Proctolaelaps pygmaeus (Müller), Muller

Abo-Shnaf, Reham I. A. & De Moraes, Gilberto J., 2016, Proctolaelaps species (Acari: Mesostigmata: Melicharidae) from Egypt, with description of a new species and complementary descriptions of other five species, Zootaxa 4162 (3), pp. 479-503 : 495-496

Proctolaelaps pygmaeus (Müller)

( Figs 48–56 )

Gamasus pygmaeus Müller, 1859: 30 .

Proctolaelaps pygmaeus .— Chant, 1963: 259; Ehara, 1964: 387; McGraw & Farrier, 1969: 90; Bregetova, 1977: 213; Zaher, 1986: 61; Jordaan & Loots, 1987: 53; Halliday et al., 1998: 37; Gupta, 2003: 8; Faraji, 2011: 26; Moraes et al., 2016: 223 .

Proctolaelaps (Proctolaelaps) pygmaeus .— Ryke, 1964: 341; Karg, 1985: 190; Karg, 1988: 447.

Hypoaspis hypudaei Oudemans,1902: 21 . Synonymy by Oudemans, 1916: 299.

Hypoaspis hypudaei .— Athias-Henriot, 1961: 451; Ryke, 1964: 341; Karg, 1985: 191; Zaher, 1986: 61; Farrier & Hennessey, 1993: 45.

Garmania (Garmania) hypudaei .— Westerboer, 1963: 360.

Specimens examined. One female from unknown substrate, at Giza governorate (29° 13' E, 28° 45' N), August 5, 1975 and seven females from manure, at the same locality, September 5, 1978, both by unknown collector and deposited in the mite reference collection of Zoology and Agricultural Nematology Department, the Faculty of Agriculture , Cairo University , Giza governorate. Two females from litter underneath mango, at Senuris (30° 15' E, 29° 6' N), Fayoum governorate, July 2, 2002 ; two females from soil, at the same locality and date; one female from litter underneath apricot, at the same locality, May 13, 2003 ; one female from litter underneath fig, at the same locality, November 16, 2003 ; four females from litter underneath cucumber, at the same locality, February 2, 2005; one female from litter underneath poinsettia, at the Faculty of Agriculture Farm (29° 13' E, 28° 45' N), Cairo University , Giza governorate, January 1, 2008; two females from litter underneath J. adhatoda , at Orman Botanical Garden (31° 12' E, 30° 1' N) , Giza governorate, February 27, 2006 ; one female from litter underneath G. jasminoides , at the same locality, May 7, 2006 ; one female from litter underneath A. marginata , at the same locality, December 5, 2006 ; one female from litter underneath basil, at the same locality and date; one female from litter underneath rose, at the same locality, January 18, 2007 ; one female from litter underneath C. splendens , at the same locality and date; three females from litter underneath Strelitzia spp., at the same locality, June 18, 2012 .

Adult female (six specimens measured)

Dorsum of idiosoma ( Fig. 48 ): dorsal shield 404 (359–435) long and 247 (217–295) wide at widest level. Podonotal region of the dorsal shield reticulate, with 23 pairs of setae (j1–j6, z1–z6, s1–s6, r2–r6), three pairs of distinguishable lyrifissures and two pairs of distinguishable pores. Opisthonotal region reticulate, but with reticules more transversely elongate between right and left setae of the Z series than on podonotal region and remaining of opisthonotal region; with 20–21 pairs of setae (J1–J5, Z1–Z5, S1–S5, R1–R5; R6 on or off the shield), nine pairs of distinguishable lyrifissures and three pairs of distinguishable pores. Most dorsal shield setae of uniform length and shape and slightly longer than distance to respective subsequent setae, aciculate and smooth, except Z5, serrate. Unsclerotised lateral cuticle with four pairs of setae (UR1, UR3, UR4, UR5); all aciculate and smooth; each seta set on a tiny platelet, and with a lyrifissure (Rp) between R3 and R4. Setal lengths: j1 32 (28–33), j2 40 (37–43), j3 51 (50–53), j4 52 (50–57), j5 51 (48–53), j6 52 (49–55), z1 21 (19–24), z2 42 (39–44), z3 56 (53–58), z4 55 (52–58), z5 57 (54–58), z6 52 (46–55), s1 36 (33–38), s2 44 (41–46), s3 47 (43–53), s4 51 (48–56), s5 56 (52–60), s6 48 (44–55), r2 41 (38–43), r3 42 (38–45), r4 40 (36–42), r5 40 (36–45), r6 35 (31–41), J1 49 (46–53), J2 49 (43–55), J3 51 (45–56), J4 56 (50–60), J5 24 (22–28), Z1 52 (48–56), Z2 45 (39–50), Z3 50 (45–55), Z4 52 (45–55), Z5 57 (55–61), S1 43 (40–48), S2 44 (39–48), S3 42 (38–45), S4 45 (41–48), S5 41 (38–45), R1 32 (31–35), R2 31 (28– 35), R3 32 (29–36), R4 34 (31–36), R5 33 (31–35), R6 35 (32–37), UR1 26 (23–27), UR3 26 (24–29), UR4 31 (29– 33), UR5 33 (30–36).

