Euseius nicholsi (Ehara & Lee), E. sojaensis (Ehara), and Gynaseius santosoi (Ehara) are reported for the first time from Taiwan. The new records were re-described based on Taiwanese specimens collected from various plants. In addition, a new species, E. oolong sp. nov., was described and illustrated. Identification keys for Taiwanese species of Euseius Wainstein and world species of genus Gynaseius Wainstein are provided.
Introduction
Phytoseiid mites have been intensively surveyed in Taiwan during the past several decades (Ehara 1970; Lo 1970; Tseng 1972; 1973; 1975; 1976; Chang & Tseng 1978; Tseng 1983; Ho & Lo 1989; Ho et al. 2003) because of their potential as biological control agent (Huffaker et al. 1970; McMurtry et al. 1970; 2013). Knowledge regarding the fauna of Phytoseiidae in Taiwan is still increasing, with detailed investigations conducted by the present authors. To date, 59 species have been recorded from Taiwan and neighboring islands (Ehara 1970; Lo 1970; Tseng 1972; 1973; 1975; 1976; Chang & Tseng 1978; Tseng 1983; Ho & Lo 1989; Ho et al. 2003; Liao et al. 2017a; 2017b; 2017c).
The genus Euseius Wainstein is a large genus in the subfamily Amblyseiinae with about 190 valid species (Demite et al. 2018). In general, Euseius species are recorded in tropical and subtropical areas, especially in Africa (approximately 35% of total species) (Moraes et al. 2001; Chant & McMurtry 2005; 2007). Euseius species are considered to be pollen feeding generalist predators with type IV feeding habits (McMurtry et al. 2013). Some of them, such as E. scutalis (Athias-Henriot), may survive in the absence of prey by sucking plant tissues (Nomikou et al. 2003; Adar et al. 2012). Several studies have noted the biological potential of Euseius species to control small agricultural pests (Döker et al. 2014; Lopes et al. 2015; Liao et al. 2017a; De Alfaia et al. 2018). Among them, E. gallicus Kreiter & Tixier has been used commercially for whiteflies and thrips control (Biobest, 2018). In a decade-long survey conducted by the authors of the present study, six species—E. aizawai (Ehara & Bhandhufalck), E. circellatus (Wu & Li), E. daluensis Liao & Ho, E. macaranga Liao & Ho, E. ovalis (Evans), and E. paraovalis Liao & Ho—were found in Taiwan (Liao et al. 2017a).
The genus Gynaseius Wainstein also belongs to the subfamily Amblyseiinae, which contains 12 valid species that have been recorded in various host plants (e.g. rice, soybean, blackberry, papaya, and Hibiscus sp.) in the Pacific area, except G. larum El-Banhawy & Knapp, which has been identified from an unknown host in Kenya (Chant & McMurtry 2006; El-Banhawy & Knapp 2011; Demite et al. 2018). This genus is unique in that its peritrematic shield is not fused anteriorly with the dorsal shield in the Amblyseiinae (Chant & McMurtry 2006).
In the present study, we described a new species and presented three new records that were observed during our surveys in Taiwan. Identification keys for Taiwanese species of Euseius and world species of Gynaseius were included.
Materials and Methods
Specimens examined in this study were collected from various plants from the main island and surrounding islands of Taiwan and also a trip in Guangzhou for comparison. Specimens examined under Olympus BX51 microscope, and measurements were taken using a stage-calibrated ocular micrometers and as well as ImageJ 1.47 (Schneider et al. 2012). Photos were taken by using Motic® Moticam 5+ camera attached to the microscope. All measurements were provided in micrometers and holotype measurements are shown in bold type for the new species and E. nicholsi, followed by their mean and range in parenthesis, missing values were code with question mark “?”. The general terminology used for morphological descriptions in this study follows that of Chant & McMurtry (2007), while for idiosomal seta terminology followed Rowell et al. (1978) and Chant & Yoshida-Shaul (1991; 1992); for adenotaxy and poroidotaxy terminology we followed Beard (2001).
Type specimens and voucher specimens were deposited in the following institutions: GIABR (Guangdong Institute of Applied Biological Resources, Guangzhou, China), NCHU (Department of Entomology, National Chung Hsing University, Taichung, Taiwan), NMNS (National Museum of Natural Science, Taichung, Taiwan), NTU (Department of Entomology, National Taiwan University, Taipei, Taiwan), TARL (Taiwan Acari Research Laboratory, Taichung City, Taiwan). Other specimens were received on loan from acarological collections of HUM (Hokkaido University Museum, Sapporo, Japan) and NSMT (National Museum of Nature and Science, Tsukuba, Japan). If necessary, the locality names were translated using the Geographic Name Information System, Department of Land Administration, Ministry of the Interior (Taiwan) ( http://gn.moi.gov.tw/geonames/Translation/Translation.aspx).
Results
Family Phytoseiidae Berlese
Subfamily Amblyseiinae Muma
Tribe Euseiini Chant & McMurtry
Subtribe Euseiina Chant & McMurtry
Genus Euseius Wainstein
Euseius oolong Liao & Ho sp. nov.
(Figures 1–2)
Diagnosis. Female dorsal surface mostly reticulated, bearing 19 pairs of dorsal setae (including r3, R1). All setae smooth, except Z5 serrated. Five pairs of solenostomes, (gd2, gd5, gd6, gd8, gd9) visible on the dorsal shield. Peritreme extending to level of setae z2. Sternal shield with three pairs of setae; ventrianal shield bearing three pairs of pre-anal setae, JV1 migrate next to JV2, with solenostomes. Fixed digit of chelicera with five teeth; movable digit with one tooth. Calyx of spermatheca short and cup-shaped with distal half only lightly sclerotized. Leg III and leg IV both with three pair of macrosetae; genu II with seven setae.
