Eotetranychus sexmaculatus (Riley 1890)

Beard, Jennifer J., Beaulieu, Frédéric, Knee, Wayne & Gotoh, Tetsuo, 2024, The six-spotted spider mite, Eotetranychus sexmaculatus (Riley) (Trombidiformes: Tetranychidae) in Australia, New Zealand, Japan and USA: a revised morphological and molecular-based concept, synonyms, and related species, Zootaxa 5432 (3), pp. 349-378 : 358-360

Eotetranychus sexmaculatus (Riley 1890)

( Figs 4–14 )

Tetranychus 6-maculatus Riley 1890 : 226.

Tetranychus sexmaculatus Riley. — Banks 1900: 75; McGregor 1919: 659; McGregor 1950: 301.

Eotetranychus sexmaculatus (Riley) .— Pritchard & Baker 1955: 202; Ehara 1956: 142; Ehara 1966: 8; Gupta & Gupta 1994: 81.

Eotetranychus asiaticus Ehara 1966: 8 . Synonymy by Ehara 1973: 8.

AUSTRALIA (total examined: 30 females, 18 males): 5 F, 2 M, ex avocado leaves Persea americana ( Lauraceae ), Pemberton, Western Australia, on seedlings imported from Birdwood Nursery, Woombye, Queensland, 16.viii.1986, S. Learmonth (det. E.W. Baker 1986); 1 M, ex avocado leaves, Pemberton, Western Australia, on seedlings imported from Birdwood Nursery, Woombye, Queensland, 4.ix.1986, G. Waite & D. Smith ( USNM); 8 F, 4 M, ex avocado leaves, Birdwood Nursery, Woombye, Queensland, 4.ix.1986, G. Waite & D. Smith (det. E.W. Baker 1986); 5 F, 1 M, ex avocado leaves, Airville, 15 km southwest Ayr, Queensland, 10.ix.1986, I. Kaye & J. Rahder; 3 F, 4 M, ex grape leaves Vitis vinifera ( Vitaceae ), Western Australia, 6.vi.2006, S. Learmonth; 2 F, 2 M, ex grape leaves V. vinifera, Resolution Vineyard , 4 Sunnybanks Rd, Middleton, Tasmania, 17.iii.2015, P. Brown; 7 F, 4 M, ex avocado leaves, Pemberton, Western Australia, 10.iv.2018, S. Learmonth; 6 F, 4 M, ex avocado leaves, Pemberton, Western Australia, 03.ix.2021, A. Mathews. Unless otherwise indicated, all material in QM.

CHINA: 5 F, 3 M, ex kiwifruit leaves Actinidia deliciosa ( Actinidiaceae ), collected in quarantine in New Zealand, det. S.J. Bennet 10.i.2007 ( PHEL Ref. 09/2007/75) ( NZAC).

TAIWAN: 4 F, 1 M, ex Citrus (J. Burman) (jun. syn. “ C. grandis ” (L.) indicated on slide), Taipei, 18.vi.1951, T.C. Maa (Lot #51-7165; CNC - CNC 396823, CNC 396824).

JAPAN (total examined: 19 females, 14 males): 11 F, 6 M, ex Ficus erecta Thunb. ( Moraceae ), Tomigusuku, Okinawa, 22.iv.1966, K. Miyara ( HUM — E. asiaticus paratypes); 4 F, 4 M, ex culture, originally collected from Ficus virgata Reinw. Ex Blume, Tomigusuku , Okinawa, 26°09′29 ʺN 127°39′31 ʺE, 20.x.2021, T. Gotoh ( QM); 4 F, 4 M, ex culture, originally collected from F. virgata, Naha , Okinawa, 26°13′36 ʺN 127°42′50 ʺE, 20.x.2021, T. Gotoh ( QM).

NEW ZEALAND (total examined: 13 females, 17 males): 2 F, 1 M, on black locust leaves Robinia pseudoacacia ( Fabaceae ), Te Kauwhata, 26.ii.1963, D.C.M. Manson; 4 F, 8 M, on Palamino grape leaves, Te Kauwhata, 19.iii.1965, P.F. Hitchcock; 2 F, 5 M, on grape leaves, Henderson, 31.iii.1965, A. McKissock; 2 M, ex grape leaves, Corbans Vineyard, Henderson, 30.iii.1967, from P.D.D.; 5 F, 1 M, ex avocado leaves, B.P. No. 3 Road, Te Puke, Grahame Ross Farm, 19.iii.1984, P.A. Brown; 3 F, 3 M, ex Hass avocado leaves ( P. americana ), Poroti, 08.iv.2021, 35°44’22.5882” S 174°08’38.9034” E, E. Barraclough ( QM); 3 F, 3 M, ex Hass avocado leaves, Te Puke, 37°49’15.9312” S 176°18’58.6548” E, 14.iv.2021, E. Barraclough ( QM). Unless otherwise indicated, all material in NZAC.

