A NEW SPECIES OF RAMUSELLA HAMMER, 1962 (ACARI, OPPIIDAE), FROM FARS PROVINCE, IRAN

A new species of oribatid mite of the family Oppiidae, Ramusella (Insculptoppia) farsi sp. nov., is described from Fars province, southern Iran. The new species is characterized by the fusiform sensillus, with ten long ciliae on its head; smooth notogastral setae, presence of seta c2, and four pairs of genital setae.


Introduction
Fars province, southern Iran, covers a land area of about 125,000 km 2 (7.6% of total area of Iran) and is located between latitudes 27°-31°N and longitudes 50°-55°E.The elevational range in this province extends from about 450 m in the southern part to 4050 m in the northern part, with a mean of 1491 m a.s.l.The mean annual precipitation ranges from 150 to 1200 mm.Fars is one of the few totally unknown provinces in Iran in relation to the taxonomic study of oribatid mite fauna.In the course of a preliminary faunistic survey of oribatid mites in this province, a number of oppiid mites (family Oppiidae) were collected.Here, we describe one new species belonging to the subgenus of Ramusella (Insculptoppia).

Material and methods
During the course of a faunistic survey of oribatid mites in Fars province over 2009-2010, soil and litter samples were taken from the surface to a soil depth of 10 cm under fruit and forest trees, crop and ornamental plants and weeds.Mites were extracted from soil samples using Berlese-Tullgren funnels fixing in 75% ethanol, cleared in lactophenol and mounted in Hoyer's medium on glass microscopic slides.The slides were placed in an oven at 45 ºC for one week and then the specimens were examined using a light microscope (Zeiss Standard 20).Figures were made by using a drawing tube attached to the microscope.Prodorsum (figs.1-2).Rostrum rounded at tip; rostral setae (ro) long, arched, inserted far to each other on the dorsolateral sides of the rostrum, slightly longer than their mutual distance, with fine ciliae unilaterally; lamellar setae (le) short, about half as long as ro, finely ciliate; interlamellar setae (in) short, as long as lamellar setae, glabrous; exobothridial setae (ex) also short and glabrous, slightly longer than in; sensillus (ss) long, fusiform, its head with ten long barbs unilaterally; bothridia round, with wide opening; three pairs of muscle sigillae situated between the interlamellar setae in two longitudinal rows, two sigillae between each interlamellar seta and bothridium, and some sigillae anterior to each bothridium; lamellar and translamellar lines well developed.

Family
Notogaster (fig.1).Notogaster elongate oval and narrow, rounded in both anterior and posterior directions, dorsosejugal suture convex; nine pairs of notogastral setae long and glabrous, seta c 2 very short, weakly developed, the rest of setae almost equal in length, seta la situated more posterior to lm; Lyrifissure im and latero-opisthosomal gland (gla) opening well developed.
REMARKS.The new species resembles the Turkish species, Ramusella (Insculptoppia) luxtoni (Ayyildiz, 1989) in the shape of the sensillus, by having four pairs of genital setae and approximately equal body length (250-280 µm in Ramusella (I.) luxtoni), but this species differs from the new species by the absence of setae c 2 , shorter sensilli, and same transverse level of setae la (= te) and lm (= ti).In the shape of sensillus, the presence of short, but well developed setae c 2 , and anterior location of setae lm close to la, Ramusella (I.) farsi sp.nov. is also similar to Ramusella (I.) elmela Subías & Rodríguez, 1986(= Oppia sp. Hammer, 1977) from Pakistan, but the latter is distinguishable from the new species by having five pairs of genital setae, and barbulated notogastral, anal and  adanal setae.The Iranian species, Ramusella (I.) iranica, has the notogastral setae c 2 similarly to the new species, but the former species differs in having five pairs of genital setae, barbulated notogastral and adanal setae, far larger body size (390-445 µm in length, 155-180 µm in width), and sensilli only with six barbs.
, situated behind ω 1 , tibia I with extremely long solenidion ϕ 1 and short ϕ 2 , ϕ 2 just under half length of ϕ 1 ; genu I with solenidion σ slightly longer than ω and ϕ 2 ; also tibia IV with solenidion ϕ about same length as dorsolateral setae.