Female (n=6).
A lightly sclerotized mite. Idiosomal setal pattern: 10A:9B/JV-3:ZV.
Dorsum (Figure 1A). Dorsal shield laterally reticulated; 328 341 (324–361) long (j1–J5 level) and 237 246 (236–266) wide at level of j6, 221 237 (221–260) wide at level of S4; five pairs of solenostomes on dorsal shield, (gd2, gd4, gd6, gd8, gd9), seven pairs of lyrifissures (id1, id1a, id2, id4, idl3, idl4, idm5); muscle-marks (sigilla) visible on podosoma; length of setae: j1 32 28 (24–32), j3 20 22 (20–25), j4 7 8 (7–10), j5 7 8 (7–11), j6 9 9 (6–11), J2 8 10 (8–12), J5 6 5 (3–6), z2 12 15 (12–18), z4 11 13 (11–19), z5 6 8 (6–10), Z1 8 10 (7–15), Z4 8 11 (8–16), Z5 53 58 (53–63), s4 18 25 (18–36), S2 13 16 (13–18), S4 17 22 (17–27), S5 22 25 (22–29), r3 9 12 (9–15), R1 9 10 (9–13). All setae smooth, except Z5 slightly serrate.
Peritreme (Figure 1A). Peritreme extending beyond z2 level, peritrematic shield smooth, lightly sclerotized, with one pair of solenostomes (gd3).
Venter (Figure 1B). Sternal shield smooth, posterior margin with medium projection, much wider than long, 61 61 (51–70) long, 94 93 (86–96) wide, with three pairs of setae st1 26 27 (26–31), st2 23 25 (23–28), st3 26 24 (22–26), and two pairs of lyrifissures (pst1, pst2). Exopodal shield at coxae I-IV. Metasternal platelets tear-shaped, with one pair metastemal setae, st4 21 21 (19–23), with one pair of lyrifissuress (pst3). Genital shield smooth, with one pair of genital setae st5 20 23 (15–28), 75 87 (75–92) wide at level of genital setae. Distances between st1-st1 49 54 (45–61), st2-st2 63 62 (48–69), st3-st3 75 74 (65–79), st1-st3 56 58 (52–63), st5-st5 68 76 (68–82). Ventrianal shield vase-shaped 96 102 (96–108) long, 49 49 (45–56) wide at level of ZV2, 82 81 (77–85) wide at level of anus; with three pairs of pre-anal setae, JV1 migrate next to JV2, JV1 26 24 (19–26), JV2 18 19 (15–24), ZV2 15 17 (13–20), solenostomes gv3 crescentic; Pa 17 13 (9–17), Pst 14 12 (9–15) on shield. Setae JV4 11 10 (8–11), JV5 24 29 (24–34), ZV1 20 18 (16–20), ZV3 8 8 (8–8) on interscutal membrane. All ventral setae smooth. Two metapodal plates 23 22 (20–26) long, 4 6 (4–9) wide, 10 10 (9–11) long, 1 2 (1–3) wide.
Chelicera (Figure 1C). Movable digit 23 24 (22–26) long, with one tooth; fixed digit 23 24 (23–25) long, anterior half with five teeth, with pilus dentilis.
Spermatheca (Figure 1D). Calyx cup-shaped with distal half only lightly sclerotized, 7 6 (5–8) long, 4 3 (3–4) wide, atrium incorporated within the calyx, without neck, with a thin major duct, minor duct visible.
Legs (Figure 2). Coxal formula 2-2-2-1. Chaetotaxy (femur to basitarsus): leg I, 2-3/2-2/1-2, 2-2/1-2/0-2, 2-2/1-2/1-2, 1-1/1-1; leg II, 2-3/1-2/1-1, 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, 1-1/1-2/1-1, 1-1/1-1; leg IV, 1-2/1-1/0-1, 1-2/1-2/0-1, 1-1/1-2/1-0, 1-1/1-1. Macrosetae: Sge II (pd2) 23 23 (20–24), Sge III (ad2) 26 30 (26–35), Sti III (ad) 23 23 (19–26), St III (d) 26 26 (24–30), Sge IV (ad2) 44 44 (37–50), Sti IV (ad) 32 34 (27–37) and St IV (d) 50 58 (50–61).
Type specimens. Female Holotype: TAIWAN: Tea Research and Extension Station, Yangmei Dist., Taoyuan City (24°33.924′ N, 121°05.433′ E, 771m), one female (no. 1688–3) from Camellia sinensis (L.) O.Kuntze var. oolong (Theaceae), 11.v.2016, J. R. Liao (NTU). Paratypes: two females (no. 1688–1, 2) data same with holotype (NTU). CHINA: Sun Yat-sen University, Guangzhou City, Guangdong Province, one female (no. 2028–2) from Macaranga tanarius (Euphorbiaceae), 23.ii.2017, J. R. Liao (NMNS); Guangdong Institute of Applied Biological Resources, Guangzhou City, Guangdong Province, two females (no. 2029–1, 2) from Bauhinia purpurea (Caesalpiniaceae), 23.ii.2017, J. R. Liao (GIABR).
Etymology. The epithet oolong refers to habitat plants of holotype specimens; oolong is a special tea variety.
Distribution. Asia: China (Guangdong (present study)), Taiwan (present study).
