Ontogenetic changes in the morphology of Neoseiulus barkeri (Acari Phytoseiidae) Author Ma, Min College of Plant Protection, Shanxi Agriculture University, Taigu, China. Author Zhang, Bin Basic Courses Department, Shanxi Agriculture University, Taigu, China. Author Fan, Qing-Hai Plant Health & Environment Laboratory, Ministry for Primary Industries, Auckland, New Zealand. Author Zhang, Zhi-Qiang Manaaki-Whenua-Landcare Research, Private Bag 92170, Auckland, New Zealand & School of Biological Sciences, The University of Auckland, Auckland, New Zealand. text Zootaxa 2020 2020-12-31 4900 1 5 19 journal article 9040 10.11646/zootaxa.4900.1.4 f8365c16-4cea-4ef4-b0e0-67131847f714 1175-5326 4408849 1EE5C33E-E69C-43B1-950E-0119CD43771E Neoseiulus barkeri Hughes Neoseiulus barkeri Hughes, 1948: 141 . LARVA (n=9, Figures 1 , 2 , 11A , 12A , Table 1 ) TABLE 1. Comparison of leg chaetotaxy in Neoseiulus barkeri of different developmental stages.

Leg	Coxae	Trochanters	Femora	Genua	Tibiae	Basitarsi
L	0-0/1-0/1-0	1-0/1-0/1-1	2-2/1-2/1-2	1-2/1-2/1-1	1-2/1-2/1-1	0-1/0-0/0-0
Leg I	PN	0-0/1-0/1-0	1-0/1-0/1-1	2-2/1-2/1-2	1-2/1-2/1-1	1-2/1-2/1-1	0-1/0-0/0-0
DN	0-0/1-0/1-0	1-0/1-0/ 2 -1	2- 3 / 2 -2/ 2 -1	2 -2/1-2/1- 2	2 -2/1-2/1- 2	0-1/0- 1 /0-0
A	0-0/1-0/1-0	1-0/1-0/2-1	2-3/2-2/2-1	2-2/1-2/1-2	2-2/1-2/1-2	0-1/0-1/0-0
L	0-0/1-0/1-0	1-0/1-0/1-1	1-2/1-2/0-1	1-2/0-2/0-1	1-1/1-2/1-1	1-1/0-1/0-1
Leg II	PN DN	0-0/1-0/1-0 0-0/1-0/1-0	1-0/1-0/1-1 1-0/1- 1 /1-1	1-2/1-2/0-1 2-3 /1-2/ 1 -1	1-2/0-2/0-1 2 -2/0-2/0-1	1-1/1-2/1-1 1-1/1-2/1-1	1-1/0-1/0-1 1-1/0-1/0-1
A	0-0/1-0/1-0	1-0/1-1/1-1	2-3/1-2/1-1	2-2/0-2/0-1	1-1/1-2/1-1	1-1/0-1/0-1
L	0-0/1-0/1-0	1-1/0-0/1-1	1-2/1-1/0-0	1-2/0-2/0-1	1-1/1-2/1-1	1-1/0-1/0-1
Leg III	PN DN	0-0/1-0/1-0 0-0/1-0/1-0	1-1/0-0/1-1 1-1/ 1 -0/1-1	1-2/1-1/0-0 1-2/1-1/0- 1	1-2/0-2/0-1 1-2/ 1 -2/0-1	1-1/1-2/1-1 1-1/1-2/1-1`	1-1/0-1/0-1 1-1/0-1/0-1
A	0-0/1-0/1-0	1-1/1-0/1-1	1-2/1-1/0-1	1-2/1-2/0-1	1-1/1-2/1-1	1-1/0-1/0-1
L	N/A	N/A	N/A	N/A	N/A	N/A
Leg IV	PN DN	0-0/1-0/0-0 0-0/1-0/0-0	0-1/1-1/1-0 1 -1/1-1/1-0	0-2/1-1/0-0 1 -2/1-1/0- 1	0-2/1-2/0-0 1 -2/1-2/0- 1	1-1/1-2/0-1 1-1/1-2/0-1	1-1/0-1/0-1 1-1/0-1/0-1
A	0-0/1-0/0-0	1-1/1-1/1-0	1-2/1-1/0-1	1-2/1-2/0-1	1-1/1-2/0-1	1-1/0-1/0-1

L: larva; PN: protonymph; DN: deutonymph; A: adult; numbers in bold: addition of setae on leg segments. Idiosoma ( Figures 1A & B , Table 1 ) 188 (162–211) long, 122 (115–127) wide. DORSUM ( Figure 1A ): podonotal shield weakly sclerotized ( Figure 1A ), smooth, bearing nine pairs of setae ( j1 , j3 , j4 , j5 , j6 , s4 , z2 , z4 and z5 ), all smooth, s4 longest, reaching base of z4 ; s4 > j1 > j3 , j1 as long as j6 and other podonotal setae shorter. Opisthonotal region bearing four pairs of smooth setae J5 , Z1 , Z4 and Z5 ; Z4 apically blunt and conspicuously longer than other dorsal setae. Without discernible lyrifissures and solenostomes. Lengths of setae: j1 20 (15–22), j3 15 (13–17), j4 8 (7–9), j5 8 (8–10), j6 20 (15–23), z2 8 (6–10), z4 8 (7–10), z5 7 (6–8), s4 