Amblyseius bellatulus Tseng, 1983

Liao, J. - R., Ho, C. - C. & Ko, C. - C., 2017, Amblyseius bellatulus Tseng (Acari: Phytoseiidae): neotype designation with first description of a male, Acarologia 57 (2), pp. 323-335 : 325-333

Amblyseius bellatulus Tseng, 1983 ( Figures 1-4 )

Amblyseius (Amblyseius) bellatulus Tseng, 1983: 38 .

Neotype Designation

Amblyseius bellatulus was described by Y. H. Tseng in 1983 from Mingchien (now Mingjian Township), Nantou Hsien on Morus alba . As mentioned in the introduction the mite collection of Y. H. Tseng does not longer exist ( BAPHIQ, 2009), according to Article 75.3.4 of the International Code of Zoological Nomenclature ( International Commission on Zoological Nomenclature, 1999), we here designate adult females we collected as neotype of A. bellatulus to clarify its taxonomic status and provide a complete description. Additionally, as male specimens were not known, we provide male description for the first time.

Description: Female (n= 10). Dorsum ( Figure 1A ) — Idiosomal setal pattern: 10A:9B/JV-3:ZV. Dorsal shield lightly sclerotized, smooth, with lateral reticulation, 382 384 (353 – 449) long, 202 212 (192 – 250) wide at level of s4, 228 228 (212 – 276) wide at level of S4; with seven pairs of solenostomes (gd1, gd2, gd4, gd5, gd6, gd8, gd9), ten pairs of poroids (id1, id1a, id2, id4, is1, idl1, idl3, idl4, idm5, idm6); length of dorsal setae: j1 23 28 (23 – 32), j3 34 40 (34 – 46), j4 5 7 (5 – 13), j5 4 5 (4 – 7), j6 6 7 (4 – 8), J2 4 7 (4 – 9), J5 5 6 (4 – 9), z2 11 10 (8 – 11), z4 11 11 (8 – 13), z5 5 6 (4 – 8), Z1 8 8 (7 – 10), Z4 52 52 (47 – 57), Z5 119 136 (117 – 158), s4 46 49 (43 – 61), S2 10 11 (9 – 13), S4 5 8 (5 – 11), S5 6 7 (6 – 9), r3 21 19 (17 – 21), R1 13 10 (8 – 13). All setae smooth, except Z4 and Z5 slightly serrate.

Venter ( Figure 1B ) — Sternal shield smooth, posterior margin almost straight, wider than long, 66 69 (62 – 73) long, 87 94 (84 – 114) wide at st3 level, with three pairs of setae st1 25 27 (24 – 29), st2 24 24 (21 – 26), st3 23 23 (17 – 26) and two pairs of poroids (pst1, pst2). Metasternal platelets tear-shaped, with a pair metasternal setae, st4 22 19 (14 – 22), and one pair of poroids (pst3). Genital shield smooth, st5 23 22 (16 – 26), 77 78 (73 – 96) wide. Distances between st1-st1 59 58 (53 – 73), st2- st2 63 63 (59 – 75), st3- st3 78 74 (67 – 80), st1- st3 63 64 (61 – 74), st5- st5 59 64 (58 – 73). Ventrianal shield smooth, almost pentagonal, with slightly waist at JV2 level; 121 131 (121 – 151) long, 100 98 (90 – 117) wide at level of ZV2 and 86 90 (84 – 103) wide at level of anus; with three pairs of pre-anal setae, solenostome gv3 crescentic, JV1 13 15 (11 – 18), JV2 10 13 (10 – 18), ZV2 9 11 (9 – 14). Setae JV4 11 10 (7 – 11), JV5 45 51 (45 – 61), ZV1 15 16 (12 – 19), ZV3 9 10 (9 – 11) on interscutal membrane. All ventral setae smooth. Two metapodal plates 18 20 (18 – 23) long, 4 6 (4 – 7) wide, 12 15 (12 – 17) long, 2 2 (1 – 3) wide.

Peritreme ( Figure 1 A-B) — Peritreme extending beyond to j1, peritrematic shield smooth, lightly sclerotized, with one pair of solenostome (gd3).

Spermatheca ( Figure 1D ) — Calyx of spermath- eca funnel-shaped and atrium well distinct with neck, embolus not visible, with a thin major duct.

Chelicera ( Figure 1C ) — Movable digit 31 32 (30 – 36) long, with three teeth; fixed digit 27 29 (26 – 34), with 10 teeth, pilus dentilis.

