THREE NEW SPECIES OF THE GENUS PROTOGAMASELLUS KARG , 1962 ( ACARINA : MESOSTIGMATA : ASCIDAE ) FROM INDIA

Karg (1962) established the genus Protogamasellus to include Protogamasellus primitivus as type-species from Gernamy. Lindquist and Evans (1965) gave a detailed generic concept and included Rhodacaropsis massula Athias-Henriot, 1961 under the genus Protogamasellus. They also considered the possibility of inclusion of some other Athias-Henriot's (1961) species viz., Rhodacarellus mica, Rhodacaropsis anguistiventris and R. cognatus. Later, Genis et al. (1967) described some new species and subspecies from the Ethiopian region. They also confumed the nomenclatural status of Rhodacarellus mica as Protogamasellus mica. Through the works of various acarologists (Shcherbak, 1976; Shcherbak and Petro va, 1987; Karg, 1977 and Evans, 1982 etc.) around 19 species and subspecies of Protogamasellus are known all over the world.

,um in length respectively.Peritreme visible dorsally reaching posterior to setae s I (Fig. I).
Tritosternum bipartite, serration of lacinae restricted to distal half only.Sternal shield (64.62pm long along midline, 31.72,umwide between coxae II and III) with three pairs of sternal setae, stl being largest (Fig. 2); anteromedian margin of sternal shield slightly convex in nature and not clearly distinguishable; posterior margin strongly concave; fourth sternal setae placed on ventral membrane just below posterolateral comer of sternal shield.Genital shiel~ with paired genital setae, anterior margin rounded, posterior margin truncate.Ventri-anal shield (I03.4,umlong, 37.69pm wide) with five pairs of setae excluding a pair of para-anal and a post-anal setae; V-shaped incision present on anterior margin immediately below base of setae Jv I; large prominent anal shield flanked by two para-anal setae; ventral membrane with three pairs of setae around ventrianal shield, large stigmatal opening placed beside coxae IV; peritreme extending upto posterior level of coxa II.
Remarks: Protogamasellus primitivus machadoi described by Genis et al. (1967) from Angola, Ethiopia shows some affinities with new species Prologamasellus indica in the following aspect : length and nature of dorsal setae, shape of tritosternum, number and nature of setae on ventrianal shield and dentition of chelicerae.However, P. indica can be easily distinguished in having 16 pairs of setae on anterior dorsal shield, length of sternal setae stl-st3 (which is subequal in Protogamasellus primitivus machadoi), oval-shaped metapodal shield, shape of tectum and shape of genital shield.
Tritosternum long with paired lacinae, more than half 'of the distal len~h of lacinae serr~ted (Fig. 6).Sternal shield (141,um long, 96.35,um wide) with 3 pairs of sub equal sternal setae; posterior margin of sternal shield highly concave, anterior region of sternal shield reduced ~o granular sclerotised area with a median groove; setae st 1 arises from granular sclerotized area, first sternal pore situated on anterolateral margin of sternal shield.Metasternal setae borne on interscutal membrane.Genital shield boldly punctate, with paired genital setae; conspicuous dotted area behind genital shield notable; ventri-anal shield (136.9,umlong, 79.9,um wide) fused po'steriorly with body margin, lightly punctate over 3/4 of posterior region; two pairs of simple setae excluding a pair of para-anal and a post-anal setae present on ventri-anal shield; anal aperture moderately sized; para-anal setae placed wide apart; ventral membrane around ventri-anal shield bears 7 pairs of simple setae; para-anal setae and setae Jv5 subequal in length (47,um).Metapodal shield oval in shape along with its component present lateral to the anterior margin of ventri-anal shield.Peritreme extending halfway along breadth of coxae II.
Tectum with a median spine, evenly denticulate along its margin (Fig. 7).Movable chela bidentate; fixed ch.ela with a set of teeth of irregular shape and size on its masticatory surface (fig.8).PaJp apoteJe two-tined, corniculi tapering.gradually to rounded tip.Seven rows of hypognathal denticles present ventrally on gnathosoma.
Male : Anterior and posterior dorsal shield with 17 and 15 pairs of simple setae respectively (Fig. 11); some setae on both shields relatively longer in length than in female; unlike female, lateral membrane with 10 pairs of setae.Posterior region of opisthonotal shield behind z6 and region of •podonotal shield anterior to Z 1 and J 1 lightly sclerotized, peritreme visible dorsally; anterolateral remnants of peritrematal shields present.