33 (32–36), J5 4 (3–4), Z1 4 (4–6), Z4 73 (63–82), Z5 4 (3–5). VENTRUM ( Figure 1B ): smooth, without discernible shields. Coxisternal area ( Figure 1B ) bearing three pairs of setae st1 , st2 and st3 , without discernible lyrifissures or solenostomes. Four pairs of opisthogastric setae, JV1 , JV2 , JV5 and ZV2 present on membranous cuticles anterior to or around anal valve, JV2 nearly twice as long as JV5 , ZV2 as long as JV5 ; a pair of paranal setae ( pa ) and a postanal seta ( po ) present around anal valve, pa longer than po ; a pair of circular solenostomes ( gv3 ) posteromedian to JV2 , distance gv3–gv3 9 (7–12). Lengths of setae: st1 15 (12–17), st2 13 (12–15), st3 12 (9–14), JV1 8 (7–9), JV2 13 (10–16), JV5 4 (3–5), ZV2 5 (4–7). FIGURE 1. Neoseiulus barkeri (larva). A. dorsal idiosoma; B. ventral idiosoma; C & D. variations of chelicera. Gnathosoma . CHELICERA ( Figures 1C & D ): movable digit 16 (14–17) long, bearing a tooth; fixed digit 16 (15–18) long, with two teeth and only with a tiny pilus dentilis near second tooth. PALP ( Figure 11A ): trochanter devoid of setae; femur with a strong and columnar seta and three simple setae; genu bearing a spatulate and four simple setae; tibia with simple setae; division between tibia and tarsus undiscernible; tarsal apotele 2-tined. HYPO- STOME ( Figure 12A ): weakly sclerotized with only two pairs of hypostomal setae ( h1 and h2 ) and a row of tiny denticles; deutosternal groove faint. Legs ( Figure 2 ). Leg I 236 (227–250) long, number of setae (coxa to basitarsus): 2, 4, 10, 8, 8, 1. Leg II 183 (169–194) long, number of setae: 2, 4, 7, 6, 7, 4. Leg III 180 (171–193) long, number of setae: 2, 4, 5, 6, 7, 4. All legs without macrosetae. PROTONYMPH (n=10, Figures 3 , 4 , 11B , 12B , Table 1 ) Idiosoma ( Figure 3A , Table 1 ) Podonotal shield 246 (220–272) long, 124 (117–129) wide at level of s4 , smooth, weakly sclerotized, with nine pairs of setae and a pair of solenostomes ( gd1 ) and lyrifissures ( id1 ); podonotal and opisthonotal shields separated by interscutal membrane, which bears three pairs of setae ( J2 , S2 , and Z1 ), four pairs of lyrifissures ( id6 , idl2 , idm3 and is1 ), two pairs of sclerites (one pair big and another pair small); r3 and R1 present on soft cuticle. Opisthonotal shield sub-rectangle, 59 (53–65) long, 70 (50–76) wide at level of S4 , with five pairs of setae ( S4 , S5 , J5 , Z4 and Z5 ) and a pair of lyrifissures ( idl4 ) and solenostomes ( gd9 ), Z4 and Z5 barbed and longer than other setae; Z4 longer than distance its base and that of seta Z5 ; Marginal setae r3 smooth and as long as R1 . Lengths of setae: j1 15 (14–17), j3 16 (13–17), j4 12 (10–15), j5 13 (10–14), j6 14 (12–16), r3 11 (9–13), z2 15 (13–15), z4 14 (12–16), z5 12 (10–16), s4 21 (19–24), S2 14 (11–16), S4 12 (10–14), S5 10 (8–11), J2 13 (10–15), J5 9 (7–10), Z1 13 (11–17), Z4 28 (25–31), Z5 31 (28–33), R1 13 (12–15). VENTRUM ( Figure 3B ): smooth, without discernible shields. Stigmata