Two new species of Diptilomiopus Nalepa (Acari: Eriophyoidea) from India

Two new species, Diptilomiopus indogangeticus n. sp., infesting Ficus tinctoria subsp. gibbosa (Blume) Corner (Moraceae), and Diptilomiopus mohanasundarami n. sp., infesting Mangifera indica L. (Anacardiaceae), are described from West Bengal, India. Diptilomiopus holoptelus Chakrabarti and Mondal and Diptilomiopus strebli (Boczek) are possible junior synonyms of Diptilomiopus integrifoliae Mohanasundaram and Diptilomiopus asperis Ghosh and Chakrabarti, respectively.


Material and methods
Eriophyoid mites were collected and mounted as described by Chakrabarti et al. (2017) and Hoyer's medium was used for mounting the specimens. The terminology and classification given by Lindquist (1996) and Amrine et al. (2003), respectively, are followed here. The specimens were examined with a phase contrast microscope Leica DM3000 and photographs  Mohanasundaram, 1986 Spondias pinnata (L.) Kurz, originally listed as its synonym S. mangifera Wild.
Madurai, Alagarmalai, Tamil Nadu, India 2. D. boueae  Bouea macrophylla Griff. Amphor Muang, Prachim Buri Province, Thailand 3. D. cythereae (Chandrapatya, 1991 in Chandrapatya andBoczek 1991) Spondias dulcis Parkinson, originally listed as its synonym S. cytherea Sonnerat Nakon Pathom, Thailand 4. D. integrifoliae Mohanasundaram, 1981 Buchanania latifolia Roxb., originally described from Holoptelea integrifolia Planch (Ulmaceae) Coimbatore, Tamil Nadu, India 5. D. panithus (Boczek, 1989 in Boczek andChandrapatya 1989) Mangifera indica L. Kasetsart University Campus, Bangkok, Thailand were taken with Leica DFC295 camera. All measurements were made following Manson (1996) andde Lillo et al. (2010) and are given in micrometres (µm). Measurements and means are rounded off to the nearest integer and refer to the length of the morphological characters unless specified otherwise. Drawings were made following de Lillo et al. (2010) and Amrine et al. (2003). In the text, measurements of the holotype are followed by the range of measurements of the paratypes plus holotype given in parentheses. Original descriptions and measurements of D. strebli (Boczek, 1992 in Boczek andChandrapatya 1992) and D. holoptelus Chakrabarti and Mondal, 1983 were compared with D. asperis Ghosh and Chakrabarti, 1989 and D. integrifoliae Mohanasundaram, 1981 suspecting their possible synonymies. All type specimens are now deposited in the collection of the Post-Graduate Department of Zoology, Vidyasagar College, Kolkata-700006, India. After publication, holotypes and paratypes will be deposited in public institutions: one slide with paratypes of each species will be deposited in the National Pusa Collection, Indian Agricultural Research Institute, New Delhi; the holotypes and the remnant paratypes will be deposited in the National Zoological Collection, Zoological Survey of India, Kolkata.
Remarks -The name Diptilomiopus ficivorus appeared previously in the Ph.D thesis by Sarkar (2011) for this species.
Male -Not found.
Etymology -The specific epithet is masculine in gender and derived after the name of Prof. M. Mohanasundaram, eminent Acarologist from India.  Differential diagnosis -Diptilomiopus mohanasundarami n. sp. shows most similarities with D. cerberae (Chandrapatya, 1998 in Boczek andChandrapatya 1998) and D. meliae (Boczek, 1998 in Boczek andChandrapatya 1998) in having incomplete orientation of cells on posterior half of prodorsal shield and 6-rayed empodium. But D. mohanasundarami n. sp. can be separated from the above species in having a total of 15 cells on prodorsal shield (20 cells in D. cerberae and 17 cells in D. meliae).
Diptilomiopus mohanasundarami n. sp. remains distinct from D. panithus, another species of Diptilomiopus on Mangifera indica (L.) in having the prodorsal shield with 15 cells; only the coxae I are granulated and the opisthosoma is provided with 58 dorsal annuli and 53 ventral annuli (in D. panithus 16 cells are present on prodorsal shield, both coxae are granulated and the opisthosoma is provided with 43 dorsal annuli and 60 ventral annuli). Apart from this, cellular orientations on the prodorsal shield are totally different. Here, a key is given to separate the Diptilomiopus species on Anacardiaceae.
Remarks -The name Diptilomiopus mangiferae appeared previously in the Ph.D thesis by Sarkar (2011) for D. mohanasundarami for this species.

Diptilomiopus integrifoliae
Comments -Diptilomiopus holoptelus is morphologically identical with D. integrifoliae except for the number of rays on empodium, (the former with 7 rayed and the later with 5 rayed) and described from the same host but its original type specimens could not be studied. This species is probably a junior synonym of D. integrifoliae.
Remarks on the morphological groups within the genus Diptilomiopus -The species of Diptilomiopus are found on several unrelated host plants and a few species (Table 2) have been recorded on more than one host in contrast to most of the other eriophyoids which are host specific (Skoracka et al., 2010). Species currently recorded on different hosts may contain cryptic species. Only morphological study is not sufficient to ascertain their cryptic nature (Li Table 2 List of a few species of Diptilomiopus found on more than one host plant.  , 2014). Application of other tools such as molecular studies, host transfer experiments etc., may "clarify taxonomic uncertainties". However, different subgroups within this genus have not been confirmed yet, but four groups viz. i) having complete network of cells on prodorsal shield or incomplete cell-like ornamentation and ii) another group may be based on the presence or absence of scapular tubercles (apparently there is a tendency of reduction of scapular tubercles in the species of Diptilomiopus) may be presumed. The two species herein described present scapular tubercles but in D. indogangeticus n. sp. complete network of cells are present on prodorsal shield while in D. mohanasundarami n. sp. the cells are incomplete on posterior part of prodorsal shield.