Venter of idiosoma ( Figs 49–51 ): all setae aciculate and smooth. Base of tritosternum 14 (13–15) long and 11 (10–11) wide at medium level; laciniae 65 (60–69) long, divided for about 60 (57–61)% of their total length. Presternal region transversely striate. Sternal shield fused with anterior portion of endopodal plate, with a pair of pore (gst1) on distal end of extension between coxae I–II, mostly smooth, with sparse anterior and lateral striae and with a quadrangular anteromedian ornamentation; 97 (89–103) long and 102 (88–112) wide at level of st2, with three pairs of setae (st1–st3) and two pairs of lyrifissures. Posterior portion of endopodal plate represented by a triradiate fragment between coxae III–IV. Metasternal plate rectangular, with the fourth pair of sternal seta (st4); lyrifissure iv3 indistinguishable. Genital shield smooth, 159 (145–169) long, including hyaline flap; with posteriorly divergent lateral margins; posterior margin convex, 98 (89–103) wide at posterior corners, bearing genital setae (st5); distance between genital setae 75 (66–82); paragenital lyrifissures (iv5) on unsclerotised cuticle, posterolaterad of st5. Anal shield rounded, with parallel arched striae anteriad of anal opening, 92 (86–100) long and 82 (77–85) wide at widest level, with circumanal setae, with a pair of marginal pores posterolaterad of paraanal setae; anal opening large, 46 (43–48) long including frame. Exopodal plate distinct from posterior margin of coxa IV to anterior margin of coxa II; with a pore near posterior end. Unsclerotised cuticle around anal shield with JV1–JV5, ZV1–ZV5 and four pairs of lyrifissures; each opisthogastric seta off anal shield set on a tiny platelet. With two pairs of metapodal plates, the inner smaller (in four specimens, fused on one side). Setal lengths: st1 45 (42– 48), st2 44 (41–45), st3 42 (38–45), st4 35 (31–38), st5 32 (30–36), JV1 34 (30–36), JV2 44 (40–46), JV3 43 (41– 46), JV4 36 (32–39), JV5 46 (41–49), ZV1 29 (27–32), ZV2 38 (36–39), ZV3 34 (29–36), ZV4 35 (31–36), ZV5 34 (31–36), para-anal 29 (25–31) and post-anal 36 (33–38).

Peritrematic plate and peritreme ( Figs 48, 51 ): peritrematic plate fused with dorsal shield at level of s2 and abutting to exopodal plate beside coxa IV; with a lyrifissure and a pore in region between coxae II–III (ip2, gp1), with a pore (gp2) behind stigma (lyrifissures not distinguishable). Peritreme extending forward to level of z1.

Spermatheca ( Fig. 52 ): spermathecal apparatus lightly sclerotised, total length about 180; barely distinguishable near insemination pore, fading afterward to become most visible as an ellipsoidal section about 23 (23–24) long which is then followed by a section, about 110 long, consisting of seemingly four ducts involved by a thin sheath; insemination pore apparently on posterior region of coxa IV.

