Amblyseius lentiginosus, Denmark & Schicha, 1974

MA, MIN, ZHANG, KESHI, FAN, QING-HAI & ZHANG, ZHI-QIANG, 2024, Description of ontogenetic changes in the morphology of Amblyseius herbicolus (Chant, 1959) and Amblyseius lentiginosus Denmark & amp; Schicha, 1974 (Acari: Phytoseiidae), Zootaxa 5485 (1), pp. 7-37 : 17-31

Amblyseius lentiginosus ­Denmark­&­Schicha,­1974

(Figs 11–21)

Larva (n = 5, Figs 11, 12A, 13A, 14; Tables 4 and 5)

Dorsal idiosoma (Fig. 11A). Podonotal shield 122 (117–126) long, 111 (108–113) wide, weakly sclerotised (Fig. 11A), bearing nine pairs of setae (j1, j3, j4, j5, j6, z2, z4, z5 and s4), all smooth; s4 longest, s4> j1> j3>j6, others shorter, j1: j3 = 1.03–1.14, s4: j1 = 2.14–2.71, j3: j6 = 1.84–2.32; four pairs of lyrifissures (id2, id4, id5 and id6), id4 on membrane. Opisthonotal region weakly sclerotised and bearing five pairs of smooth setae (J5, S2, Z1, Z4 and Z5) (J5 and Z5 on ventral side), and three pairs of visible lyrifissures (idl3, idm4 and idm6), a pair of solenostomes gd8 (see Fig. 11A, B, idm6 situated on ventral side) close to J5; S2 and Z1 nub-like setae, Z4 apically blunt and longer than other dorsal setae. Refer to Table 4 for setal lengths.

Note: L: Larva; PN: Protonymph; DN: Deutonymph females; A: Adult females.

FIGURE­8. Amblyseius herbicolus , deutonymph female. A—leg I; B—leg II; C—leg III; D—leg IV.

Ventral idiosoma (Fig. 11B) smooth, without discernible shields; stigmata and peritremes absent. Coxisternal area (Fig. 11B) with three pairs of setae st1, st2 and st3, st2–st2 36 (34–38); four pairs of opisthogastric setae (JV1, JV2, JV5 and ZV2) present, JV2 longest, JV2> JV1> ZV2, JV2: ZV2 = 2.00–2.79, JV5 setal nubs; a pair of paranal (Pa) and a postanal seta (Pst) present around anal valve, Pa longer than Pst, Pa: Pst = 1.64 –2.05; a pair of round solenostomes gv3 posteromedial to JV2, distance gv3–gv3 15 (14–16).

Gnathosoma Chelicera (Fig. 11C) with movable digit 16 (14–18) long, bearing a tooth, fixed digit 17 (15–20) long, bearing 6 teeth, pilus dentilis closed to fourth teeth from tip of chelicera. Palptrochanter (Fig. 12A) without setae; femur with a spatulate (al), three simple setae and ten small denticles near seta d2; genu bearing a spatulate (al1) and four simple setae; tarsal apotele two-tined. Hypostome (Fig. 13A) with two pairs of hypostomal setae (h1 and h2); deutosternal groove present but weakly developed, without rows of denticles.

Legs (Fig. 14, Table 5). Leg I 261 (251–271) long, setal formula (coxa to basitarsus): 2, 4, 10, 8, 8, 1. A smooth and blunt-tipped macroseta on genu I 35 (33–40) in length. Leg II 229 (213–236) long, setal formula: 2, 4, 7, 6, 7, 4. A smooth and blunt-tipped macroseta on genu II 44 (43–45) in length. Leg III 333 (208–232) long, setal formula: 2, 4, 5, 6, 7, 4. A smooth and blunt-tipped macroseta on genu and tibia, respectively, 71 (67–78), 57 (53–66) in length.

FIGURE­9.­ Amblyseius herbicolus , adult female. A— dorsal idiosoma; B—ventral idiosoma; C—chelicera; D—spermathecal apparatus.

FIGURE­10. Amblyseius herbicolus , adult female. A—leg I; B—leg II; C—leg III; D—leg IV.

Protonymph (n = 10, Figs 12B, 13B, 15, 16, Tables 4, 5).

