Dichopelmus Keifer, 1959

Ferla, Noeli Juarez, 2017, Two eriophyoid mites (Acari: Eriophyoidea) associated with Ilex paraguariensis from Brazil, Zootaxa 4324 (2), pp. 363-370 : 367-370

Genus Dichopelmus Keifer, 1959

Figs. 5–7

Dichopelmus notus Keifer, 1959: 10 –11.

Genus diagnosis. Body fusiform, spindle–like and flattened; prodorsal shield subrectangular with naso rounded that projects well over the rostrum and hides it in dorsal view; setae sc present, placed in typical position on rear shield margin, directing setae divergently to the rear; all coxal and opisthosomal ventral setae present; legs with 6 segments (genu not fused with femur); with all usual setae and empodium divided.

FEMALE (n=8). Body fusiform, (212–219), (87–88) wide; brownish in life. Gnathosoma. Pedipalp coxal seta (ep) not seen; pedipalp genual seta (d) (13), chelicerae (19–21) and oral stylets (19–21). Scapular seta (7) near the rear shield margin, with small tubercles. Prodorsal shield (45–55), (63–72) wide, partially smooth with longitudinal lines running ahead from dorsal tubercles; Anterior prodorsal shield with a prominent lobe. Coxal plates. Coxae I and II without granules, with a few short lines. Coxa I (15) with anterolateral setae on coxisternum I (1b) (10–11) and proximal setae on coxisternum I (1a) (13–14); sternal line faint present. Coxa II (14–15) with proximal setae on coxisternum II (2a) (25–28); coxigenital area with (9–11) annuli, microtuberculate. Legs. Legs with all segments; Leg I (49–54), trochanter (5–6), femur (13–14), basiventral femoral seta (bv) (11–13); genu (3– 4); antaxial genual seta (l´´) (18–21); tibia (6–8), paraxial tibial seta (l´) (8–10); tarsus (5–6), seta ft´ (19–20), seta ft´´(20–22), seta u´ (3), tarsal empodium (em) (3–4) divided, 4–rayed at each side, tarsal solenidion (ω) (4–5) strongly knobbed. Leg II (51–53), trochanter (5), femur (14–15), basiventral femoral seta (bv) (17–18); genu (3–4); antaxial genual seta (l´´) (3–4); tibia (7); paraxial tibial seta (l´) absent; tarsus (5–6), paraxial fastigial tarsal seta (ft´) (5), antaxial fastigial tarsal seta (ft´´) (17–19), paraxial unguinal tarsal seta (u´) (3), tarsal empodium (em) (4– 5) divided, 4–rayed at each side, tarsal solenidion (ω) (5–6) strongly knobbed. Female genitalia. Female genitalia (19–22) long, (22–24) wide, cover flap with proximal area smooth and distal half area with 14–16 striae (longitudinal lines) extending over distal half, occupying almost entire cover flap; proximal seta on coxisternum III (3a) (13–14). Opisthosoma. Opisthosoma dorsally and ventrally each with total of (20–22) annuli, with microtubercles on rear annular margins; Lateral seta c2 (17–19); ventral seta I (d) (55–66) on ventral annuli 5; ventral seta II (e) (15–17) on ventral annuli 10; ventral seta III (f) (16–18) on 17th ventral annuli from anterior to posterior; accessory seta (h1) absent and caudal seta (h2) (51–54) tapering abruptly.

FIGURE 6. Dichopelmus notus : L1—Leg I; L2—Leg II.

Material examined. One female collected from Putinga (28°57´27.69´´S, 52°09´45.84´´O), Rio Grande do Sul, 19 February 2013, on Ilex paraguariensis . Seven females collected from Arvorezinha, Rio Grande do Sul, 19 February 2013 on Ilex paraguariensis . Specimens collected by Catiane Dameda and Angélica Bilhar Arce. The material examined was mounted on two slides. The slides are deposited at (ZAUMCN), UNIVATES.

Male. Not found.

Relation to host plant. This species lives on the leaf surface and is commonly known as rust mite on yerba mate. Its presence causes blight of new leaves, delaying their growth and causing their fall, directly affecting production. It has been responsible for considerable damage ( Coll & Caceres 1995; Santana et al. 1997; Meneguzzi et al. 2002; Gouvea et al. 2006).

Distribution. Argentina, Brazil.

Figures

FIGURE 5. Dichopelmus notus: D—dorsal habitus, female; V—ventral habitus, female.

FIGURE 7. Dichopelmus notus: A—View of prodorsum shield; B—Genital cover flap; C—View of opisthosoma showing microtubercle pattern. Scale bars: A, B and C = 20 µm