Remarks. This new species is similar to E. aizawai (Ehara & Bhandhufalck), E. australis (Wu & Li), E. daluensis (Liao & Ho), E. finlandicus (Oudemans), E. jiangxiensis Wu & Ou, E. nicholsi (Ehara & Lee), E. sojaensis (Ehara), E. utilis (Liang & Ke), E. wyebo (Schicha & Corpuz-Raros). Differences between E. oolong sp. nov. and related species are given in Table 1. This species is also different based on its short and cup-shaped calyx of spermatheca which is fuunel-shaped and/or longer in above mentioned closely related species.
This species is recorded in Taiwan and Southern China. However, few specimens have been found. The biological control potential of this species needs further study in the future.
FIGURES 1.
Euseius oolong sp. nov. Female, A. dorsal shield, B. ventral idiosoma, C. chelicera, D. spermatheca.
FIGURES 2.
Euseius oolong sp. nov. Female, legs A. leg I anterior view, B. leg II posterior view, C. leg III dorsal view, D. leg IV anterior view.
TABLE 1.
Differences between Euseius oolong sp.nov. and related species.
Euseius nicholsi (Ehara & Lee, 1971) (Figures 3–5)
Amblyseius (Amblyseius) nicholsi Ehara & Lee 1971: 67.
Euseius nicholsi—Wu et al. 1997: 115.
Female (n=3).
A lightly sclerotized mite. Idiosomal setal pattern: 10A:9B/JV-3:ZV.
Dorsum (Figure 4A). Dorsal shield most surface strongly reticulated, 360 353 (350–360) long (j1-J5 level) and 256 250 (243–256) wide at level of j6, 236 237 (231–243) wide at level of S4; with seven pairs of solenostomes (gd1, gd2, gd4, gd5, gd6, gd8, gd9), seven pairs of lyrifissures (id1, id1a, id2, is1, idl3, idl4, idm5, idm6); muscle-marks (sigilla) visible on podosoma; length of dorsal setae: setae j1 34 32 (29–34), j3 28 27 (26–28), j4 11 9 (7–11), J5 ? 7 (5–10), j6 ? 7 (5–10) J2 14 10 (7–14), J5 6 5 (4–6), z2 17 15 (14–17), z4 17 18 (17–19), z5 11 8 (7–11), Z1 13 10 (8–13), Z4 15 13 (10–15), Z5 60 60 (60–60), s4 29 27 (24–29), S2 18 15 (12–18), S4 25 21 (18–25), S5 26 22 (19–26), r3 14 17 (14–19), R1 ? 12 (11–13). All setae smooth, except Z5 slightly serrate.
Peritreme (Figure 4A). Peritreme extending over z2, peritrematic shield smooth, lightly sclerotized, with one pair of solenostomes (gd3), one pair of lyrifissures (id3).
Venter (Figures 1, 4B). Sternal shield smooth, projection of posterior margin invisible, wider than long, 54 61 (54–65) long, 88 89 (88–89) wide at level of st3, with three pairs of setae st1 27 27 (26–27), st2 28 24 (20–28), st3 24 20 (15–24), and two pairs of lyrifissures (pst1, pst2). Exopodal shield at coxae II-IV. Metasternal platelets tear-shaped, with one pair metasternal setae, st4 21 18 (16–21), and one pair of lyrifissures (pst3). Genital shield smooth, 85 87 (82–93) wide at level of genital setae, with one pair of genital setae st5 27 22 (16–27). Distances between st1–st1 52 56 (52–60), st2–st2 60 63 (60–65), st3–st3 71 73 (71–75), st1–st3 56 59 (56–62), st5–st5 76 76 (76–77). Ventrianal shield smooth, vase-shaped, 95 90 (87–95) long, 45 48 (45–51) wide at level of ZV2, 75 72 (65–77) wide at level of anus; with three pairs of pre-anal setae, JV1 migrate next to JV2, JV1 28 24 (21–28), JV2 26 23 (20–26), ZV2 18 15 (13–18), solenostomes gv3 crescentic; Pa 15 13 (12–15), Pst 16 14 (11–16) on shield. Setae JV4 10 10 (10–10), JV5 29 32 (29–35), ZV1 23 19 (16–23), ZV3 13 13 (13–13) on interscutal membrane. All ventral setae smooth. Two pairs of metapodal platelets 22 22 (22–22) long, 5 4 (4–5) wide, 8 11 (8–13) long, 1 2 (1–2) wide.
Chelicera (Figure 4C). Movable digit 21 24 (21–27) long, with one tooth; fixed digit 24 24 (24–24) long, anterior half with four teeth, with pilus dentilis.
Spermatheca (Figure 4D). Calyx funnel-shaped, 7 7 (7–8) long, 4 4 (3–4) wide, atrium with indistinguible embolus, connect with a major duct, minor duct visible.
Legs (Figure 5). Coxal formula 2-2-2-1. Chaetotaxy (femur to basitarsus): leg I, 2-3/2-2/1-2, 2-2/1-2/1-2, 2-2/1-2/1-2, 1-1/1-1; leg II, 2-3/1-2/1-1, 1-2/0-2/0-1, 1-1/1-2/1-1, 1-1/1-1; leg III, 1-2/1-1/0-1, 1-2/1-2/1-0, 1-1/1-2/1-1, 1-1/1-1; leg IV, 1-2/1-1/0-1, 1-2/1-2/0-1, 1-1/1-2/1-0, 1-1/1-1. Macrosetae: Sge II (pd2) 21 20 (19–21) [25]; Sge III (ad2) 31 28 (25–31), Sti III (ad) 25 26 (25–27), St III (d) 24 25 (24–27); Sge IV (ad2) 48 50 (48–53), Sti IV (ad) 38 38 (38–39) and St IV (d) 60 68 (60–73).