Dorsal idiosoma (Fig. 15A). Dorsum with well separated podonotal and opisthonotal shields, both smooth and weakly sclerotised; podonotal shield 119 (109–125) long, 113 (105–121) wide, with nine pairs of smooth setae (j1, j3, j4, j5, j6, s4, z2, z4 and z5), five pairs of lyrifissures (id2, id3, id4, id5 and id6); j1, j3 and s4 longer than other setae and ratios j1: j3 = 0.64–0.77, s4: j1 = 2.16–2.73, j3: j6 = 4.23–6.98. Setae J2, r3 and R1, and lyrifissures id2 and id3 present on interscutal membrane, with three pairs of smooth setae (J2, S2 and Z1), four pairs of lyrifissures (idl2, idl3, idl4 and idm2) and a pair of solenostomes gd6. Opisthonotal shield with five pairs of setae (J5, S4, S5, Z4 and Z5) and four pairs of lyrifissures (idl4, idm5, idm6 and idx) and two pairs of solenostomes (gd8 and gd9), all setae smooth and short, Z4 and Z5 weakly serrate, blunt-tipped, and obviously longer than others, Z4 longer than Z5, Z5: Z4 = 0.58–0.74. Peritreme present and extending to level between s4 and z5.

Ventral idiosoma (Fig. 15B). Coxisternal area with three pairs of setae (st1, st2 and st3) and two pairs of discernible lyrifissures (iv1 and iv2), st2–st2 55 (52–60); four pairs of opisthogastric setae (JV1, JV2, JV5 and ZV2) present on membranous around anal shield, ZV2–ZV2 53 (39–61), a pair of paranal setae (Pa) and a postanal seta (Pst) becoming shorter than that of larva around anal valve, Pa: Pst = 0.76–1.14; unsclerotised opisthogastric cuticle with four pairs of setae (JV1, JV2, JV5 and ZV2), a pair of circular solenostomes gv3 posteromedial to JV2, distance gv3–gv3 16 (14–19), and with two pairs of lyrifissures (ivo and ivp).

FIGURE­11. Amblyseius lentiginosus , larva. A— dorsal idiosoma; B—ventral idiosoma; C—chelicera.

Gnathosoma. Chelicera (Fig. 15C) with movable digit 20 (18–22) long, bearing two teeth, fixed digit 22 (20– 24) long, bearing six teeth, pilus dentilis located between fourth and fifth tooth from tip of chelicera, 6 long. Palptrochanter (Fig. 12B) with one seta; femur with a spatulate seta (al) and three simple setae; genu bearing a spatulate (al1) and four simple setae; tarsal apotele two-tined. Hypostome (Fig. 13B) with three pairs of hypostomal setae (h1, h2 and h3) and a pair of palpcoxal setae (pc); deutosternal groove with seven rows of denticles, each row bearing two marginal denticles, three small denticles near base of second row of teeth in deutosternal groove.

Legs (Fig. 16, Table 5). Leg I 282 (262–298) long, setal formula (coxa to basitarsus): 2, 4, 10, 8, 8, 1. Macroseta on genu 30 (26–33) in length. Leg II 233 (212–249) long, setal formula: 2, 4, 7, 6, 7, 4. A blunt-tipped macroseta on genu, 33 (27–38) in length. Leg III 232 (210–251) long, setal formula: 2, 4, 5, 6, 7, 4. Blunt-tipped macroseta on genu 56 (48–63), tibia 45 (39–59) in length. Leg IV 280 (254–299) long, setal formula: 1, 4, 4, 5, 6, 4 (including three macrosetae). Blunt-tipped macroseta on genu 90 (76–110), tibia 85 (74–109), basitarsus 83 (70–94) in length.

Deutonymph­female (n = 10, Figs 12C, 13C, 17A, B, 18, Tables 4 and 5).

FIGURE­12. Amblyseius lentiginosus , palps. A—larva; B—protonymph; C—deutonymph female; D—adult female.

Dorsal idiosoma (Fig. 17A). Dorsal shield 177 (160–185) long, 86 (80–91) wide, oval, smooth; with 17 pairs of setae, all smooth, but Z4 and Z5 weakly serrate; j1, j3, s4, Z4 and Z5 longer than other setae, Z5 longer than Z4, ratios j1: j3 = 0.57–0.72, s4: j1 = 2.26–2.73, j3: j6 = 7.44–10.47, Z5: Z4 = 1.10–1.41; six pairs of solenostomes (gd1, gd2, gd5, gd6, gd8 and gd9) and thirteen pairs of lyrifissures (id1, id2, id3, id4, id5, id6, idl3, idl4, idm2, idm3, idm5, idm6 and is1). Setae r3, R1 smooth and two pairs of lyrifissures id2 and id3 on unsclerotised membrane. Peritremes extending to level between j3 and z2.

Ventral idiosoma (Fig 17B). Sternogenital shield faint, with five pairs of setae (st1, st2, st3, st4 and st5) and four pairs of lyrifissures (iv1, iv2, iv3 and iv5), st2–st2 64 (59–92). Unsclerotised opisthogastric cuticle with seven pairs of setae, JV1, JV2, JV4, JV5, ZV1, ZV2 and ZV3, and five pairs of lyrifissures ivo, and a pair of ivp around anal shield, a pair of solenostomes gv3 posteromedial to JV2; distance gv3–gv3 17 (15–22).

