Aculus lalithi, Xue & Zhang, 2008

Xue, Xiao-Feng & Zhang, Zhi-Qiang, 2008, New Zealand Eriophyoidea (Acari: Prostigmata): an update with descriptions of one new genus and six new species, Zootaxa 1962 (1), pp. 1-32 : 23-24

Aculus lalithi sp. nov.

( Figs 12 & 13 )

Description. FEMALE: (n = 10) Body fusiform, 191 (180–192), 65 (63–66) wide, 55 (53–56) thick; light yellow. Gnathosoma 23 (21–24), projecting obliquely down, pedipalp coxal seta (ep) 3 (3–4), dorsal pedipalp genual seta (d) 5 (5–6), cheliceral stylets 21 (20–21). Prodorsal shield subtriangular, 36 (35–36), 58 (55–58) wide, smooth; anterior shield lobe broad. Median, admedian and submedian lines absent. Scapular tubercles on rear margin, 29 (28–29) apart, scapular setae (sc) 17 (15–18) projecting posterior. Coxal plates smooth; anterolateral setae on coxisternum І (1b) 5 (5–6), 11 (11–12) apart, proximal setae on coxisternum І (1a) 15 (14–16), 10 (10–11) apart, proximal setae on coxisternum І (2a) 25 (22–27), 22 (21–22) apart. Prosternal apodeme 7 (7–8). Legs with usual series of setae. Legs І 28 (26–29), femur 7 (7–8), basiventral femoral seta (bv) 8 (6–8); genu 5 (4–5), antaxial genual seta (l'') 21 (20–23); tibia 7 (6–7), paraxial tibial seta (l') 5 (5–6), seta located 1/3 from proximal tibial margin; tarsus 6 (5–6), seta ft'' as long as seta ft', seta u' short; tarsal empodium (em) 4 (4–5), simple, 4-rayed, tarsal solenidion (ω) 5 (4–5), knobbed. Legs І 26 (24–27), femur 7 (6–7), basiventral femoral seta (bv) 6 (5–6); genu 4 (3–4), antaxial genual seta (l'') 5 (5–6); tibia 5 (4–5); tarsus 6 (5–6), seta ft'' as long as seta ft', seta u' short; tarsal empodium (em) 4 (4–5), simple, 4-rayed, tarsal solenidion (ω) 5 (4–5), knobbed. Opisthosoma: opisthosoma dorsally with 26 (25–28) annuli, smooth, ventrally with 49 (45–56) annuli, with round microtubercles. Setae c2 26 (24–27) on ventral annulus 9 (7–9), 46 (44–46) apart; setae d 31 (30–33) on ventral annulus 21 (19–21), 29 (27–29) apart; setae e 17 (15–19) on ventral annulus 32 (28–32), 15 (14–15) apart, setae f 16 (14–17) on 7th ventral annulus from rear, 17 (16–17) apart. Setae h1 absent. Female genitalia 12 (12–13), 20 (19–21) wide, coverflap with 12 longitudinal ridges, proximal setae on coxisternum ІІ (3a) 16 (15–16), 15 (15–16) apart.

MALE: (n = 3) Body fusiform, 158–163, 54–55 wide, 47–48 thick; light yellow. Gnathosoma 19–20, projecting obliquely down, pedipalp coxal setae (ep) 3–4, dorsal pedipalp genual seta (d) 4–5, cheliceral stylets 17–18. Prodorsal shield subtriangular, 30–32, 50–53 wide; smooth; anterior shield lobe broad. Scapular tubercles on rear margin, 22–23 apart, scapular setae (sc) 16–17 projecting posterior. Coxal plates smooth; anterolateral setae on coxisternum І (1b) 5–6, 7–8 apart, proximal setae on coxisternum І (1a) 12–13, 7–8 apart, proximal setae on coxisternum І (2a) 20–21, 16–18 apart. Prosternal apodeme 7–8. Legs with usual series of setae. Legs І 22–25, femur 5–6, basiventral femoral seta (bv) 5–6; genu 3–4, antaxial genual seta (l'') 15–17; tibia 5–6, paraxial tibial seta (l') 4–5, seta located 1/3 from proximal tibial margin; tarsus 4–5, seta ft'' as long as seta ft', seta u' short; tarsal empodium (em) 4–5, simple, 4-rayed, tarsal solenidion (ω) 4–5, knobbed. Legs І 20–21, femur 5–6, basiventral femoral seta (bv) 5–6; genu 3–4, antaxial genual seta (l'') 4–5; tibia 4–5; tarsus 4–5, seta ft'' as long as seta ft', seta u' short; tarsal empodium (em) 4–5, simple, 4-rayed, tarsal solenidion (ω) 4–5, knobbed. Opisthosoma: opisthosoma dorsally with 23–25 annuli, smooth, ventrally with 45–46 annuli, with round microtubercles. Setae c2 21–22 on ventral annulus 7–8, 38–39 apart; setae d 26–28 on ventral annulus 15–16, 24–25 apart; setae e 12–13 on ventral annulus 23–25, 10–11 apart, setae f 11–13 on 6th ventral annulus from rear, 12–13 apart. Setae h1 absent. Male genitalia 15–16 wide, proximal setae on coxisternum ІІ (3a) 8–10, 13–14 apart.

Type material. Holotype, female (marked H), from Melicope ternata (Rutaceae) , Waitakere Ranges, Auckland, New Zealand, 6 November 1999, coll. N.A. Martin. Paratypes, 9 females and 3 males, with the same data as holotype. Specimens deposited in NZAC.

Relation to host. Associated with, but probably not causing white leaf erineum.

Etymology. This species is named after Dr Lalith Kumarasinghe (Plant Health & Environment Laboratory, Investigation and Diagnostic Centre, MAF Biosecurity, Auckland, New Zealand)

Differential diagnosis. This species is similar to Aculus rumexis Xue, Song & Hong, 2008 , but can be differentiated from the latter by the following: 1) prodorsal shield smooth (median, admedian and submedian lines present in A. rumexis ), 2) coxal area with smooth (coxal area with granules in A. rumexis ), and 3) setae h1 absent (setae h1 present in A. rumexis ).

Figures

FIGURE 12. Aculus lalithi sp. nov. D, dorsal view of female; CG, coxae and female genitalia; L1, leg І; L2, leg І; em, empodium.

FIGURE 13. Aculus lalithi sp. nov. L, lateral view of female; CGM, coxae and male genitalia; LO, lateral microtubercles.