Amblyseius herbicolus

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 : 8-17

Amblyseius herbicolus ­Chant,­1959

(Figs 1–10)

Larva (n = 5, Figs 1, 2A, 3A, 4, Tables 2 and 3)

Dorsal idiosoma (Figs 1A, 1B). Podonotal shield 125 (114–129) long, 106 (104–109) wide, weakly sclerotised (Fig. 1A), 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 = 0.73–1.08, j3: j6 = 2.54–2.91, s4: j1 = 2.45–3.31; no lyrifissure or solenostome discernible. Opisthonotal region plain and bearing four pairs of smooth setae (J5, Z1, Z4 and Z5) (J5 and Z5 on ventral side) (Fig. 1B), and one pairs of visible lyrifissures (idl3) anterolateral to Z4; Z4 apically blunt and longer than other dorsal setae. Refer to Table 2 for setal lengths.

Ventral idiosoma (Fig. 1B) smooth, without discernible shield; stigmata and peritremes absent. Coxisternal area (Fig. 1B) with three pairs of setae st1, st2 and st3, st2–st2 59 (57–60); four pairs of opisthogastric setae (JV1, JV2, JV5 and ZV2) present, JV2 longer than others, JV2> ZV2> JV1, JV2: ZV2 = 1.90–3.99; a pair of paranal setae (Pa) and a postanal seta (Pst) present around anal valve, Pa: Pst = 1.93 –2.45; a pairs of round solenostomes gv3 posterior to JV2, distance gv3–gv3 13 (10–17).

FIGURE­1. Amblyseius herbicolus , larva. A—dorsal idiosoma; B—ventral idiosoma; C—chelicera.

Gnathosoma. Chelicera (Fig. 1C) with movable digit 20 (19–21) long, bearing two teeth, fixed digit 23 (22–28) long, bearing seven teeth. Palptrochanter (Fig. 2A) 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. 3A ) with two pairs of hypostomal setae (h1 and h2); deutosternal groove undiscernible, without rows of denticles.

Legs (Fig. 4, Table 3). Leg I 291 (256–319) long, setal formula (coxa to basitarsus): 2, 4, 10, 8, 8, 1. A smooth and blunt-tipped macroseta on genu I 38 (32–45) in length. Leg II 243 (234–249) long, setal formula: 2, 4, 7, 6, 7, 4. A smooth and blunt-tipped macroseta on genu II 47 (42–50) in length. Leg III 247 (242–254) long, setal formula: 2, 4, 5, 6, 7, 4. A smooth and blunt-tipped macroseta on genu or tibia, 72 (65–77) and 54 (49–61) in length, respectively.

Protonymph (n = 5, Figs 2B, 3B, 5, 6, Tables 2, 3). ­

FIGURE­2. Amblyseius herbicolus , palps. A—larva; B—protonymph; C—deutonymph female; D—adult female.

Dorsal idiosoma (Fig. 5A). Dorsum smooth and weakly sclerotised; 134 (129–148) long from j1 to j6, 267 (244–288) long from j1 to J5, 131 (123–144) wide between s4 and s4, with nine pairs of smooth setae (j1, j3, j4, j5, j6, s4, z2, z4 and z5), a pairs of lyrifissures (id5); j1, j3 and s4 longer than other setae; ratios j1: j3 = 0.73–1.08, s4: j1 = 2.45–3.31, j3: j6 = 2.54–2.91. Setae J2, S2, r3 and R1 present on interscutal membrane. Opisthonotal shield with five pairs of setae (J5, S4, S5, Z4 and Z5), J5 and S4 smooth and short, Z4 and Z5 weakly serrate and obviously longer than others, Z4 longer than Z5, Z5: Z4 = 0.47–0.55; four pairs of lyrifissures (idl3, idl4, idm5 and idm6). Peritremes present and extending to level between j6 and z5.

Ventral idiosoma (Fig. 5B). Coxisternal area with three pairs of setae (st1, st2 and st3) and a pairs of lyrifissures iv1 present, st2–st2 59 (57–60); Four pairs of opisthogastric setae (JV1, JV2, JV5 and ZV2) present anterior to anal shield, ZV2–ZV2 41 (36–44), JV2 shorter than JV1, JV2: ZV2 = 1.15–1.60; a pair of paranal setae (Pa) and a postanal seta (Pst) around anal, Pa: Pst = 1.02–1.66; a pair of circular solenostomes gv3 posterior to JV2, distance gv3–gv3 13 (10–15).