Gnathosoma Chelicera (Fig. 17D) with movable digit 25 (22–27) long, bearing two teeth, fixed digit 27 (24– 31) long, bearing eight teeth, pilus dentilis located between fourth and fifth tooth from tip of chelicera, 8 long. Palptrochanter (Fig. 12C) with two setae; femur with a spatulate seta (al) and four simple setae; genu bearing two spatulate (al1 and al2) and five simple setae; tarsal apotele two-pronged. Hypostome (Fig. 13C) with three pairs of hypostomal setae (h1, h2 and h3) and a pair of palpcoxal setae (pc). Deutosternal groove 5 wide, with eight rows of denticles, each row bearing two denticles.

FIGURE­13. Amblyseius lentiginosus , hypostomes. A—larva; B—protonymph; C— deutonymph female; D—adult female.

Legs (Fig. 18, Table 5). Leg I 332 (324–346) long, setal formula (coxa to basitarsus): 2, 5, 12, 10, 10, 1; with a smooth macroseta on genu 33 (29–42). Leg II 269 (253–296) long, setal formula: 2, 5, 10, 7, 7, 4; with a smooth and slightly blunt-tipped macroseta on genu 35 (32–38). Leg III 274 (262–289) long, setal formula: 2, 5, 6, 7, 7, 4; with a smooth and blunt-tipped macroseta on each of genu 59 (51–64), tibia 48 (43–52). Leg IV 342 (323–376) long, setal formula: 1, 5, 6, 7, 6, 4, with a smooth and blunt-tipped macroseta on genu 102 (89–115), tibia 86 (70–97), and basitarsus 73 (64–80).

Deutonymph­male (n = 3, Fig. 17C).

Dorsal shield, sternal shield, and genital shield consistent with those of deutonymphal females, but opisthogastric cuticle with four pairs of setae (JV1, JV2, JV5 and ZV2), a pair of solenostomes gv3 posteromedial to JV2, and without lyrifissure.

Adult­female (n = 12, Figs 12D, 13D, 19, 20, Tables 4 and 5).

Idiosoma. Setal pattern 10A:9B/JV-3:ZV.

FIGURE­14. Amblyseius lentiginosus , larva. A—leg I; B—leg II; C—leg III.

Dorsal idiosoma (Fig. 19A). Dorsal shield smooth, with a waist at level of R1, 341 (324–354) long, 176 (166– 185) wide; 17 pairs of dorsal setae, all smooth but Z4 and Z5 weakly serrate, Z5 slightly blunt-tipped; j1, j3, s4, Z4 and Z5 longer than others, Z5> Z4> s4> j3> j1, Z5 longest, ratios j1: j3 = 0.54–0.69, s4: j1 = 2.67–3.06, j3: j6 = 7.59–10.87, Z5: Z4 = 1.50–1.71; with seven pairs of solenostomes (gd1, gd2, gd4, gd5, gd6, gd8 and gd9) and 14 pairs of lyrifissures (id1, id2, id3, id4, id5, idl2, idl3, idl4, idm2, idm3, idm5, idm6, idx and is1), id3 on peritrematic plate. Setae r3 and R1 smooth, on unsclerotised membrane. Peritremes extending close to j1 level.

Ventral idiosoma (Fig. 19B). Sternal shield smooth, 62 (60–64) long, 69 (66–72) wide, length: width = 0.84– 0.93, anterior edge convex, posterior margin straight; with three pairs of setae (st1, st2 and st3) and lyrifissures (iv1 and iv2), iv1 closed to st1, iv2 anterior to st3; st4 and iv3 on metasternal platelets. Genital shield smooth, 120 (115–125) long, 78 (75–83) wide, a pair of lyrifissures of iv5 close to st5 and on membrane. A transverse sclerite present between genital and ventrianal shields. Ventrianal shield smooth, approximately pentagonal, with a waist at ZV3 level, 111 (101–121) long, 82 (76–88) wide; three pairs of preanal setae (JV1, JV2 and ZV2), JV1 close to anterior margin of ventrianal shield, ZV2 close to lateral margin; a pair of conspicuous elliptical solenostomes (gv3) posteromedial to JV2; distance gv3–gv3 17 (15–22); a pair of preanal setae (Pa) and a postanal seta (Pst) present surround anus, Pa: Pst = 0.80–1.46. Four pairs of setae (JV4, JV5, ZV1 and ZV3) and four pairs of lyrifissures present on soft cuticle surrounding ventrianal shield. Primary metapodal platelet 25 (22–28) long, 6 (5–7) wide; secondary platelet 13 (9–14) long, 3 (2–4) wide.