located ventrolaterally between coxae III and IV. Peritremes extending close to level of z5 . Coxisternal area with st1 , st2 and st3 , without lyrifissures or solenostomes. Four pairs of opisthogastric setae ( JV1 , JV2 , JV5 and ZV2 ) and two pairs of lyrifissures on membranous cuticle around anal valve, JV1 , JV5 and ZV2 obviously longer than those in larva, JV5 smooth, a pair of paranal setae ( pa ) and a postanal seta ( po ) present around anal valve; solenostomes gv3 (circular) posteromedian to JV2 , distance gv3–gv3 11 (9–13). Lengths of setae: st1 17 (14–19), st2 16 (15–19), st3 16 (14–19), JV1 13 (12–16), JV2 13 (11–14), JV5 16 (12–19), ZV2 12 (10–14) . FIGURE 2. Neoseiulus barkeri (larva). A. leg I; B. leg II; C. leg III. Gnathosoma . CHELICERA ( Figure 3C ): movable digit 21 (17–24) long, bearing a tooth, fixed digit 23 (21–25) long, bearing four teeth, pilus dentilis well-developed, near forth tooth. PALP ( Figure 11B ): a seta added on trochanter; femur with a spatulate seta and three simple setae, genu with a stout seta and four simple setae; tibia with several simple setae; tarsal apotele 2-tined as in larva. HYPOSTOME ( Figure 12B ): with three pairs of hypostomal setae ( h1 , h2 and h3 ) and a pair of palpcoxal setae ( pc) ; Deutosternal groove weakly developed, with four rows of denticles. Legs ( Figure 4 ). Leg I 270 (249–287), number of setae (coxa to basitarsus): 2, 4, 10, 8, 8, 1. Without seta added. FIGURE 3. Neoseiulus barkeri (protonymph). A. dorsal idiosoma; B. ventral idiosoma; C. chelicera. Leg II 208 (195–220), number of setae (coxa to basitarsus): 2, 4, 7, 6, 7, 4. Without seta added. Leg III 200 (190–209) long; number of setae same as in larva. Leg IV 284 (261–286) long; number of setae (coxa to basitarsus): 1, 4, 4, 5, 6, 4; basitarsus with a simple macroseta 54 (51–60). DEUTONYMPH (n=9, females, 4 males , Figures 5 , 6 , 11C , 12C , Table 1 ) Idiosoma ( Figure 5A , Table 1 ) 310 (299–320) long, 142 (137–147) wide; Podonotal and opisthonotal shields fused. DORSUM: smooth, bearing 17 pairs of smooth setae, except Z4 and Z5 barbed; ten pairs of lyrifissures ( id1 , id2 , id6 , idl2, idl3 , idl4, idm3 , idm5 , idm6 and is1 ), four pairs of solenostomes ( gd1 , gd4 , gd6 and gd9 ); marginal setae r3 and R1 on interscutal membrane, R1 at level of lateral incisions. Lengths of setae: j1 18 (16–21), j3 22 (20–24), j4 15 (14–17), j5 16 (13–18), j6 17 (14–20), r3 18 (14–21), z2 19 (17–21), z4 20 (18–23), z5 17 (15–21), s4 25 (23–29), S2 23 (19–25), S4 20 (18–21), S5 19 (16–22), J2 19 (15–22), J5 12 (10–14), Z1 20 (18–24), Z4 35 (33–36), Z5 42 (39–46), R1 19 (16–21). VENTRUM ( Figures 5B & 5C ): smooth, without discernible shields. Peritremes distinct, extending close to j3 . Coxisternal area bearing five pairs of setae, st4 and st5 present; three pairs of lyrifissures ( iv1 , iv2 and iv3 ). Sexes distinguishable—female with seven pairs of smooth setae ( JV1 , JV2 , JV4 , JV5 , ZV1 , ZV2 and ZV3 ) and