Gnathosoma Chelicera (Fig. 5C) with movable digit 23 (23–27) long, bearing three teeth, fixed digit 25 (23– 27) long, bearing nine teeth, pilus dentilis located between fourth and sixth tooth from tip of chelicera, 7 (7–8). Palptrochanter (Fig. 2B) 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. 3B ) with three pairs of hypostomal setae (h1, h2 and h3) and a pair of palpcoxal setae (pc); deutosternal groove with six rows of denticles, each row bearing two marginal denticles.

Legs (Fig. 6, Table 3). Leg I 348 (343–356) long, setal formula (coxa to basitarsus): 2, 4, 10, 8, 8, 1. Macroseta on genu 39 (34–51) in length. Leg II 275 (265–283) long, setal formula: 2, 4, 7, 6, 7, 4. A blunt-tipped macroseta on genu, 40 (37–42) in length. Leg III 275 (264–285) long, setal formula: 2, 4, 5, 6, 7, 4. Blunt-tipped macroseta on genu 57 (52–65), and tibia 42 (39–48) in length. Leg IV 344 (328–352) long, setal formula: 1, 4, 4, 5, 6, 4 (including three macrosetae), blunt-tipped macroseta on genu 98 (90–103), tibia 119 (115–123), basitarsus 99 (93–103) in length.

Deutonymph­female (n = 4, Figs 2C, 3C, 7, 8, Tables 2 and 3)

FIGURE­4. Amblyseius herbicolus , lava. A—leg I; B—leg II; C—leg III.

Dorsal idiosoma (Fig. 7A). Dorsal shield 285 (279–290) long, 140 (136–147) 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, Z4 longer than Z5, ratios j1: j3 = 0.70–0.82, s4: j1 = 2.54–2.92, j3: j6 = 5.61–8.00, Z5: Z4 = 0.41–0.81; seven pairs of solenostomes (gd1, gd2, gd4, gd5, gd6, gd8 and gd9) and seven pairs of lyrifissures (id1, id5, idl2, idl3, idl4, idm5 and idm6). Setae r3, R1 smooth on unsclerotised membrane. Peritreme extending close to j3 level.

Ventral idiosoma (Fig. 7B). Sternogenital area faint, 73 (72–73) from st1 to st5, st2–st2 61 (46–70), with five pairs of setae, st1, st2, st3, st4 and st5. Unsclerotised opisthogastric cuticle with seven pairs of setae, JV1, JV2, JV4, JV5, ZV1, ZV2 and ZV3, ZV2–ZV2 54 (47–63), JV2: ZV2 = 1.00–1.26, solenostome gv3 posterior to JV2; distance gv3–gv3 20 (18–21), Pa: Pst = 0.97–1.16.

Gnathosoma. Chelicera (Fig. 7C) with movable digit 26 (25–27) long, bearing three teeth, fixed digit 27 (26– 29) long, bearing nine teeth, pilus dentilis located near seventh tooth from tip of chelicera. Palptrochanter (Fig. 2C) 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-tined. Hypostome ( Fig. 3C ) 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 denticles.

Legs (Fig. 8, Table 3). Leg I 405 (389–422) long, setal formula (coxa to basitarsus): 2, 5, 12, 10, 10, 2; with a smooth macroseta on genu, 40 (38–42). Leg II 327 (329–334) long, setal formula: 2, 5, 10, 7, 7, 4; with a smooth and blunt-tipped macroseta on genu, 39 (31–45). Leg III 334 (327–339) long, setal formula: 2, 5, 6, 7, 7, 4; with a smooth and blunt-tipped macroseta on genu, 56 (52–59), tibia 43 (39–47). Leg IV 419 (401–431) long, setal formula: 1, 5, 6, 7, 6, 4, with a smooth and blunt-tipped macroseta on each of genu, 118 (111–121), tibia 83 (69–88), and basitarsus 73 (68–77).