Tritosternum same as in female (Fig. 12).Sterniti-genital shield (14S.7,umlong, 98.77,um wide at level between' coxae II and III) with 4 pairs of setae; more or less lightly sclerotized over the entire surface; first sternal setae arises from heavily sclerotized presternal area; stII-stIV subequaJ in length; posterior region of sterniti-genital shield lightly sclerotized; posterior region of shield with a transverse "slit-like' marking; genital orifice large, prominent, presternal in position, overlapping median groove.Ventri-anal shield (136.3,umlong and 89.3,Um wide) fused with body margin, with six paired and one unpaired setae.Anal aperture comparatively larger than that of female; para-anal setae lie closer to anterior margin of anal shield; paired minute setae on ventral membrane lie in close proximity with ventri-anal shield.Peritreme extending upto mid-level of coxa Iv.
Tectum basically same as in female with a minor variation on one ridge (Fig. 13).Movable chela tridentate having one large and two small teeth, fixed chela with a set of six teeth, spermadactyl small (Fig. 14); pedipalp same as in female; no difference in gnathosoma between two sexes discernible.
Remarks : The new species Protogamasellus keralaensis shows affinities with its allied species P. dioscorus Manson, 1972,' intercepted at Auckland, New Zealand from yam in re.spect of natpre of setae on dorsum, elongated opisthonotal and ventri-anal shield, similar shape of tectum, sternal shield and ventri-anal shield, but on closer examination it reveals a number of dissimilarities such as number of setae on anterior dorsal shield, length of setae j 1, J Sand exceptionally long setae ZS, shape of tritosternum, components of metapodal shield, number of setae on ventri-anal shield and ventral membrane and presence of spine-like setae on leg IV.Male of P. keralaensis also shows differences with male of P. dioscorus in respect of shape of ventrianal shield, shape of tritosternum, length of para-anal setae, presence and absence of spinelike setae and spurs respectively on any segment of leg IV.Female: Complete division of dorsal shield fonns two shields; podonotal shield longer than wide (IS5.1,um long, 96.35,um wide), with 17 pairs of simple setae; opisthonotal shield (141,um long, 68.15,um wide) with 15 pairs of simple setae;.j2 and j4 almost equal in length; transverse line between bases of setae J 1 absent; eight pairs of setae borne on lateral cuticle; j I, J5, S5 and Z5 arci21.15,um, 7.05,um, 14.1,um and 21.15,um in length respectively (Fig. 17).
Tritosternum with two proximally serrated lacinae (Fig. 18).Sternal shield (63.45 pm long along midline, 61.1 pm wide) with concave posterior margin, bears two pairs of subequal setae; first sternal setae placed on anterior projection of sternal shield; region anterior to projected portion of sternal shield desclerotized; endopodal shield extended anterolaterally from sternal shield on both side; metastemal setae shorter than setae st 1-5t3, placed on ventral membrane at level posterior to coxa IV; metastemal plate absent.Genital shield truncate posteriorly, with one pair of setae; transverse small "slit-like" marking present in the middle of genital shield (Fig. 19); anterior region of genital shield with epigynial process; two minute setae, Jvl and Jv2 situated on membrane anterior to ventri-anal shield.Ventri-anal shield longer than wide (91.65,um long, 56.08,um wide), anterior margin convex, fused posteriorly, with 4 paired and one exceptionally long post-anal setae (30.55,um); anal aperture of moderate size; membrane around ventri-anal shield with two pairs of setae; paired metapodal shield lie close to body margin.Small posterior portion of peritrematal shield lie freely forming a free pointed end.Stigma small, placed at mid-level of coxa IV; interscutal membrane.lineate.Tectum triangular in shape with denticulate margin (Fig. 20).Palp apotele two-tined.Movable cheliceral digit with two teeth, one smaller than the other; fixed cheliceral digit multidentate, teeth of uniform size (Fig. 21).Corniculi slender but shorter; palps stout; seven rows of deutostemal denticles present.
Remarks: Protogamasellus similiscuticalis sp.nov.shows resemblances with Protogamasellus scuticalis Genis et al. (1967) in the following aspect : j 1 longest of all podonotal setae; number of setae on podonotal and opisthonotal shield, shape of sternal 'shield and position of setae st 1 ; shape of tectum and ventri-anal shield, position of setae Jvl and Jv2.However, P. ,similiscuticalis differs markedly from the known species in having the following characters: J I and J4 not markedly longer than J2 and J3; discontinuous.transverse line between bases of setae J 1, shape of tritostemum, presence of peritrematal shield, minute Jvl and Jv2 and shape of cheliceral digit.
Female: Dorsum covered by two shields, roughly equal in length and width; podonotal shield 129.85,um in length and I03.4,um in width; opisthonotal shield 122.2,um in length and 98.7 pm in width; podonotal and opisthonotal shield with 16 and 15 pairs of setae respectively; eleven pairs of setae present on lateral membrane, all setae simple in nature; setae j I