Legs ( Figure 2 ) — Coxal formula 2, 2, 2, 1. Chaetotaxy (femur to basitarsus): leg I, 2-3/1-2/2- 2, 2-2/1-2/1-2, 2-2/1-2/1-2, 1-1/1-1; leg II, 2-3/2- 2/0-1, 2-2/0-2/0-1, 1-1/1-2/1-1, 1-1/1-1; leg III, 1- 2/1-1/0-1, 1-2/1-2/0-1, 1-2/1-1/1-1, 1-1/1-1; leg IV, 1-2/1-1/0-1, 1-2/1-2/0-1, 1-1/1-2/0-1, 1-1/1-1. Macrosetae: Sge II (pd2) 27 29 (26 – 33), Sge III (ad2) 30 31 (27 – 37), Sge IV (ad2) 50 50 (40 – 59), Sti IV (ad) 45 46 (40 – 51), St IV (pd) 73 73 (66 – 84).

Male (n= 2). Dorsum ( Figure 3A ) — Idiosomal setal pattern: 10A:9B/JV-3, 4:ZV-1, 3. Dorsal shield lightly sclerotized, smooth, with lateral reticulation, 264 (248 – 280) long, 178 (161 – 195) wide at level of s4, 138 (127 – 149) wide at level of S4; with seven pairs of solenostomes (gd1, gd2, gd4, gd5, gd6, gd8, gd9), ten pairs of poroids (id1, id1a, id2, id4, is1, idl1, idl3, idl4, idm5, idm6); length of dorsal setae: j1 20 (20 – 2), j3 28 (28 – 29), j4 5.4 (5 – 6), j5 5 (4 – 5), j6 5 (4 – 6), J2 5 (5 – 5), J5 5 (4 – 6), z2 10 (10 – 11), z4 9 (8 – 10), z5 4 (4 – 4), Z1 9 (8 – 9), Z4 35 (35 – 35), Z5 81 (77 – 85), s4 34 (34 – 34), S2 9 (9 – 9), S4 7 (7 – 7), S5 6 (6 – 6), r3 15 (15 – 16), R1 9 (7 – 11). All setae smooth, except Z4 and Z5 slightly serrate.

Venter ( Figure 3B ) — Sternogenital shield smooth, with slightly lateral reticulation, posterior margin almost straight, longer than wide 116 (110 – 123) long, 64 (55 – 73) wide at level st2, with five pairs of setae st1 18 (16 – 19), st2 18 (16 – 20), st3 16 (13 – 19), st4 14 (11 – 17), st5 14 (13 – 14) and three pairs of poroids (pst1, pst2, pst3); distance between st1-st1 42 (40 – 43), st2-st2 49 (46 – 52), st3-st3 50 (47 – 54), st4-st4 38 (36 – 40), st5-st5 30 (27 – 33), st1-st5 102 (97 – 106). Ventrianal shield subtriangular, with slightly reticulation, 108 (103 – 114) long, 137 (129 – 144) wide at level of anterior corner and 61 (61 – 62) wide at level of anus, fused with peritrematic shield cingulum; with three pairs of pre-anal setae, solenostome gv3 crescentic, JV1 9 (9 – 9), JV2 10 (10 – 10), ZV2 8 (8 – 8); JV5 20 (17 – 22) on interscutal membrane. All ventral setae smooth.

Peritreme ( Figure 3 A-B) — Peritreme extending to seta j1 level; peritrematic shield lightly sclerotized, with one pair of solenostome (gd3).

Chelicera ( Figure 3 C-D) — Movable digit 21 (21 – 22) long, with one tooth; fixed digit 22 (20 – 24), with 8 teeth, pilus dentilis. Spermatodactyl Ushaped, shaft 34 (30 – 37) long, heel rounded, foot 18 (17 – 19) long, with rounded toe and lateral thornlike projection.

Legs ( Figure 4 ) — Coxal formula 2, 2, 2, 1. Chaetotaxy (femur to basitarsus): leg I, 2-3/1-2/2- 2, 2-2/1-2/1-2, 2-2/1-2/1-2, 1-1/1-1; leg II, 2-3/2- 2/0-1, 2-2/0-2/0-1, 1-1/1-2/1-1, 1-1/1-1; leg III, 1- 2/1-1/0-1, 1-2/1-2/0-1, 1-2/1-1/1-1, 1-1/1-1; leg IV, 1-2/1-1/0-1, 1-2/1-2/0-1, 1-1/1-2/0-1, 1-1/1-1. Macrosetae: Sge II (pd2) 20 (19 – 20), Sge III (ad2) 20 (20 – 20) Sge IV (ad2) 29 (28 – 30), Sti IV (ad) 26 (25 – 26), St IV (pd) 56 (56 – 56).