Deutonymph­male: none.

Adult­female (n = 5, Figs 2D, 3D, 9, 10, Tables 2 and 3).

Idiosoma. Setal pattern 10A:9BJV-3:ZV.

Dorsal idiosoma (Fig. 9A). Dorsal shield smooth, with a waist at level of R1, 361 (352–370) long, 206 (197– 214) wide; a pair of muscle marks (sigilla) present between j3, four pairs of muscles marks present between j6 and Z4; 17 pairs of dorsal setae, all smooth except Z4 and Z5 (weakly serrate); j1, j3, s4, Z4 and Z5 longer than others, Z5> Z4> s4> j3> j1, Z5 longest, ratios j1: j3 = 0.82–1.02, s4: j1 = 2.24–2.83, j3: j6 = 4.70–7.12, Z5: Z4 = 2.40–2.67; without solenostomes and lyrifissures added. Setae r3 and R1 smooth, on unsclerotised membrane. Peritremes extending to level anterior to j1.

Ventral idiosoma (Fig. 9B). Sternal shield smooth, 75 (72–79) long, 74 (71–77) wide, length: width = 0.96– 1.11, 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, 113 (110– 116) long, 61 (55–68) wide, a pair of lyrifissures of iv5 close to st5 and on membrane. Ventrianal shield smooth, approximately vase-shaped, with a strong waist at JV2 level, 118 (116–120) long, 47 (35–52) wide; three pairs of preanal setae (JV1, JV2 and ZV2), JV1 close to anterior margin of ventrianal shield, ZV2 close to lateral margin, JV2: ZV2 = 1.11–1.35; a pair of solenostomes gv3 posterior to JV2; distance gv3–gv3 26 (24–29); preanal setae (Pa) and postanal seta (Pst) present surround anus, Pa: Pst = 0.94–1.13. Primary metapodal platelet 22 (20–24) long, 6 (5–7) wide; secondary platelet 18 (14–20) long, 3 (2–3) wide.

FIGURE­5.­ Amblyseius herbicolus , protonymph. A— dorsal idiosoma; B—ventral idiosoma; C—chelicera.

FIGURE­6. Amblyseius herbicolus , protonymph. A—leg I; B—leg II; C—leg III; D—leg IV.

Spermatheca (Fig. 9D). Calyx of spermathecal apparatus long, tubular, arms of calyx flaring distally, atrium large, bifurcate at junction with major duct, arms of calyx 26 (18–33) long, 8 (5–10) wide.

Gnathosoma Chelicera (Fig. 9C) with movable digit 34 (32–36) long, bearing four teeth, fixed digit 34 (31–35) long, bearing 13 teeth, pilus dentilis located between the sixth tooth from tip of chelicera, 12 (9–14) in length. Palptrochanter (Fig. 2D) 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. 3D ) 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, first row bearing four denticles, other rows each bearing two denticles.

Legs (Fig. 10, Table 3). Leg I 472 (463–485) long, setal formula (coxa to basitarsus): 2, 5, 12, 10, 10, 2. Macroseta on genu 48 (43–59) in length. Leg II 373 (349–397) long, setal formula: 2, 5, 10, 7, 7, 4. Macroseta on genu 41 (35–45) in length. Leg III 381 (356–405) long, setal formula: 2, 5, 6, 7, 7, 4. Macroseta on genu 50 (38–60), tibia 40 (35–43) in length, respectively. ­ Leg IV 484 (447–513) long, setal formula: 1, 5, 6, 7, 6, 4. A blunt-tipped macroseta on genu 116 (105–121), tibia 80 (69–88), basitarsus 73 (68–77) in length.

Adult­male: none.

Specimens­examined.­ Laboratory-reared from specimens originated in Auckland: 5 larvae, 5 protonymphs, 4 deutonymphs, 5 adult females, 8.iii.2024, prepared by Keshi Zhang .

FIGURE­7. Amblyseius herbicolus , deutonymph female. A—dorsal idiosoma; B—ventral idiosoma; C—chelicera.

Figures

FIGURE­3. Amblyseius herbicolus, hypostomes. A—larva; B—protonymph; C—deutonymph female; D—adult female.