Specimens examined. CHINA: Chai Wan, Hong Kong, one holotype female (NSMT-Ac-13078) from grass, 18.x.1970, S. Ehara (NSMT); TAIWAN: Shoushan National Nature Park, Gushan Dist., Kaohsiung City (22°38.952′N, 120°16.128′ E, 156m), one female (no. 388–1) from Macaranga tanarius (Euphorbiaceae), 11.iii.2010, J. R. Liao & S. W. Kong (NTU); Liugui Dist., Kaohsiung City (22°55.785′N, 120°39.148′E, 224m), one female (no. 942–6) from Bauhinia variegate (Fabaceae), 20.xi.2010, J. R. Liao (NTU).
Distribution. Asia: China (Fujian (Wu 1982), Guangdong (Chen et al. 1980; Wu 1982; Liang & Ke 1983), Guangxi (Wu 1982; Liang & Ke 1983), Hainan (Wu et al. 1997), Hong Kong (Ehara & Lee 1971), Hunan (Wu 1982), Jiangsu (Wu 1982; Liang & Ke 1983), Jiangxi (Wu 1982), Sichuan (Wu 1982; Liang & Ke 1983)), Taiwan (present study), Thailand (Ehara & Bhandhufalck 1977; Oliveira et al. 2012).
Remarks. Euseius nicholsi (Ehara & Lee) is reported for the first time for Taiwanese fauna. This species is widely distributed in Southern China, and also a dominated biological control agent for spider mites (e.g. Panonychus citri McGregor, Eotetranychus kankitus Ehara) in citrus orchard (Wu et al. 2009). However, only two specimens have been found in Southern Taiwan and the biological control potential of this species needs further investigations.
Liao et al. (2017a) reported that Taiwanese E. aizawai specimens had two morphological types on the dorsal shield (e.g. anterolateral dorsal shield reticulated and entire dorsal shield reticulated). After comparing holotypes of E. aizawai (from HUM), E. nicholsi (from NSMT), Chinese specimens of E. nicholsi (from GIABR), and discussing with Dr. Toyoshima (Pers. Comm., January 28, 2018), these Taiwanese specimens should belong to three different species, including E. aizawai, E. nicholsi, and E. sojaensis. E. aizawai differs from others in having anterolateral reticulation on dorsal shield (the remaining two species strongly reticulated on dorsal shield). E. nicholsi and E. sojaensis could be separated by the lengths of macrosetae. Additionally, Ehara & Lee (1971) reported E. nicholsi is characterized by hook-shaped metapodal platelets. However, we found two slender metapodal platelets are overlapping on the left side, but separated on right side of the holotype of E. nicholsi (NSMT AC-13078) (Figures 3).
FIGURES 4.
Euseius nicholsi Ehara & Lee, 1971, Female, A. dorsal shield, B. ventral idiosoma, C. chelicera, D. spermatheca.
FIGURES 5.
Euseius nicholsi Ehara & Lee, 1971, Female, legs A. leg I anterior view, B. leg II dorsal view, C. leg III anterodorsal view, D. leg IV anterior view.
Euseius sojaensis (Ehara, 1964)
(Figures 6–9)
Amblyseius sojaensis Ehara 1964: 381.
Amblyseius (Amblyseius) sojaensis—Ehara 1966: 24.
Amblyseius (Euseius) sojaensis—Ehara & Amano 1998: 42.
Euseius sojaensis—Moraes et al. 2004: 83.
Female (n=10).
A lightly sclerotized mite. Idiosomal setal pattern: 10A:9B/JV-3:ZV.
Dorsum (Figure 6A). Dorsal shield most surface strongly reticulated, 336 (314–366) long (j1–J5 level) and 233 (211–256) wide at level of j6, 221 (198–253) wide at level of S4; with five pairs of solenostomes (gd2, gd5, gd6, gd8, gd9), eight pairs of lyrifissures (id1,id1a, is1, idl3, idl4, idm3, idm5, idm6); muscle-marks (sigilla) visible on podosoma; length of setae: j1 29 (24–34), j3 25 (20–33), j4 9 (6–14), j5 8 (6–10), j6 9 (6–11), J2 11 (9–15), J5 6 (4–7), z2 18 (15–21), z4 15 (11–20), z5 9 (6–10), Z1 12 (10–13), Z4 11 (8–15), Z5 56 (52–63), s4 26 (22–34), S2 17 (14–21), S4 22 (19–26), S5 21 (16–28), r3 13 (9–18), R1 12 (8–13); All setae smooth, except Z5 slightly serrate.
Peritreme (Figure 6A). Peritreme over z2 level, peritrematic shield smooth, lightly sclerotized, with one pair of solenostomes (gd3), one pair of lyrifissures (id3).