Material examined — Neotype female: TARI, Wufeng District , Taichung, from Toona sinensis , 17.xii.2001, C. C. Ho ( NTU).

Additional material examined — Hualien County, one female from rice leaf sheath, 2.xi.1977, K. C. Lo ( TARL); Wanfeng Village, Wufeng District , Taichung City, one female from Polygonum perfoliatum , 3.ii.1978, C. C. Ho ( TARI); Wanfeng Village, Wufeng District , Taichung City, one female from Bothriochloa ischaemum , 15.ii.1978, C. C. Ho ( TARI); Wanfeng Village, Wufeng District , Taichung City, one female from mushroom, 15.xii.1981, K. C. Lo ( TARI); TARI , Wufeng District , Taichung City, two females from Zea mays , 18.x.1985, C. C. Ho ( TARL); TARI , Wufeng District , Taichung City, 17 females 1 male from Ageratum conyzoides , 22.xi.1985, C. C. Ho ( TARI); NPIA , two females from Ageratum conyzoide , 22.xi.1985, C. C. Ho ( TARL); Erlin Township , Changhua County, one female from Vigna unguiculata , 14.xii.1986, S. M. Yu ( NPUST); Mingjian Township , Nantou County, two females from Ampelopsis brevipedunculata , 24.xii.1985, C. C. Ho ( NTU); TARI , Wufeng District , Taichung City, one female from Zea mays , 4.vii.1987, C. C. Ho ( TARI); Baihe District , Tainan City , one female from Sambucus formosana , 23.vi.1988, S. M. Yu ( NMNS); TARI , Wufeng District , Taichung City, one female from Ageratum houstonianum , 12.x.1988, S. M. Yu ( NMNS); TARI , Wufeng District , Taichung City, two females from Alternanthera sessilis , 17.x.1988, S. M. Yu ( NPUST); TARI , Wufeng District , Taichung City, one female from Eclipta prostrata , 17.x.1988, S. M. Yu ( NMNS); TARI , Wufeng District , Taichung City, nine females from Polygonum perfoliatum , 17.x.1988, S. M. Yu ( NCHU); TARI , Wufeng District , Taichung City, two females (MZLQ-7644, 7645) from Arachis hypogaea , 17.x.1988, S. M. Yu ( ESALQ-USP); TARI , Wufeng District , Taichung City, one female (MZLQ-7643) from unknown plant, 18.x.1988, S. M. Yu ( ESALQ- USP); Caotun Township , Nantou County, three females from Psidium guajava , 27.x.1988, S. M. Yu ( NTU); TARI , Wufeng District , Taichung City, two females from Ipomoea acuminata , 27.x.1988, S. M. Yu ( NTU); TARI , Wufeng District , Taichung City, three females from Zingiber officinale , 2.xi.1988, S. M. Yu ( TARL); TARI , Wufeng District , Taichung City, one female from Monorfiae choartiae, 2.xi.1988, S. M. Yu ( TARL); Caotun Township , Nantou County, 11 females from Psidium guajava , 2.xi.1988, S. M. Yu ( NPUST); TARI , Wufeng District , Taichung City, two females from Ageratum houstonianum , 16.xi.1988, S. M. Yu ( NTU); TARI , Wufeng District , Taichung City, two females from Ipomoea acuminata , 24.xi.1988, S. M. Yu ( NTU); TARI , Wufeng District , Taichung City, one female from Rorippa indica , 30.xi.1988, S. M. Yu ( TARL); TARI , Wufeng District , Taichung City, two females one male from Oryza sativa , 2.xii.1988, S. M. Yu ( NCHU); TARI , Wufeng District , Taichung City, one female from Ziziphus mauritiana , 7.xii.1988, C. C. Ho ( TARI); Sanxiantai, Chenggong Township , Taitung County, one male from Calophyllum inophyllum , 4.iv.1989, C. C. Ho ( TARL); TARI , Wufeng District , Taichung City, one female from Solanum melongena 25.vi.1991, C. C. Ho ( NMNS); TARI , Wufeng District , Taichung City, two females from Solanum melongena 4.vi.1991, C. C. Ho ( TARI); TARI , Wufeng District , Taichung City, one female from Solanum melongena 11.vi.1991, C. C. Ho ( NMNS); TARI , Wufeng District , Taichung City, three females rear from unknown plant, 3.vii.1991, C. C. Ho ( TARI); TARI , Wufeng District , Taichung City, one female from Solanum melongena 4.vii.1991, C. C. Ho ( NPUST); TARI , Wufeng District , Taichung City, three females from Solanum melongena 6.vii.1991, C. C. Ho ( NMNS); TARI , Wufeng District , Taichung City, nine females two males from Solanum melongena , 16.vii.1991, C. C. Ho ( NTU); TARI , Wufeng District , Taichung City, one female from Solanum melongena , 23.vii.1991, C. C. Ho ( NTU); TARI , Wufeng District , Taichung City, one female rear from unknown plant, 6.xi.1993, C. C. Ho ( NTU); Lucao Township , Chiayi County, one female from Lagenaria siceraria soil, 14.viii.2001, C. C. Ho ( NTU); Dayuan District , Taoyuan City, one female from Allium fistulosum soil, 25.x.2001, C. C. Ho ( NTU) .