Gnathosoma ( Figs 53–55 ): anteromedian region of epistome rounded, with margin denticulate. Cheliceral dorsal and antiaxial lyrifissures and dorsal seta distinct; hyaline rim on paraxial face of chelicera with about ten teeth, at a level slightly higher than row of teeth on fixed digit. Fixed digit 28 (27–33) long, with four relatively large teeth followed by four tiny subapical teeth and large antiaxial membranous lobe; movable digit 27 (26–30) long, with three teeth, the most basal tiny. Hypostome with h1 much thicker than h2, h3 and sc; with a small, spinelike membranous process near basal paraxial margin of corniculus. Deutosternum with seven transverse lines, delimited by subparallel lateral lines from first to sixth transverse lines; first (most distal) line smooth; second to fifth lines with 3–4 denticles each, sixth with 17 and seventh with 20 denticles. Corniculi slightly convergent, distally pointed, about 25 (23–28) long and 10 (8–11) wide at the base. Setal lengths: h1 29 (28–30), h2 22 (20–24), h3 28 (25–31) and sc 35 (32–38); palp trochanter setae av 24 (22–25) and pv 18 (17–19).

Legs ( Fig. 56 ): pretarsi I–IV each with a pair of claws and pulvillus with three rounded lobules. Leg lengths: I, 454 (413–497); II, 363 (324–396); III, 380 (355–399) and IV, 562 (520–596). Leg chaetotaxy—genua: I—2 3/2 3/ 1 2; II—2 3/1 2/1 2; III—2 2/1 2/1 1; IV—2 2/1 3/0 1; tibiae: I—2 3/2 3/1 2; II—2 2/1 2/1 2; III—2 1/1 2/1 1; IV— 2 1/1 3/1 2. Without distinct macrosetae.

Previous records from Egypt. Lower Egypt (Behira governorate) and Upper Egypt (Beni Suef governorate) ( Zaher, 1986).

Remarks. Proctolaelaps pygmaeus was originally described from a female collected in the Czech Republic. The original description was brief, with no illustrations. Complementary descriptions of this species have been provided in the literature ( Moraes et al., 2016). The specimens collected in the present work fit the characterisation of Egyptian specimens provided by Zaher (1986), who however did not provide measurements. As reported by Chant (1963), Westerboer (1963) and Zaher (1986), h1 is distinctly stouter than other hypostomal setae. As in the present study, the redescription provided by Westerboer (1963), but not that provided by Chant (1963), also shows a small, spine-like membranous process near basal paraxial margin of corniculus. Measurements of idiosomal setae provided by Westerboer (1963) for European specimens correspond to the minimum values of the specimens examined in this study, but those specimens are on the average also smaller than the latter. Japanese specimens may have shorter setae than specimens of this study; measurements provided for those specimens by Ehara (1964) for r3, Z1, Z5 and JV5 are about 10–25% shorter than the minimum values observed in the specimens collected in this study; that author did not mention the size of the Japanese specimens. He referred to the presence of a macroseta on basitarsus IV (72 long), which is absent in the specimens of this study; it is assumed that he could actually be referring to ad2 of tarsus IV, which in our specimens is about 70 long and only slight longer than neighboring setae. Differently from our specimens, the peritrematic plate is mentioned by Chant (1963) and Ehara (1964) not to be fused with exopodal plate posteriorly. However, the illustrations provided by the first author show those plates to be in contact near coxa IV. Egyptian specimens seem to differ from Australian specimens characterised by Halliday et al. (1998) and from European specimens characterised by Westerboer (1963) by having Z5 slightly serrate. Mathys & Tencalla (1959) studied the biology of this species (mentioned as P. hypudaei ), that they found associated with the spider mite Tetranychus urticae Koch on apple trees. They mentioned that instead of sucking the prey as phytoseiids do, this melicharid would totally devour specimens of T. urticae . As also reported by Halliday et al. (1998), the specimens collected in this study have abundant fungus spores in their digestive tract, suggesting them to feed on solid material, which could be related to their large anal opening.

Figures

FIGURES 48 – 56. Proctolaelaps pygmaeus, female: 48. Dorsum of idiosoma; 49. Tritosternum; 50. Venter of idiosoma; 51. Peritrematic and exopodal plates; 52. Spermathecae; 53. Epistome; 54. Chelicera; 55. Hypostome; 56. Leg IV.