Venter (Figure 6A). Sternal shield smooth, with projection of posterior margin, wider than long, 60 (48–66) long, 87 (77–95) wide at st3 level, with three pairs of setae st1 28 (20–32), st2 24 (17–32), st3 21 (17–25), and two pairs of lyrifissures (pst1, pst2). Exopodal shield at coxae I-IV. Metasternal platelets tear-shaped, with one pair metasternal setae, st4 19 (16–25), and one pair of lyrifissures (pst3). Genital shield smooth, 81 (75–87) wide at level of genital setae, with one pair of genital setae st5 21 (16–25). Distances between st1–st1 55 (49–59), st2–st2 63 (57–70), st3–st3 69 (60–74), st1–st3 59 (52–76), st5–st5 70 (63–77). Ventrianal shield smooth, vase-shaped, 97 (91–104) long, 50 (44–61) wide at level of ZV2, 74 (69–80) wide at level of anus; with three pairs of preanal setae, arranged in triangular pattern, JV1 23 (20–27), JV2 20 (16–25), ZV2 14 (12–16), solenostomes gv3 crescentic; Pa 11 (10–15), Pst 11 (8–13) on shield. Setae JV4 8 (5–11), JV5 31 (26–36), ZV1 17 (14–23), ZV3 9 (7–11) on interscutal membrane. All ventral setae smooth. Two pairs of metapodal platelets 19 (16–21) long, 5 (4–7) wide, 10 (8–11) long, 2 (2–3) wide.
Chelicera (Figure 6C). Movable digit 22 (21–25) long, with one tooth; fixed digit 23 (20–27) long, anterior half with four teeth, with pilus dentilis.
Spermatheca (Figure 6D). Calyx funnel-shaped, 12 (11–13) long, 7 (6–8) wide, minor duct visible.
Legs (Figure 7). Coxal formula 2-2-2-1. Chaetotaxy (femur to basitarsus): leg I, 2-3/1-2/2-1, 2-2/1-2/1-2, 2-2/1-2/1-2, 1-1/1-1; leg II, 2-3/2-2/0-1, 1-2/1-2/0-1, 1-1/1-2/1-1, 1-1/1-1; leg III, 1-2/1-1/0-1, 1-2/1-2/0-1, 1-1/1-2/1-1, 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 III (ad2) 27 (22–31), Sti III (ad) 22 (18–27), St III (d) 22 (16–30), Sge IV (ad2) 34 (26–37), Sti IV (ad) 30 (25–34) and St IV (d) 55 (48–63).
Male (n=5).
A lightly sclerotized mite. Idiosomal setal pattern: 10A:9B/JV-3, 4:ZV-1, 3.
Dorsum (Figure 8A). Dorsal shield most surface strongly reticulated, 249 (238–273) long (j1-J5 level) and 190 (176–200) wide at level of j6, 169 (152–189) wide at level of S4; with five pairs of solenostomes (gd2, gd5, gd6, gd8, gd9), five pairs of lyrifissures (id1, id1a, id4, is1, idl3, idl4); muscle-marks (sigilla) visible on podosoma; length of setae: j1 24 (22–28), j3 25 (21–28), j4 7 (6–8), j5 6 (5–8), j6 8 (5–10), J2 8 (6–11), J5 4 (4–5), z2 14 (10–17), z4 12 (8–16), z5 7 (6–9), Z1 9 (8–11), Z4 8 (7–11), Z5 45 (40–50), s4 24 (21–31), S2 15 (13–17), S4 18 (14–26), S5 19 (14–23), r3 11 (8–16), R1 12 (9–14); All setae smooth, except Z5 slightly serrate.
Peritreme (Figure 8A). Peritreme over z2 level, peritrematic shield smooth, lightly sclerotized, with one pair of solenostomes (gd3), one pair of lyrifissures (id3).
Venter (Figure 8B). Sternogenital shield smooth, slightly lateral reticulated, posterior margin almost straight, longer than wide, 115 (113–117) long, 78 (72–90) wide at level of st5, with five pairs of setae st1 19 (13–23), st2 19 (14–26), st3 19 (17–23), st4 13 (11–17), st5 15 (10–18), and three pairs of lyrifissures (pst1, pst2, pst3). Distances between st1–st1 53 (49–59), st2–st2 55 (46–61), st3– st3 55 (52–59), st4–st4 49 (48–52), st5–st5 36 (35–39), st1–st5 108 (103–112). Exopodal shield at coxae I-IV. Ventrianal shield subtriangular, slightly reticulated, 99 (87–114 long and 156 (145–177) wide at level of anterior corner, 68 (53–81) wide at level of anus, fused with peritrematic shield cingulum, with three pairs of pre-anal setae, arranged in triangular pattern, solenostome gv3 crscentic, JV1 17 (14–20), JV2 13 (10–18), ZV2 11 (8–16); Pa 8 (7–11), Pst 9 (6–12) on shield. Setae JV5 21 (17–29) on interscutal membrane. All ventral setae smooth.
Chelicera (Figure 8C). Movable digit 20 (18–21) long, with one tooth; fixed digit 21 (17–23) long, anterior half with three teeth, with pilus dentilis. Spermatodactyl U-shaped, shaft 25 (19–3) long, heel rounded, foot 11 (10–12) long, with expanded toe and lateral thorn-like projection.
Legs (Figure 9). Coxal formula 2-2-2-1. Chaetotaxy (femur to basitarsus): leg I, 2-3/1-2/2-1, 2-2/1-2/1-2, 2-2/1-2/1-2, 1-1/1-1; leg II, 2-3/2-2/0-1, 1-2/1-2/0-1, 1-1/1-2/1-1, 1-1/1-1; leg III, 1-2/1-1/0-1, 1-2/1-2/0-1, 1-1/1-2/1-1, 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 III (ad2) 21 (18–23), Sti III (ad) 19 (17–24), St III (d) 20 (17–25), Sge IV (ad2) 29 (25–32), Sti IV (ad) 25 (19–35) and St IV (d) 46 (40–53).