FIGURE­15. Amblyseius lentiginosus , protonymph. A—dorsal idiosoma; B—ventral idiosoma; C—chelicera.

Spermatheca (Fig. 19C). Calyx of spermathecal apparatus cylindrical, cervix thick, 21 (19–23) long, 7 (6–8) wide; major duct directly attached to base of calyx.

Gnathosoma. Chelicera (Fig. 19D) with movable digit 33 (30–36) long, bearing three teeth, fixed digit 35 (32–38) long, bearing ten teeth, pilus dentilis located between the fourth and fifth tooth from tip of chelicera, 9 long. Palptrochanter (Figure 12D) with two setae; femur with a spatulate (al) and four simple setae; genu bearing two spatulate (al1 and al2) and four simple setae; tarsal apotele two-tined. Hypostome (Fig. 13D) with three pairs of hypostomal setae (h1, h2 and h3) and one pair of palpcoxal setae (pc); no seta added after protonymph; deutosternal groove with eight rows of denticles, each row bearing two denticles.

FIGURE­16. Amblyseius lentiginosus , protonymph. A—leg I; B—leg II; C—leg III; D—leg IV.

Legs (Fig. 20, Table 5). Leg I 382 (326–408) long, setal formula (coxa to basitarsus): 2, 5, 12, 10, 10, 1. Macroseta on genu 37 (35–41). Leg II 324 (302–340) long, setal formula: 2, 5, 10, 7, 7, 4. Macroseta on genu 38 (36–40) in length. Leg III 333 (307–415) long, setal formula: 2, 5, 6, 7, 7, 4. Macroseta on genu 56 (51–61), tibia 48 (46–52), respectively. Leg IV 418 (395–432) long, setal formula: 1, 5, 6, 7, 6, 4. A blunt-tipped macroseta on genu 115 (104–128), tibia 88 (77–92), basitarsus 74 (71–78).

Adult­male (n = 8, Fig. 21).

Dorsal idiosoma (Fig. 21A). Dorsal shield smooth, 258 (246–273) long, 144 (138–154) wide; with 19 pairs of setae (r3 and R1 smooth and on dorsal shield), all smooth but Z4 and Z5 weakly serrate, Z5 blunt-tipped, j1: j3 = 0.49–0.72, j3: j6 = 7.41–9.39, s4: j1 = 2.45–3.68; Z5: Z4 = 1.53–1.64. Dorsal shield with four pairs of visible solenostomes (gd2, gd4, gd8 and gd9) and 14 pairs of lyrifissures (id1, id2, id3, id4, id5, idl2, idl3, idl4, idm2, idm3, idm4, idm5, idm6, and is1). Peritremes extending to j1 level.

Ventral idiosoma (Fig. 21B). Sternogenital shield smooth, 125 (120–132) long, 57 (54–58) wide; anterior margin lightly convex, posterior margin nearly straight, bearing five pairs of attenuate setae (st1, st2, st3, st4 and st5) and three pairs of lyrifissures iv1, iv2 and iv3. Ventrianal shield subtriangular, anteromedian extending forward, with several striae anterior to JV1, 112 (106–120) long, 154 (144–164) wide, with three pairs of preanal setae (JV1, JV2 and ZV2) and two pairs of lyrifissures ivo, and a pair of elliptic solenostomes gv3 posteromedial to JV2, distance gv3–gv3 15 (12–20). Seta JV5 on soft cuticle surrounding ventrianal shield. Lengths of setae: JV1 12 (10–15), JV2 12 (10–13), JV5 46 (44–48), ZV2 11 (10–13).

FIGURE­17. Amblyseius lentiginosus , deutonymph. A—dorsal idiosoma (female); B—ventral idiosoma (female); C—ventral idiosoma (male); D—chelicera (female).

FIGURE­18. Amblyseius lentiginosus , deutonymph female. A—leg I; B—leg II; C—leg III; D—leg IV.

Gnathosoma (Fig. 21C). Movable digit 22 (20–24) long, bearing one tooth; fixed digit 23 (22–24) long, bearing 7–8 teeth; spermatodactyl L-shaped, thorn-like projecting heel, straight foot with rounded tip. Palp and hypostome with same chaetotaxy as adult female.

Legs. Leg chaetotaxy same as adult female.

Specimens­examined:­ Laboratory-reared from specimens originated in South Canterbury: 5 larvae, 8.i.2024 ; 7 protonymphs, 12.ii.2023; 3 protonymphs, 3.ii.2024; 8 deutonymph females, 12.xii.2023; 2 deutonymph females, 3.ii.2024; 1 deutonymph male, 12.xii.2023; 2 male deutonymph males, 4.iii.2024; 12 adult females, 8.iii.2024; 8 adult males, 8.iii.2024; prepared by Keshi Zhang.