three pairs of lyrifissures on membrane around anal shield on ventrianal area ( Figure 5B ); male with five pairs of setae (JV1 , JV2 , JV4 , JV5 and ZV2) and with two pairs of lyrifissures on membrane of ventrianal area. A pair of paranal setae ( pa ) and a postanal seta ( po ) of subequal length present around anal valve on anal shield ( Figure 5C ). Solenostomes gv3 , circular, posteromedian to JV2 , distance gv3–gv3 14 (13–16) long. Lengths of setae: st1 24 (18–27), st2 20 (15–23), st3 19 (16–21), st4 15 (13–16), st5 16 (14–20), JV1 17 (13–20), JV2 17 (11–20), JV4 18 (12–20), JV5 29 (22–35), ZV2 13 (10–16), ZV3 9 (7–10) . Gnathosoma . CHELICERA ( Figures 5D & E ): movable digit 26 (24–28) long, bearing a tooth, fixed digit 29 (28–31) long, bearing five visible teeth. PALP ( Figure 11C ). Trochanter with two setae; one simple seta added on femur; one stout seta added on genu; tibia with several simple setae; tarsal apotele 2-tined as in protonymph. HY- POSTOME ( Figure 12C ): with three pairs of hypostomal setae ( h1 , h2 and h3 ) and a pair of palpcoxal setae ( pc) ; deutosternal groove weak, with eight rows of denticles; corniculi horn-like. FIGURE 4 . Neoseiulus barkeri (protonymph). A. leg I; B. leg II; C. leg III; D. leg IV. Legs ( Figure 6 ). Leg I 328 (318–339) long; number of setae (coxa to basitarsus): 2, 5, 12, 10, 10, 2. Trochanter added a seta, femur added two setae, genu and tibia added two setae to each segment, basitarsus added a seta. Other setae same as in protonymph. Leg II 250 (233–268) long; number of setae (coxa to basitarsus): 2, 5, 10, 7, 7, 4. A seta added on trochanter, three setae added on femur, a seta added on genu. Other setae same as in protonymph. Leg III 249 (244–258) long; number of setae (coxa to basitarsus): 2, 5, 6, 7, 7, 4. A seta added to each trochanter, femur and genu. Other setae same as in protonymph. Leg IV 320 (311–339) long; number of setae (coxa to basitarsus): 1, 5, 6, 7, 6, 4. A setae added on trochanter, two setae added on femur and genu respectively. Basitarsus with a simple macroseta 48 (43–64). FEMALE (n=10, Figures 7 , 8 , 9 , 11D , 12D , Table 1 ) FIGURE 5. Neoseiulus barkeri (deutonymph). A. dorsal idiosoma; B & C. ventral idiosoma (B: female, C: male); D & E. variations of chelicera. Idiosoma ( Figure 7A ) 368 (355–380) long, 212 (207–219) wide. DORSUM: ovoid with notch at R1 level, smooth, muscle marks between j1 and J2 , bearing 17 pairs of setae, smooth, except Z4 and Z5 barbed; five pairs of solenostomes ( gd1, gd4, gd6 , gd8 and gd9 ) and 15 pairs of lyrifissures ( id1 , id2 , id4 , id5 , id6 , idl2 , idl3, idl4 , idm1 , idm2 , idm3 , idm4 , idm5, idm6 and is1 ); dorsal setae short and smooth except Z4 , Z5 barbed and Z5 longer than other setae; Lengths of setae: j1 19 (14–21), j3 24 (22–27), j4 17 (14–20), j5 17 (12–21), j6 20 (18–22), r3 23 (19–26), z2 22 (20–24), z4 21 (16–25), z5 18 (15–20), s4 27 (25–30), S2 23 (19–25), S4 26 (23–29), S5 25 (21–29), J2 25 (23–28), J5 12 (10–14), Z1 25 (18–27), Z4 37 (34–40), Z5 54 (52–59), R1 25 (20–29). VENTRUM ( Figure 7B ): tritosternum with a stalk-like base and two flagella. Sternal shield 81 (76–85) long, 74 (70–76) wide at level of ZV2 , smooth, anterior edge convex, posterior margin concave, bearing three pairs of setae ( st1 , st2 and st3 ) and two pairs of lyrifissures ( iv1 and iv2 ); st4 and iv3 present on a pair of metasternal platelets. Peritremes extending close to j1 level. Genital shield smooth, 109 (106–120) long, 66 (64–67) wide, with three pairs of muscle marks. Paragenital lyrifissures located on soft cuticle between st5 and ZV1 . Ventrianal shield pentagon-shaped, 99 (94–106) long, 59 (57–62) wide, reticulated, anterior edge straight, with three pairs of preanal setae ( JV1 , JV2 and ZV2 ), a pair of circular solenostomes gv3 posteromediad of JV 2, distance gv3–gv3 23 (21–26). Two pairs of marginal muscle marks situated at JV5 level. JV4 , JV5 , ZV1 , ZV3 and three pairs of lyrifissures present on membranous cuticle around anal valve; a pair of paranal setae ( pa ) and a postanal seta ( po ) of subequal length present around anal valve. Lengths of setae: st1 28 (25–31), st2 22 (19–26), st3 23 (19–27), st4 26 (23–29), st5 24 (23–30), JV1 23 (19–27), JV2 21 (18–26), JV4 21 (17–25), JV5 50 (49–55), ZV1 26 (22–28), ZV2 23 (20–26), ZV3 18 (17–21). Primary metapodal platelet 35 (28–36) long, 5 (4–6) wide; secondary platelet 16 (15–18) long, 3 (2–3) wide. Spermathecal apparatus ( Figures 7C & 8 ). Cervix elongate funnel-shaped, major duct as wide as atrium, atrium cylindrical with a “V-shaped” notch joint with major duct. Gnathosoma . CHELICERA. ( Figure 7D ): with movable digit 29 (27–32) long, bearing a tooth; fixed digit 27 (25–28) long, bearing five visible teeth, pilus dentilis 6 (6–7) long, located at fourth tooth. PALP ( Figure 11D ): trochanter with two setae; femur with a spatulate seta and four simple setae; genu with two stouts and four simple setae; tibia with simple setae; tarsal apotele 2-tined as in deutonymph. HYPOSTOME ( Figure 12D ): with three pairs of hypostomal setae ( h1 , h2 and h3 ) and one pair of palpcoxal setae ( pc ). Deutosternal groove with seven rows of denticles; corniculi horn-like. FIGURE 6. Neoseiulus barkeri (deutonymph). A. leg I; B. leg II; C. leg III; D. leg IV. Legs ( Figure 9 ). Leg I 370 (358–380) long; Leg II 281 (279–295) long; Leg III 274 (268–282) long; Leg IV 385 (377–395) long; number of setae of legs I–IV same as those in deutonymph. ADULT MALE (n=5, Figure 10 , Table 1 ) Idiosoma ( Figure 10A , Table 1 ). 