Specimens examined. TAIWAN: Anma Mountain, Heping District, Taichung City, eight females from unknown plant, 9.iv.1990, C.C. Ho (TARL); East Xue Trail, Heping District, Taichung City, one female from unknown plant, 29.xi.2006, C.C. Ho (TARL); Lishan, Helping District, Taichung City, five females one male from unknown plant, 1.xii.2006, C.C. Ho (TARL); Lishan, Helping District, Taichung City, one female from Morus australis (Moraceae), 1.xii.2006, C.C. Ho (TARL); Qingjing Farm, Ren'ai Township, Nantou County, one female from Pyrus communis (Rosaceae), 5.xii.2006, S.C. Chang (TARL); Formosan Aboriginal Culture Village, Yuchi Township, Nantou County, one female one male from Prunus serrulata (Rosaceae), 15.v.2007, C.C. Ho (TARL); Huanshan, Heping District, Taichung City, three females one male from Prunus sp. (Rosaceae), 20.x.2009, C.C. Ho (TARL); Huanshan, Heping District, Taichung City, three females from Prunus salicina (Rosaceae), 20.x.2009, C.C. Ho (TARL); Huanshan, Heping District, Taichung City, two females from unknown plant, 20.x.2009, C.C. Ho (TARL); Shigilan Suspension Bridge, Heping District, Taichung City, four females one male from unknown plant, 21.x.2009, C.C. Ho (TARL); Wanfeng Village, Wufeng District, Taichung City, four females two males from bamboo (Poaceae), 9.iii.2010, C.C. Ho (TARL); Lushan, Ren'ai Township, Nantou County, one female from Calocedrus formosana (Cupressaceae), 22.xi.2010, C.C. Ho (TARL); Xuejian, Tai'an Township, Miaoli County, two females from unknown plant, 23.iii.2012, C.C. Ho (TARL); Maokong, Wenshan District, Taipei City (24°58.062′ N, 121°35.332′ E, 313m), two females (no. 584–1, 2) from Cocos nucifera (Arecaceae), 9.vi.2010, J.R. Liao & A.K. Dubey (NTU); Maokong, Wenshan District, Taipei City (24°58.062′ N, 121°35.332′ E, 313m), six females (574–1, 2, 3, 4, 5, 6) from unknown plant, 9.vi.2010, J.R. Liao & A.K. Dubey (NTU); Paomagudao, Jiaoxi Township, Yilan County (24°50.276′ N, 121°46.346′ E, 147m), one female (no. 1113–1) from Carica papaya (Caricaceae), 9.ii.2011, J.R. Liao (NTU); Xiouluan Road, Jianshi Township, Hsinchu County (24°38.252′ N, 121°16.430′ E, 1010m), one female (no. 1268′1) from Dendrocalamus latiflorus (Poaceae), 17.iv.2014, J.R. Liao (NTU); Xiakelo Historic Trail, Jianshi Township, Hsinchu County (24°35.346′ N, 121°15.273′ E, 1260m), one female (no. 1283–2) from Machilus sp. (Lauraceae), 17.iv.2014, J.R. Liao (NTU); TsaoPingTou, Jianshi Township, Hsinchu County (23°33.447′ N, 120°52.515′ E, 1095m), two females (no. 1292–1, 2) from Prunus campanulata (Rosaceae), 24.iv.2014, J.R. Liao (NTU); TsaoPingTou, Jianshi Township, Hsinchu County (23°33.447′ N, 120°52.515′ E, 1095m), two females (no. 1293–1, 2) from Machilus zuihensis (Lauraceae), 24.iv.2014, J.R. Liao (NTU); Shenshan, Wutai Township, Pingtung County (22°44.986′ N, 120°43.640′ E, 708m), one female (no. 1471–1) from Pachira aquatica (Malvaceae), 25.iv.2014, J.R. Liao (NTU); Jiangshuying Old trail, Wutai Township, Pingtung County (22°24.459′ N, 120°45.404′ E, 1496m), one female (no. 1461–1) from Turpinia formosana (Staphyleaceae), 24.iv.2014, J.R. Liao (NTU); Shihmen Farm, Longtan District, Taoyuan City (24°48.876′ N, 121°12.897′ E, 544m), three females (no. 1513–1, 2, 3) from Morus sp. (Moraceae), 30.v.2015, J.R. Liao (NTU); Jianshi Township, Hsinchu County (24°41.896′N, 121°13.120′ E, 376m), three females (no. 1585–1, 4, 5) from Bauhinia variegata (Fabaceae), 31.xii.2015, J.R. Liao (NTU); Jianshi Township, Hsinchu County (24°40.122′ N, 121°16.512′ E, 1185m), three females (no. 1591–2, 7, 9) from Debregeasia orientalis (Urticaceae), 31.xii.2015, J.R. Liao (NTU).
Distribution. Asia: Japan (Ehara 1964; Ohno et al. 2012), Taiwan (present study).
Remarks. Euseius sojaensis (Ehara) is reported for the first time for Taiwanese fauna.
This species is distributed in Japan (e.g. Honshu, Shikoku, Kyushu, and Okinawa islands) (Ehara 1964; Ohno et al. 2012; Toyoshima et al. 2018). Shibao et al. (2004) reported E. sojaensis has potential to be a predator for yellow tea thrips (Scirtothrips dorsalis Hood) in Japanese vineyards. This species is widely distributed in Taiwan. It may have biological control potential in the field, but needs further studies.
As previously mentioned, E. aizawai specimens in Liao et al. (2017a) should be separated to three different species. E. sojaensis could be identified by strongly reticulation on most part of the dorsal shield and 5 pairs of solenostomes on the dorsal shield.