Remarks — Tseng (1983) described this species by using a single female specimen collected from Mingchien (now Mingjian Township), Nantou Hsien, on Morus alba . We collected two female specimens from the type locality on Ampelopsis brevipedunculata , but they were in poor condition. Consequently, the neotype specimen was selected from among the entire collection depending on the slide condition. The neotype locality is Wufeng District, Taichung, which is not far from the type locality ( Figure 5 ).

The females of this species are unique among the known Amblyseius species from Taiwan because of the following characters: dorsal shield with lateral reticulation, ventrianal shield pentagonal with slightly lateral concaved, calyx of spermatheca funnel-shaped. A comparison of different body measurements among the holotype, neotype, and remaining specimens of A. bellatulus is provided in Table 1. Most specimens were similar to the neotype, with little morphological differences. We observed only one specimen with a larger body size and longer idiosomal setae (e.g. dorsal shield 449 long, 250 wide). Tseng (1983) reported the chaetotaxy of genu I-IV: 2-2/1-2/1-2, 1-2/1-2/0-1, 1-2/1- 2/0-1, 1-2/1-2/0-1". We observed the chaetotaxy of leg I-IV and found that the chaetotaxy of genu I-IV differs from the original description: 2-2/1-2/1-2, 2- 2/0-2/0-1, 1-2/1-2/0-1, 1-2/1-2/0-1. With regard to adenotaxy and poroidotaxy, Tseng (1983) reported "at least five pairs of pores on the dorsal shield". On the basis of his illustration, we observed three pairs of solenostomes (gd6, gd8, gd9). In the present study, we observed seven pairs of solenostomes (gd1, gd2, gd4, gd5, gd6, gd8, gd9), and ten pairs of poroids (id1, id1a, id2, id4, is1, idl1, idl3, idl4, idm5, idm6). The differences between the reported and observed adenotaxy and poroidotaxy may be due to the quality of microscopes.

T1: Comparisons on measurements 1 (µm) of Amblyseius bellatulus between (1) holotype (in Tseng 1983), (2) presently studied ABLE neotype and (3) ten females including neotype

By comparing the collection records of this A. bellatulus , we observed that this species was mostly collected from central Taiwan; however, one spec- imen was collected from northern Taiwan and another from eastern Taiwan. Therefore, this species may be more widely distributed than is evident from the collection. We also observed A. bellatulus occurred on various plants, although these mites mostly inhabit weeds, they also inhabit some economically valuable plants (e.g., corn plants, egg- plants, and guava). Ho and Chen (2001) reported that A. bellatulus could prey on melon thrips (Thrips palmi) in the field. Therefore, we consider A. bellatulus need further experiments for confirmation of the biocontrol potential.

Figures

FIGURE 1: Amblyseius bellatulus Female: A – Dorsal shield; B – Ventral idiosoma; C – Chelicera; D – Spermatheca.

FIGURE 2: Amblyseius bellatulus Female: Legs (A – leg I dorso-anterior view; B – leg II dorso-anterior view; C – leg III dorsal view; D – leg IV dorso-anterior view).

FIGURE 3: Amblyseius bellatulus Male: A – Dorsal shield; B – Ventral idiosoma; C – Chelicera; D – Ventral view of spermatodactyl.

FIGURE 4: Amblyseius bellatulus Male: Legs (A – leg I dorso-anterior view; B – leg II dorso-posterior view; C – leg III dorso-posterior view; D – leg IV dorso-posterior view).

FIGURE 5: The distribution map of Amblyseius bellatulus from Taiwan.