295 (287–303) long, 185 (178–189) wide. DORSUM: smooth, ovoid, bearing 19 pairs of setae, 14 pairs of visible lyrifissures ( id1, id2, id4, id5, id6, idl2, idl3, idl4, idm1, idm2, idm3, idm5, idm6 and is1 ) and five pairs of solenostomes ( gd1 , gd4 , gd6 , gd8 and gd9 ). Marginal setae r3 and R1 on dorsal shield, Lengths of setae: j1 16 (14–20), j3 20 (17–21), j4 15 (14–17), j5 16 (14–18), j6 18 (17–19), r3 20 (19–20), z2 18 (16–19), z4 19 (16–22), z5 17 (15–19), s4 22 (19–24), S2 21 (18–22), S4 20 (18–22), S5 19 (26–21), J2 19 (15–20), J5 12 (11–13), Z1 18 (16–20), Z4 29 (26–33), Z5 35 (34–37), R1 18 (17–19).VENTRUM ( Figure 10B ): sternogenital shield smooth, several striae lateral margin, 123 (117–132) long from middle of anterior margin to posterior margin, 67 (64–70) wide, middle of anterior margin convex, posterior margin of shield nearly straight, with five pairs of smooth setae ( st1 , st2, st3, st4 and st5 ) and three pairs of lyrifissures ( iv1 , iv2 and iv3 ). Peritremes extending close to j1 level. Ventrianal shield reticulated, approximately triangle, middle of anterior margin with rounded median lobe, 121 (117–126) long, 149 (143–153) wide (at corner of anterior margin), with four pairs of preanal setae ( JV1 , JV2, ZV1 and ZV2 ) and three pairs of lyrifissures, a pair of solenostomes gv3 distance 18 (16–20). A pair of JV5 and a pair of lyrifissure on membranous cuticles. Lengths of setae: st1 22 (19–25), st2 20 (17–21), st3 19 (14–23), st4 20 (18–21), st5 18 (17–19), JV1 19 (16–21), JV2 18 (17–20), JV4 21 (20–23), JV5 28 (27–30), ZV2 19 (16–23) . FIGURE 7. Neoseiulus barkeri (adult female). A. dorsal idiosoma; B. ventral idiosoma; C. variations of spermatheca; D. chelicera. FIGURE 8. Neoseiulus barkeri (adult female). Variations of spermatheca. FIGURE 9. Neoseiulus barkeri (adult female). A. leg I; B. leg II; C. leg III; D. leg IV. FIGURE 10. Neoseiulus barkeri (adult male). A. dorsal idiosoma; B. ventral idiosoma; C. chelicera. FIGURE 11. Palp of Neoseiulus barkeri . A. larva; B. protonymph; C. deutonymph; D. adult female. FIGURE 12 . Gnathosoma of Neoseiulus barkeri . A. larva; B. protonymph; C. deutonymph; D. adult female. Gnathosoma . CHELICERA ( Figure 10C ): movable digit 25 (24–25) long, fixed digit 23 (23–24) long; Spermatodactyl T-shaped. PALP: Chaetotaxy same as female. HYPOSTOME: chaetotaxy same as female. Legs . Leg Chaetotaxy same as female. Addition of setae on leg segments . Most leg setae added during the postembryonic development of N. barkeri appear first mainly in the deutonymph, with more setae added on trochanter, femur, genu and tibia ( Table 1 ). The numbers of setae are stable on coxae and basitarsi from larva to adult ( Table 1 ). Specimens examined: Laboratory-reared : 1 larva , 21.X.2018 ; 2 larvae , 3 protonymphs, 2 deutonymphs, 22.X.2018 ; 7 protonymphs, 1 deutonymph, 23.X.2018 ; 1 larva , 1 ♀ , 28.X.2018 ; 1 larva , 4 deutonymphs, 29.X.2018 ; 3 larvae , 4 protonymphs, 2 deutonymphs, 1.XI.2018 ; 1 protonymph, 3 deutonymphs, 16, II. XI.2018 ; 1 larva , 3 protonymphs, 1 deutonymph, 4 ♀♀ , 7 66, 4.XI.2018 ; 1 larva , 1 protonymph, 4 66, 5.XI.2018 ; 1 6, 12.XI.2018 ; 10 ♀♀ , 20.XI.2018 ; 2 protonymphs, 21.XI.2018 ; 5 ♀♀ , 22.11.2018 ; 4 larva , 3 ♀♀ , 1 6, 23.XI.2018 ; 1 ♀ , 24.XI.2018 ; 3 ♀♀ , 1.III.2019 ; 1 deutonymph, 11 ♀♀ , 5.III.2019 ; 1 ♀ , 20.V.2019 , coll. P. Wang.