FIGURES 6.
Euseius sojaensis Ehara, 1964, Female, A. dorsal shield, B. ventral idiosoma, C. chelicera, D. spermatheca.
FIGURES 7.
Euseius sojaensis Ehara, 1964, Female, legs A. leg I posterior view, B. leg II posterior view, C. leg III dorsal view, D. leg IV anterior view.
FIGURES 8.
Euseius sojaensis Ehara, 1964, Male, A. Dorsal shield; B. Ventral idiosoma; C. Chelicera and spermatodactyl.
A revised identification key to females of Euseius species from Taiwan
1. Dorsal shield length relatively smaller, c.a. 250 µm; JV1 and JV2 on normal position; only leg IV with macrosetae 2
- Dorsal shield length relatively larger, c.a. 350 µm; JV1 and JV2 arranged in tangential row; leg III and leg IV with macrosetae 3
2. Calyx of spermatheca long and narrow funnel-shaped, atrium sac-shaped with thick walls circellatus (Wu & Li, 1983)
- Calyx of spermatheca horn-shaped, atrium c-shaped with a pair of petal-shaped structure macaranga Liao & Ho, 2017
3. Dorsal setae j1 and Z5 conspicuously longer, others minute; calyx of spermatheca tubular 4
- Dorsal setae j1 and Z5 not conspicuously longer, remaining setae not minute; calyx of spermatheca funnel or cup-shaped 5
4. Dorsal shield reticulated anterolaterally ovalis (Evans, 1953)
- Dorsal shield strongly reticulated except for central podosoma paraovalis Liao & Ho, 2017
5. Calyx of spermatheca short cup-shaped oolong sp. nov.
- Calyx of spermatheca relative longer, funnel shaped, flaring distally 6
6. Dorsal shield most surface reticulated 7
- Dorsal shield mostly smooth except reticulated in anterolateral region 8
7. St IV longer than 60 µm nicholsi (Ehara & Lee, 1971)
- St IV c.a. 50 µm sojaensis (Ehara, 1964)
8. Dorsal shield with six pairs of solenostomes aizawai (Ehara & Bhandhufalck, 1977)
- Dorsal shield with five pairs of solenostomes daluensis Liao & Ho, 2017
Tribe Indoseiulini Ehara and Amano
Gynaseius Wainstein
Gynaseius santosoi (Ehara, 2005)
(Figures 10–11)
Indoseiulus santosoi Ehara 2005: 36.
Female (three specimen).
A lightly sclerotized mite. Idiosomal setal pattern: 10A:8C/JV-3:ZV.
Dorsum (Figure 10A). Dorsal shield smooth; 382 (358–406) long (j1–J5 level) and 251 (247–255) wide at level of j6, 230 (230–231) wide at level of S4; seven pairs of solenostomes on dorsal shield, (gd1, gd2, gd4, gd5, gd6, gd8, gd9), nine pairs of lyrifissures (id2,id3, id4, is1, idm3, idx, idm4, idl4, idm6); muscle-marks (sigilla) visible on podosoma; length of setae: j1 28 (27–30), j3 15 (15–15), j4 7 (7–8), j5 7 (6–8), j6 7 (6–8), J2 9 (8–10), J5 6 (6–7), z2 10 (9–11), z4 8 (6–9), z5 7 (4–11), Z1 9 (7–11), Z4 15 (10–18), Z5 17 (16–19), s4 13 (13–14), S2 12 (11–13), S5 7 (5–9), r3 9 (6–11), R1 8 (7–9). All setae smooth.
Peritreme (Figure 10A). Peritreme extending beyond seta j3; peritrematic shield not being fused with dorsal shield anteriorly, with one pair of solenostomes (gd3), one pair of lyrifissures (id3).
Venter (Figure 10B). Sternal shield smooth, posterior margin slightly concave, much wider than long, 80 (75–86) long, 97 (90–106) wide, with three pairs of setae st1 34 (31–36), st2 31 (28–33), st3 28 (21–33), and two pairs of lyrifissures (pst1, pst2). Exopodal shield at coxae II–IV. Metasternal platelets tear-shaped, with one pair metasternal setae, st4 26 (23–29), with one pair of lyrifissuress (pst3). Genital shield smooth, with one pair of genital setae st5 33 (28–35), 98 (95–101) wide at level of genital setae. Distances between st1-st1 64 (56–72), st2-st2 67 (59–75), st3-st3 76 (66–82), st1-st3 70 (58–81), st5-st5 86 (77–90). Ventrianal shield margin invisible; with three pairs of pre-anal setae, JV1 25 (22–28), JV2 24 (22–26), ZV2 21 (21–23), solenostomes gv3 crescentic; Pa 12 (11–14), Pst 18 (17–20) on shield. Setae JV4 19 (16–20), JV5 44 (40–46), ZV1 24 (20–27), ZV3 19(19–20) on interscutal membrane. All ventral setae smooth. One pair of metapodal plates 21 (20–22) long, 5 (4–6) wide.
Chelicera (Figure 10C). Movable digit 31 (30–33) long, with one tooth; fixed digit 28 (25–30) long, anterior half with three teeth, with pilus dentilis.
Spermatheca (Figure 10D). Calyx cup-shaped, 4 (3–5) long, 8 (7–10) wide, atrium incorporated without neck, with a thin major duct, minor duct visible.
