Afrophilodana africana, Kontschán, Jenő & Seeman, Owen, 2011

Kontschán, Jenő & Seeman, Owen, 2011, Afrophilodana africana n. gen, n. sp. (Acari: Mesostigmata) from Kenya: the second species of the family Philodanidae, Zootaxa 2753, pp. 42-52 : 44-51

Afrophilodana africana sp. nov.

( Figs 1–22 )

Material examined. Holotype. Female, Kenya, Shimba Hills National Park, near to lodge, 10 March 2001; litter and soil of montane rain forest. S. Mahunka and L. Mahunka-Papp coll. Paratype. Female, locality and date same as holotype.

Description. Female. Measurement of holotype (measurement of paratype): length 880 (920), width at level of coxae IV 920 (950), body rounded posteriorly.

Dorsal idiosoma ( Figs 1 , 16 ). Dorsum covered by holodorsal plate with podonotal (429 [455] long) and opisthonotal regions (479 [465] long) delineated by line of fusion, bearing numerous short, simple setae ( Figs 1, 2 ). Setae longer and more numerous in lateral areas of plates and shorter and sparser in mesal area. Sculptural pattern on both plates very finely reticulate, except smooth where podonotal and opisthonotal plates connect. Dorsal plate completely separated from lateral margin by a band of membranous cuticle; lateral margin with smooth simple setae placed on small platelets.

Ventral idiosoma ( Figs 3 , 17 ). Sclerotisation extensive, forming large contiguous plates, with reticulate pattering and separated by narrow bands of membranous cuticle. Tritosternal base narrow, laciniae serrate and separate along most of their length ( Fig. 7 ). Presternal shield present, reticulate, bearing simple st1, 12 (10) long and stp1. Sternal shield reticulate, with several oval pits, one pair of simple setae (st2, 14 [9] long) and stp2; fused to endopodal shields laterally. Endopodal shield with reticulate pattern anteriorly, smooth posteriorly, bearing one pair of setae (21 [16] long) between coxae III and IV; tentatively assigned as st4. One pair of long simple setae (60 [55] long) situated on membranous cuticle between sternal and mesogynal shields, in approximate sternogynal position; tentatively assigned as st3. Mesogynal shield subtriangular, rounded, 147 (130) long, 189 (170) wide. Latigynal shields subtriangular, 199 (193) long, 95 (101) wide, bearing three pairs of simple setae ( Figs 5 and 18 ). Internal genitalia complex, not clearly visible, but at least comprising large membranous area above genital shields; this area comprises a medial sac and a short posterior tube leading to a small sac, itself with an accessory sac ( Figs 6 and 19 ). Ventral plate hypertrichous, reticulate, with numerous small oval pits. Ventrianal plate broadly trapezoidal, 165 (160) long, 763 (740) wide, reticulate, hypertrichous; anus narrow, placed anteromedially; one pair of large gland-like structures at posterolateral margin. One pair of oval pores situated laterally from anus ( Fig. 4 ). Peritrematal plate fused with metapodal region and ventral shield, peritremes straight, extending past the level of coxa I. Marginal shields separated from ventral, ventrianal and peritrematal shield posteriorly, reaches peritremes at level of coxa II – III; marginal shields reticulate, posteriorly bearing several short simple setae.

Gnathosoma ( Fig. 7 ). Corniculi 12 long, setiform, set into large pits on the upper surface of the hypostome ( Fig. 8 ). Gnathotectum with serrate margin, several rows of denticles, and weak medial keel ( Fig. 9 ). Internal malae with pilose margins, setae h1–h4 serrate, h1 thicker and more serrate than other setae, seta h3 only slightly lateral of line formed by h1–h2. Palp tibia and tarsus fused, apotele with two tines ( Figs 10 , 25 ). Setae on palp trochanter, genu and tibia serrate, thin; setae on palp tibiotarsus serrate except for eight blunt terminal sensory setae and one posterolateral tactile seta smooth. Palp setal counts 2, 5, 6, 17.

Chelicerae. Fixed digit regressed, a tiny thumb-like process 10 long; fixed digit also bears at least three excrescences: a small membranous triangular excrescence 15 long, a long filamentous excrescence 90 long, and a long thin process at least 90 long (probably broken; detached part on slide and 80 long). Moveable digit strongly hooklike and with minute medial tooth and a pair of minute basal teeth; two excrescences: one filamentous, seemingly originating on the fixed digit and becoming separate upon reaching the moveable digit, and with one smooth margin and one papillate margin; the other excrescence membranous, smooth, and probably with long thin process (broken in specimen). Both excrescences broken in photographed specimen ( Figs 11 , 20 ).

Legs. Setae on coxae finely pilose, other setae smooth. Surface of legs with reticulate pattern. Claws absent from each leg, ambulacrum present on legs II – IV ( Figs 12 – 15 and 21 – 24 ). Leg setal counts: trochanters 6, 5, 5, 5; femora 12, 9, 7, 8; genua 10, 12, 12, 11; tibiae 9, 10, 10, 10; tarsi 30 or 31, 17, 17, 19. Tarsal tip II – IV with one or two additional small, fine seta-like structures; not clear in specimens examined (ad1 and pd1 of Baker & Seeman (2007)). Leg chaetotaxy in Tables 2–4 .

Male, nymphs and larvae unknown.

Afrophilodana Philodana Micromegistus Promegistus Femur I

Afrophilodana Philodana Micromegistus Promegistus Host. The two specimens were collected from soil sample, hence their hosts are unknown, because large arthropods were not represented in the investigated sample.

Etymology. The name of the new species refers to the continent where the type specimens were collected.

Remarks. Kethley (1977a) described the chelicerae of the both sexes of Philodana , but the drawing of the male chelicera ( Kethley 1977a: Fig. 8 ) is similar to our female chelicerae. We assume that this is not sexual dimorphism but rather distortion and rotation of his original specimens.

Figures

FIGURES 1 – 2. Afrophilodana africana gen. et sp. nov., female. 1. Dorsal aspect; 2. Dorsal pattern and setae (Scale bar: 100 µm).

FIGURES 3 – 6. Afrophilodana africana gen. et sp. nov., female. 3. Ventral aspect; 4. Anal region; 5. Intercoxal region; 6. Genital complex (Scale bar: 100 µm). Shield abbreviations: En = endopodal; Lg = latigynal; Mg = mesogynal; Ps = presternal; St = sternal.

FIGURES 7 – 15. Afrophilodana africana gen. et sp. nov., sp. nov., female. 7. Tritosternum and ventral view of gnathosoma; 8. Corniculus; 9. Gnathotectum; 10. Palp lateral view; 11. Chelicera. 12. Leg I; 13. Leg II; 14. Leg III; 15. Leg IV. (Scale bar: 50 µm for 7 – 11, 100 µm for 12 – 15).

FIGURES 16 – 25. Microscope photos of Afrophilodana africana gen. et sp. nov., female. 16. Dorsal aspect; 17. Ventral aspect; 18. Intercoxal region; 19. Genital complex; 20. Chelicera; 21: Tarsus of leg I; 22. Tarsus of leg II; 23. Tarsus of leg III; 24. Tarsus of leg IV; 25. Lateral view of palp (Scale bar: 100 µm).