Hemipteroseius vikrami Menon

Menon, Pratibha, Joshi, Sushila & Hussain, Mohammad, 2011, A new species of Hemipteroseius (Acari: Otopheidomenidae) parasitic on Dysdercus (Hemiptera: Pyrrhocoridae) in India, Zootaxa 2800, pp. 53-63 : 54-58

Hemipteroseius vikrami Menon n. sp.

Female (n=10, Figs 1–4, 8 , 12, 13, 17 , 20–27 )

Dorsal idiosoma approximately 403 ± 26 long and 254.5 ± 11.5 wide, dorsum bearing two subequal shields, weakly ornamented. Podonotal shield roughly triangular, partly incised anteriorly, with posterior margin rectangular; opisthonotal shield roughly rectangular with posterior corners rounded and extended ( Figs 1 , 12 , 20 ). Podonotal shield 155 ± 3.5 long, bearing nine pairs of setae, some with bulbose/spatulate tips, others with simple blunt tips: j1 11 ± 2.2, j3 17 ± 2, j4 15 ± 1.7, j5 15.5 ± 2, j6 29.5 ± 2.7, z2 21 ± 2.2, z4 20.5 ± 2, z5 18 ± 2, s4 20 ± 2; j6 with bulbose/ spatulate tips ( Fig. 21 ). Opisthonotal shield 134.5 ± 10.1 long, bearing four pairs of setae: J2 20.5 ± 2.7, J5 2.5 ± 0, Z4 14 ± 1.3, Z5 38 ± 2; J5 minute and Z5 the longest pair of setae with bulbose/spatulate tips. Dorsal integument striated with four pairs of setae: r3 18 ± 1.1, s6 28.5 ± 3.3, R1 17 ± 1.1, JV5 18 ± 2; s6 with bulbose/spatulate tip; three pairs of pores present lateral and posterior to opisthonotal shield ( Fig. 22 ).

Ventral idiosoma. Tritosterum 42 ± 3.8, biramous, lacinae slightly-pilose, simple and small, unfused ( Fig. 3 ). Sternal shield poorly sclerotised, 67.4 ± 2.5 long, 72 ± 1 wide, slightly wider than long, and bearing one pair of setae attenuated distally and inserted on antero-lateral angles of sternal shield; sternal setae st2, st3 and st4 similar in shape and size to sternal setae st1, but inserted in the integument, lying posterior and lateral to sternal seta st1 and present within the limits of coxa III. Metasternal shields absent. Epigynal shield fenestrated, its anterior extension bearing many finely branched thickenings, shield parallel-sided medially, expanded posteriorly and somewhat convex on its posterior border, 103 ± 2.5 long, 77.2 ± 5 wide at the region of the epigynal setae; epigynal setae similar to sternal setae and inserted on posterolateral edges of shield. All sternal setae and epigynal setae approximately 35.5 ± 2 long ( Figs 2 , 13 , 24, 25 ). Ventral area striated transversally; metapodal plates present, narrow and elongate. Ventrianal shield mostly truncate anteriorly, sometimes slightly concave, 75 ± 3.8 long, 72 ± 3 wide, with a pair of pre-anal setae JV2 25.4 ± 0.5 long; anal opening terminal, surrounded by the usual three anal setae, para-anal seta 26.8 ± 2.1 long, post-anal seta dorsal, 24.5 ± 3.7; four pairs of opisthogastric setae inserted on the striated integument, JV1 22.4 ± 3.2, ZV2 18.8 ± 2.1, ZV3 16.6 ± 2.3 and JV4 16.2 ± 1.3 ( Figs 2 , 13 , 26 ). Peritreme short 77.2 ± 4.1, intestiniform; stigmata originating lateral to coxa IV, with peritreme extending anteriorly only to level of coxa II; peritremal plate prominent at the anterior tip only ( Fig. 16 ). Spermatheca 35 ± 3, paired, typical in form for the genus, distal canals terminating on or near posterior margins of coxa III.

