Acerimina tiliaceae Mohanasundaram & Sharma, 1984, rec. nov.

(Figs 1–5, Table 1)

Acerimina tiliaceae Mohanasundaram & Sharma, 1984: 19‒21.; Amrine & Stasny, 1994: 99. Morphology of adult

Supplementary description. Female (n = 12): Body vermiform, elongate, 170‒230, 35‒46 wide, 41‒45 thick; light yellow. Gnathosoma projecting obliquely downwards, cheliceral stylets 11*; palp 14‒17, pedipalp coxal setae ep 3*, dorsal pedipalp genual setae d 4*, non-bifurcate (simple), palp tarsal ventral setae v absent.

Prodorsal shield. 20‒25, 25‒30 wide, semicircular; median and admedian lines complete, submedian lines present in anterior half, other region ornamented with granules and weakly lines. Scapular tubercles on rear shield margin, 15‒18 apart; scapular setae sc 12‒16, projecting backward.

Coxigenital region with 5 semiannuli, bearing tiny microtubercles between coxae and external genitalia. Coxal area with many granules, prosternal apodeme absent. Coxisternal setae 1b absent; 1a 12*, 10* apart; 2a 30*, 20* apart; 1a -2a 7* apart.

Legs. Leg I 28*, femur 10*, basiventral femoral setae bv 10*; genu 5*, antaxial genual setae l″ 15*; tibia 5*, paraxial tibial setae l′ 4*; tarsus 8*, paraxial fastigial tarsal setae ft′ 5*, antaxial fastigial tarsal setae ft″ 18*, setae u′ 4*; tarsal empodium em 5*, 7-rayed, tarsal solenidion ω 6*, rod-like. Leg II 30*, femur 10*, bv 7*; genu 4*, l” 9*; tibia 4*; tarsus 7*, setae ft′ 10*, ft″ 19*, u′ 3*; tarsal empodium em 5‒6, 7-rayed, tarsal solenidion ω 9*, rod-like.

Opisthosoma. Opisthosoma with 67‒68 subequal dorsal and ventral semiannuli, with elliptical to linear microtubercles on the rear margin of annuli, but reducing in the posterior part of dorsal semiannuli. Setae c2 12*, on ventral annulus 11*, 41‒42 apart; setae d 28‒30 on ventral annulus 24*, 38‒39 apart; setae e 30‒35 on ventral annulus 42*, 30 apart; setae f 20* on 6 th ventral annulus from rear, 14 apart; setae h1 4*, h2 50‒55.

External genitalia. 12*, 19* wide, coverflap with 16‒18 longitudinal striae and with constriction in the insertion of setae 3a; setae 3a 10*, 12* apart.

Internal genitalia. Spermathecae sub-quadrangularovoid, oriented posterolaterad; spermathecal tubes normal, relatively short; transverse genital apodeme trapezoidal, distally folded.

Male (n = 3): Body vermiform, elongate, 167‒200, 45‒46 wide, 43‒44 thick; light yellow. Gnathosoma. Cheliceral stylets 10*, pedipalp coxal setae ep 2*, dorsal pedipalp genual setae d 3*, palp tarsal ventral setae v absent.

Prodorsal shield 24‒26, 35 wide; prodorsal shield ornamentation similar to that of female. Scapular tubercles 19‒20 apart; scapular setae sc 9‒11.

Coxigenital region with 4 semiannuli between coxae and external genitalia. Coxal area ornamentation similar to that of female. Coxisternal setae 1a 14‒15, 9‒10 apart; 2a 29‒31, 19‒20 apart; 1a -2a 7‒8 apart.

Legs. Leg I 19‒20, femur 6‒7, setae bv 3‒5; genu 3‒4, setae l″ 17‒18; tibia 3*, setae l′ 4; tarsus 5‒6, setae ft′ 10‒11, setae ft″ 15‒17, setae u′ 3; em 5*, 7-rayed, ω 6*, rod-like. Leg II 19‒20, femur 6‒7, setae bv 4‒6; genu 3*, setae l″ 3‒4; tibia 3*; tarsus 5*, setae ft′ 3‒4, ft″ 17‒18, u′ 2‒3; em 5*, 7-rayed, ω 7*, rod-like.

Opisthosoma. Opisthosoma with 64‒67 dorsal and 66‒73 ventral semiannuli. Setae c2 11‒13, on ventral annulus 9‒12, 39* apart; setae d 32‒36 on ventral annulus 20‒24, 31‒34 apart; setae e 31‒35 on ventral annulus 37‒43, 23‒25 apart; setae f 16‒17 on 6 th ventral annulus from rear, 12‒14 apart; setae h1 4*, h2 37‒42.

External genitalia. Genital area about 16*, 20‒21 wide, with granules ornamentation; setae 3a 6‒8, 16‒17 apart.