Legs (Figures 11). Coxal formula 2-2-2-1. Chaetotaxy (femur to basitarsus): leg I, 2-3/1-2/2-2, 1-2/1-1/2-1, 1-2/1-2/2-2, 1-1/1-1; leg II, 2-3/2-2/0-1, 1-2/1-2/0-1, 1-1/1-2/1-1, 1-1/1-1; leg III, 1-2/1-1/0-1, 1-2/1-2/0-1, 1-1/1-2/1-1, 1-1/1-1; leg IV, 1-2/1-1/0-1, 1-2/0-2/1-1, 1-1/0-2/1-1, 1-1/1-1. Macrosetae: Sge I (pd1) 28 (27–31), Sge II (pd2) 32 (30–35), Sge III (ad2) 41 (40–43), Sti III (ad) 35 (33–37), St III (d) 23 (21–27), Sge IV (ad2) 59 (55–62), Sti IV (ad) 44 (42–49) and St IV (d) 54 (51–55).
Specimens examined. TAIWAN: Lanyu Island, Taitung County (22°00.881′ N, 121°33.970′ E, 39m), one female (no. 462–1) from Morus alba (Moraceae), 4.iv.2010, J. R. Liao & C. C. Ho (NTU); Lanyu Island, Taitung County (22°03.846′ N, 121°30.655′ E, 21m), one female (no. 1646–2) from Morus alba (Moraceae), 14.iv.2016, H. Y. Lin (NCHU); Cihou Fort, Qijin District, Kaohsiung City (22°36.933′ N, 120°15.917′ E, 13m), one female (no. 2016–2) from Macaranga tanarius (Euphorbiaceae), 22.i.2017, J. R. Liao & H. C. Lee (NMNS).
Distribution. Asia: Indonesia (Java (Ehara, 2005), Taiwan (Kaohsiung, Lanyu Island (present study)).
Remarks. Gynaseius santosoi (Ehara) is reported for the first time for Taiwanese fauna. Ehara (2005) described this species based on a single female specimen from a fabaceous climbing plant from Indonesia. The present study found several differences with the original description: leg III with three macrosetae (two in Ehara (2005)), one macroseta on Ge I (two macrosetae in Ehara (2005)), posterior margin of sternal shield concave (indented in Ehara (2005)).
The Lanyu specimens were collected from the habitat plants when Neoseiulus longispinosus and Eotetranychus suginamensis occured. However, futher observation is still needed for feeding habit and lifestyle of this species.
FIGURES 9.
Euseius sojaensis Ehara, 1964, Male, legs A. leg I dorsal view, B. leg II dorsal view, C. leg III anterodorsal view, D. leg IV dorsal view.
FIGURES 10.
Gynaseius santosoi Ehara, 2005, Female, A. dorsal shield, B. ventral idiosoma, C. chelicera, D. spermatheca.
FIGURES 11.
Gynaseius santosoi Ehara, 2005, Female, A. leg I anterior view, B. leg II posterior view, C. leg III posterior view, D. leg IV posterior view.
Key to females of Gynaseius species of the world
1. Seta r3 on dorsal shield 2
- Seta r3 on integument 3
2. Sge IV > St IV > Sti IV semiiregularis (Schicha & Corpuz-Raros, 1992)
- Sti IV > Sge IV > St IV herbridensis (McMurtry & Moraes, 1984)
3. Setae S2, S4 present; only one macroseta on leg IV larum El-Banhawy & Knapp, 2011
- At least one of setae S2, S4 present 4
4. Seta S2 occupy a position far behind its normal position; movable digits of chelicera without teeth christinae (Schicha, 1981)
- Seta S2 in normal position; movable digits of chelicera at least with one teeth 5
5. Spermatheca calyx dish-shaped irregularis (Evans, 1953)
- Spermatheca calyx cup-shaped, or tubular 6
6. Ventrianal shield vase-shaped or pentagonal 7
- Margin of ventrianal shield invisible 8
7. Ventrianal shield vase-shaped, spermatheca calyx cup-shaped duanensis (Liang & Zeng, 1992)
- Ventraianl shield pentagoanl, spermatheca short tube, coiled ghaiae (Denmark & Kolodochka, 1993)
8. Movable digits of chelicera with one tooth 9
- Movable digits of chelicera with three teeth 10
9. Sge IV > Sti IV > St IV eharai (Gupta, 1986)
- Sge IV > St IV > Sti IV santtosoi (Ehara, 2005)
10. Dorsal shield with seven pairs of solenostomes liturivorus (Ehara, 1982)
- Dorsal shield with five pairs of solenostomes on dorsal shield ricini (Ghai & Menon, 1969)
Acknowledgements
We thank to Y. T. Hsu (TTDARES, Taiwan) for cooperation in Lanyu Island collection, W. N. Wu (GIABR, China) for arrangement of visiting GIABR and also provided valuable suggestions to first author, to İ. Döker (CU, Turkey), A. K. Dubey (ZSI, India), Y. Hsiao (CSIRO & ANU, Australia), J. F. Hsieh (NTU, Taiwan), S. F. Lin (NCHU, Taiwan), M. Ma (SXAU, China), S. Toyoshima (NARO, Japan) for suggestions. Thanks are extended to anonymous reviewers for help in improving the manuscript, to D. Watterson and P. Bensley (Wallace Academic Editing) for English editing of the draft. Thank H. Ohara and H. Kajihara (HUM, Japan), H. Ono (NSMT, Japan), L.A. Corpuz-Raros and J. Naredo (UPLB-MNH) for borrowing type specimens for comparison. The study is supported by a grant (MOST105-2621-B-002-002-MY3) from the Ministry of Science and Technology, Taiwan.