Gnathosoma with harpoon-shaped corniculi ( Figs 8 , 23 ), distal end markedly swollen. All four pairs of capitular setae present. Chelicera (from base to tip without the digits) 73 ± 5.7, fixed digit rudimentary, movable digit 38.8 ± 1.7, bidentate, with a distal hook ( Figs 4 , 17 , 27 ).

Legs shorter than body, leg I: 211 ± 8.9, leg II: 177 ± 5.9, leg III: 168 ± 10.4 and leg IV: 205 ± 16.9. Chaetotaxy: femur I: 2 2/1 2/2 1, genu I: 1 2/0 0/1 1, tibia I: 1 2/1 0/1 1, femur II: 1 2/1 2/0 1, genu II: 1 1/0 1/0 1, tibia II: 1 1/0 1/1 1, femur III: 1 2/1 2/0 0, genu III: 1 1/0 1/0 1, tibia III: 1 1/0 1/0 1, femur IV: 1 1/1 1/0 0, genu IV: 1 1/1 1/0 0, tibia IV: 1 1/1 0/0 0. Macrosetae present on genu I–IV and femur I–II; macrosetae on genu I antero-dorsal, 40 ± 1.8, femur I postero-dorsal, 37.2 ± 3.8, genu II postero-dorsal, 38.6 ± 1.3, femur II postero-dorsal, 31.4 ± 1.5, genu III antero-dorsal 37.2 ± 1.7 and genu IV antero-dorsal 41.8 ± 3.9. All macrosetae with bulbose/spatulate tips.

Male (n=3, Figs 5–7 , 14,18, 19 , 28–33 )

Dorsal idiosoma 268 ± 1.73 long, 199 ± 2.8 wide. Dorsal shield shape and chaetotaxy similar to that of female ( Figs 5 , 28 ). Podonotal shield 151 ± 2 long, bearing nine pairs of setae, all simple setae, j6 with spatulate tips ( Fig. 30 ), j11 10 ± 1, j3 20 ± 1, j4 17.5 ± 1, j5 14.2 ± 0.5, j6 30.8 ± 0.5, z2 20.8 ± 0.5, z4 20.8 ± 0.5, z5 17.5 ± 1, s4 20.8 ± 2. Opisthonotal shield 98.3 ± 1.1 long, with four pairs of setae: J2 17.5 ± 0, J5 2.5 ± 0, Z4 12.5 ± 0, Z5 35 ± 2, J5 a microseta, Z5 longest, with spatula-like tip ( Fig.31 ). Dorsal integument striated, with four pairs of setae: r3 22.5 ± 1, s6 25.8 ± 1.1, R1 18.3 ± 1.1 and JV5 17.5 ± 0, s6 with bulbose/spatulate tip.

Ventral idiosoma. Sternitogenital shield 150 ± 3.5 long, 50 wide at the region of the first sternal setae; male genital opening distinct, on a level with anterior angles of coxa II; five pairs of simple setae on sternitogenital shield, 28.3 ± 1.1, the most anterior pair inserted posterior to the genital opening; posterior edge of shield not clear, perhaps slightly convex ( Figs 6 , 14 , 33 ). Anal shield 89.8 ± 8.2 long, expanded anteriorly, constricted medially, 48.8 ± 4.8 wide at the region of first pair of preanal setae; anal opening terminal; postanal setae 20 ± 1 long. Tritosternum 25.8 ± 2.8, palps, corniculi similar to female; spermadactyl process 26 ± 2.7, spear shaped ( Figs 7 , 19 , 32 ),

Gnathosoma . Chelicera (from base to tip without the digits) 71 ± 13.5, movable digit 31.5 ± 2.8, with single denticle apart from the distal hook ( Figs 7 , 18 ).

Legs. Leg I: 169 ± 2, leg II: 149 ± 2.5, leg III: 133 ± 3.7 and leg IV: 158 ± 1.5. Macrosetae present on genu I–IV and femur I–II; macrosetae on genu I antero-dorsal, 44.8 ± 1.7, femur I postero-dorsal, 46.3 ± 2.8, genu II postero-dorsal, 49 ± 2.4, femur II postero-dorsal, 43.8 ± 1.5, genu III postero-dorsal, 50.8 ± 2.2 and genu IV postero-dorsal, 57.5 ± 2.8. All macrosetae with bulbose/spatulate tips ( Fig. 29 ).