Morphology of nymph

Description. (n = 5): Body vermiform, 120‒138, 27‒30 wide; whitish. Gnathosoma 15‒16, projecting obliquely downwards, cheliceral stylets 14‒15, pedipalp coxal setae ep 2*, dorsal pedipalp genual setae d 4*, subapical pedipalp tarsal setae v absent. Prodorsal shield 16‒18, 17‒21 wide. Median line present in posterior half part, admedian lines complete, submedian lines present but broken in the middle, other region ornamented with weakly lines but without granules. Scapular tubercles 12‒13 apart, setae sc 12‒15. Coxal plates with coarse granules; proximal setae on coxisternum І 1a 4‒5, 5‒7 apart; proximal setae on coxisternum ІІ 2a 11‒12, 13‒16 apart; 1a-2a 5* apart. Prosternal apodeme absent. Leg І 13*, femur 4*, setae bv 4*; genu 2*, setae l″ 7*; tibia 2‒3, setae l′ 3*; tarsus 5*, setae ft′ 9*, setae ft″ 12*, setae u′ 1*; tarsal empodium em 4*, simple, 6-rayed, tarsal solenidion ω 4*, rod-like. Leg ІІ 13*, femur 5*, setae bv 3*; genu 2*, setae l″ 3*; tibia 2*; tarsus 4*, setae ft′ 2*, setae ft″ 12*, setae u′ 1*; tarsal empodium em 3*, simple, 6-rayed, tarsal solenidion ω 5*, rod-like. Opisthosoma dorsally with 58‒60 annuli, with rounded microtubercles on rear annular margin, ventrally with 55‒56 annuli, with round to linear microtubercles. Setae c2 5‒9, on ventral semiannulus 12*, 26‒28 apart; setae d 16‒20, on ventral semiannulus 23*, 23 apart; setae e 20‒21, on ventral semiannulus 35‒37, 16* apart; setae f 9‒10, 10* apart, on 5‒6 th ventral semiannulus from rear; setae h1 2‒3, h2 28‒29. Setae 3a 4‒5, 5‒6 apart; no genital organ.

Morphology of larva

Description. (n = 3): Body vermiform, 87‒105, 25‒28 wide; whitish. Gnathosoma 14*, projecting downwards, cheliceral stylets 10‒11, pedipalp coxal setae ep 1*, dorsal pedipalp genual setae d 2*, subapical pedipalp tarsal setae v absent. Prodorsal shield 15‒16, 17‒20 wide; median line anteriorly Y-shaped, admedian lines complete, submedian lines absent, other ornamentation absent. Scapular tubercles 15 apart, setae sc 4*, projecting forward. Coxal plates without granules; proximal setae on coxisternum І 1a 2*, 5 apart; proximal setae on coxisternum ІІ 2a 6‒8, 13‒14 apart; 1a-2a 5 apart. Prosternal apodeme absent. Leg І 10‒11, femur 2, setae bv 3*; genu 2, setae l″ 4*; tibia 1‒2, setae l′ 1*; tarsus 2*, setae ft′ 2*, setae ft″ 4*, setae u′ 1*; tarsal empodium em 3*, simple, 4-rayed, tarsal solenidion ω 3*, rod-like. Leg ІІ 10*, femur 2‒3, setae bv 2*; genu 2*, setae l″ 3.22; tibia 1*; tarsus 3*, setae ft′ 1*, setae ft″ 6*, setae u′ 1*; tarsal empodium em 2‒3, simple, 4-rayed, tarsal solenidion ω 4*, rod-like. Opisthosoma dorsally with 39‒49 annuli, with rounded microtubercles on rear annuli, region between scapular tubercles and level of setae c2 with irregular granules and weakly developed annuli; ventrally with 37‒39 annuli, with round to linear microtubercles. Setae c2 4‒8, on ventral semiannulus 9*, 25 apart; setae d 9*, on ventral semiannulus 15‒17, 19‒20 apart; setae e 9‒10, on ventral semiannulus 23‒25, 19* apart; setae f 8‒9, 14 apart, on 5‒6 th ventral semiannulus from rear; setae h1 2*, h2 12‒15. Setae 3a 2‒3*, 5 ‒6 apart; no genital organ; anal lobe undivided, not bilaterally separated into two lobes.

Material examined. 12 females, 3 males, 5 nymphs and 3 larvae (23 slides) (slide nos. NJAUQ 611.1‒23), collected from Hibiscus tiliaceus L. (Malvaceae), Jiangdong Avenue, Haikou City, Hainan Province, China, 20°1′48″N, 110°27′36″E, elevation 4 m, 10 August 2025, coll. Hui-Hua Hao.

Host plant. Hibiscus tiliaceus L. (Malvaceae).

Relation to host. This mite damages the host by inducing cauliflower-like galls that develop predominantly on the abaxial leaf surface, while on the adaxial surface they are expressed as vibrant red areas (Figs 4 & 5).

Distribution: China, India.