxae III of L. postfoliatum and L. allosetum are completely different from those of the species with two types of dorsal setae described in recent years, such as L. peniculatum Traub et Lakshana, 1966 and L. malayanum Nadchatram et Upham,1966.
3. Leptotrombidium (L.) dongluoensis, sp. nov.
Length 221-515µ, width 171-426µ. Galeala branched. Palpal setae formula N-N-B.N.N/7B. Eyes 2×2 on ocular plates. Scutum rectangular, sensilli filiform, with distinct setules on sensillary base. PLs/SB. Dorsal setae 28-32 in number, arranged in 2-8-6-6-4-4-2. Ventral setae 40-46 in number. Setae on coxae III situated beneaththe frontal margin. Standard measurements: AW 58 PW 62 SB 27 ASB 25 PSB 13A-P 21 AM 35 AL 30 PL 50 Sens 43.
Holotype larva collected off Rattus losea exiguus in April, 1962 from Changle, Fujian.
L. dongluoensis, sp. nov. is very similar to L. yui (Chen et Hsu, 1955), from which it is distinguished chiefly by the number and arrangement of dorsal setae, and the length of A-P.
4. Leptotrombidium (L.) discum, sp. nov.
Length 396-594µ, width 267-505µ. Galeala branched. Palpal setae formula N-N-B.N.N/7B. Eyes 2×2 on ocular plates. Scutum rectangular, with posterior margin strongly convex, but nearly straight near the center, like a sideview of a round dish. Sensilli filiform, with distinct setules on 1/3 of sensillary base, and long barbs on distal 2/3. Dorsal setae 32-34 in number, arranged in 2-8-6-6-4-4-2. Ventral setae 50-54 in number. Setae on coxae III situated beneath the frontal margin. Standard measurements: AW 54 PW 57 SB 24 ASB 27 PSB 13 A-P 20 AM 45 AL 34 PL 56 Sens54.
Holotype larva and 9 paratypes collected off Rattus niviventer confucianus in November, 1977 from Shaowu, Fujian.
L. discum, sp. nov. is very similar to L. lanceolatum (Lawrence, 1952), but the latter has larger PW and SB, and different arrangement of dorsal setae.
5. Leptotrombidium (L.) trapezoidum, sp. nov. Length 442-482µ, width 353-406µ. Galeala branched. Palpal setae formula N-N-B. N.B/7B. Eyes absent. Scutum somewhat trapezoidal, posterior margin slightly convex and concave inward in the middle part. PW:A-P=3:1. SB on the PLs line. Sensilli filiform, no setules on sensillary base. Dorsal setae 24-26 in number, arranged in 2-8-6-2-4-4 or 2-8-6-2-4-2. Ventral setae 24 in number. Setae on coxae III situated beneath the frontal margin. Standard measurements: AW 50 Pw 72 SB 24 ASB 23 PSB 10 A-P 21 AM 36 AL 27 PL 48 Sens 47.
Holotype larva and 3 paratypes collected off Rattus bowersii latouchei in November, 1977 from Shaowu, Fujian.
L. trapezoidum, sp.nov. is similar to L. fulleri (Ewing, 1945) and L. bhimtalensis (Womersley, 1952), but the former lacks of eyes and ocular plates and also differs in the data of standard measurements.
L. trapezoidum, sp.nov. is placed in a new species-group, the trapezoidum-group of the subgenus Leptotrombidium. A key to the species-groups of the subgenus Leptotrombidium is given. |