Eggs ovoid, whitish, 224 ± 4.4 long, 142 ± 6.4 wide ( Fig. 15 ).

Type material. Holotype: female, ex: Dysdercus cingulatus, Varanasi , 15 December 2009, coll. Mohd Hussain. Paratypes: 10 females and 3 males on 7 microscopic slide preparations, data same as above; 2 females ex: Dysdercus koenigii , New Delhi, 5 December 2007, coll. Pratibha Menon. Specimens deposited in National Pusa Collection, Division of Entomology, Indian Agricultural Research Institute, New Delhi.

Etymology. The specific name vikrami is in honour of Dr. Vikram Prasad, in recognition of his contributions to acarology in general and Otopheidomenidae in particular.

Remarks. The new species is an ectoparasite of Dysdercus koenigii and D. cingulatus . Specimens were seen adhering to the abdominal region under the wings ( Figs 9–11 ) of the hosts. It has been found only at Delhi and Varanasi, India. Hemipteroseius vikrami n. sp. is distinct from other known species of Hemipteroseius in the following combination of characters: dorsal shield divided, setae j6, s6 and Z5 with bulbose/spatulate tips, seta J1 absent, four pairs of sternal setae present, one pair on the sternal shield and three pairs on the integument posterolateral to the sternal shield, all macrosetae on genu I–IV, femur I–II with bulbose/spatulate tips, with positions given here as consistently observed in six out of ten specimens observed; one pair of pre-anal setae and a terminal anus.

In his description and illustrations of H. parvulus, Treat (1965) showed the ventral shield with two pairs of preanal setae, while in the key he had placed this species in the couplet for species bearing one pair of pre-anal setae. Costa (1968) referred to H. parvulus with one pair of pre-anal setae. However, the present authors have accepted H.

parvulus with two pairs of pre-anal setae based on Treat’s original description and illustrations. The essential morphological characters that distinguish H. vikrami from other species of Hemipteroseius are summarised in Table 1 and in the following key. Table 2 presents a list of all otopheidomenid mites with their distribution and hosts.

Figures

FIGURES 1 – 8. Hemipteroseius vikrami n. sp. 1. Female, dorsal view; 2. Female, ventral view; 3. Tritosternum; 4. Female chelicera with bidentate digit; 5. Male, dorsal view; 6. Male, ventral view; 7. Male chelicera with unidentate digit and spermatodactyl process; 8. Gnathosomal region showing harpoon shaped corniculi and capitular setae.

FIGURES 9 – 19. Hemipteroseius vikrami n. sp. 9. Mites on abdominal region under wings of Dysdercus sp. 10. Close-up of infested region showing eggs and adults; 11. Close-up of mites on Dysdercus sp.; 12. Female, dorsal view; 13. Female, ventral view; 14. Male, ventral view; 15. Egg; 16. Peritreme; 17. Female, movable digit with two denticles; 18. Male, movable digit with one denticle; 19. Male, spear-shaped spermatodactyl process.

FIGURES 20 – 27. Hemipteroseius vikrami n. sp., female. 20. Dorsal view; 21. Podonotal shield; 22. Opisthonotal shield; 23. Harpoon shaped corniculi and capitular setae; 24. Ventral idiosoma; 25. Sternal and genital shields; 26. Anal shield; 27. Bidentate chelicera and pedipalp.

FIGURES 28 – 33. Hemipteroseius vikrami n. sp., male. 28. Dorsal idiosoma; 29. Macroseta of Leg I, gnathosomal region, tectum and part of podonotal region; 30. Podonotal region; 31. Opisthonotal region; 32. Ventral view with spear-shaped spermatophoral process, harpoon shaped corniculi, capitular setae and part of tritosternum; 33. Ventral idiosoma.