UNITED STATES OF AMERICA (total examined: 32 females, 36 males): USNM:1 M, ex orange Citrus sinensis ( Rutaceae ), Eloise Loop, Florida, 17.xi.1949, L.C. Knorr (#5874, Lot 50-1); 1 M, ex lemon, Ventura, California, 20. x.1951, L.R. Jeppson; 1 F, 1 M, ex avocado ( Lauraceae ), Morrow [Morro] Bay, California, 3.iv.1986, J.M. McMurtry. FSCA: 1 F, 2 M, ex Citrus X paradisi, Sanford, Florida, 29.iv.1980, T.L. Kipp; 1 F, 2 M, ex Citrus sinensis, Immokalee , Florida, 21.i.1981, K. Delate; 1 F, 1 M, ex Citrus X paradisi, Miami, Florida, 20.iv.1981, N. Focaracci; 1 F, 3 M, ex Citrus limon, N. W. Miami, Florida, 13.ix.1988, Vadaie & Storch; 2 F, 2 M, ex Citrus aurantium, DeLand, Volusia County , Florida, 12.vii.1995, J. Beckwith; 1 F, 2 M, 2 deutonymphs, 2 protonymphs, Citrus X paradisi, Mims, Brevard County, Florida, 22.iv.1997, K. Garrett-Kraus (E1997-001660-001); 4 F, 3 M, ex Citrus sp. , Dunnellon, Citrus County, 17.v.2006, S. White (E-2006-2785); 4 F, 1 M, ex Citrus sp. , Trenton, Gilchrist County, Florida, 3.v.2013, P. Carbon (E-2013-2915); 1 F, 2 M, ex Citrus sp. , Live Oak, Suwannee County, Florida, 10.i.2014, W. Wayne Bailey (E-2014-152); 5 F, 5 M, ex X Citroncirus sp. ( Rutaceae ), Gainesville, Alachua County, Florida, 12.xii.2014, P. Carbon (E-2014-8144); 2 F, 1 M, ex Citrus reticulata, Waldo, Alachua County , Florida, 28.ii.2019, S. Hart (E-2019-831). UHIM: 1 M, ex avocado leaves, Waipio, Oahu, Hawai’i, 10.viii.1955, F.H. Haramoto ( UHIM 2013.16574); 2 F, 1 M, ex leaves of flowering plum, Kalihi, Honolulu, Hawai’i, 20.vi.1960, F.H. Haramoto ( UHIM 2013.16570, UHIM 2013.16575); 3 F, 2 M, ex guava leaves Psidium guajava ( Myrtaceae ), Manoa, Oahu, Hawai’i, 23.viii.1965, F.H. Haramoto ( UHIM 2013.16565-66, UHIM 2013.16573); 1 F, 2 M, ex guava leaves, Waimanala, Hawai’i, 15.vii.1968, H. Nakasane ( UHIM 2013.16568, UHIM 2013.16571-72); 2 F, 3 M, ex sacred bamboo leaves Nandina sp. ( Berberidaceae ), Honolulu, Oahu, Hawai’i, 18.ii.1972, M. Topham ( UHIM 2013.16567, UHIM 2013.16569, UHIM 2013.16576).

Diagnosis. Both sexes: Dorsal setae long, mostly 60–90 μm (in female) except h1 usually shorter (~40–60). Opisthosomal striae generally transverse (becoming longitudinal in lateral regions), with small rounded lobes in female. Peritremes with a short distal bend, resembling a golf club (when short) to a field hockey stick (when slightly longer) in shape. Female: Palptarsus with stout spinneret suζ, about 1.3–1.7 x as long (5.5–6.5 μm) as wide (3.5–4.5 μm); pregenital region with longitudinal and entire (uninterrupted) striae, extending a short distance onto anterior region of genital flap to level with setae g1 and becoming strongly oblique lateral to g1; followed posteriorly by a band of transverse striae in middle region of genital flap, and a narrow band of longitudinal and or arching striae along posterior margin of genital flap. Tarsus I usually with five tactile setae proximal to proximal duplex setae, including three dorsolaterally (l′1, lʺ1, l′2) (usually four tactile setae proximal in male, including two dorsolaterally); tibia II with eight setae; tibia IV with seven setae; femur IV with only three setae, lacking seta d, seta l′1 inserted midway on dorsolateral aspect. Male: Aedeagus more or less linear, abruptly narrowed and bent posteroventrally near midway, forming a narrow weakly tapering (almost parallel-sided) finger, ending in an obliquely truncate tip (a minute ventral point sometimes visible on the tip). Palptarsus with small spinneret suζ, approximately 1.0–1.3 x as long (1.5–1.9 μm) as wide (1.3–1.7 μm).

Figures

FIGURE 4. Eotetranychus sexmaculatus. Female habitus; dorsal idiosomal setae labelled; specimen from Citrus sp. in Florida, USA.

FIGURE 5. Eotetranychus sexmaculatus (A–H) and E. queenslandicus (I). Genital and pregenital area of specimens—(A–C) from Citrus spp. and X Citroncirus sp. in Florida, USA (A: Alachua County, B: Dunnellon Co., C: Suwannee Co.); (D–F) from grape and avocado in southwestern Western Australia (D: grape, E–F: avocado); (G) from Citrus sp. in Taiwan; (H) of E. asiaticus paratype from Ficus sp. in Okinawa, Japan; (I) of E. queenslandicus paratype from Codaeium variegatum in Freshwater, Queensland, Australia. Legend: FL—Florida (USA), WA—Western Australia, CA—California (USA), TA—Taiwan, PT—paratype

FIGURE 6. Eotetranychus sexmaculatus. (A) female palp and (B) male palp, with photos showing slight variation of dimension of tarsal spinneret; (C) variation in peritremes.

FIGURE 7. Eotetranychus sexmaculatus. Female leg I, tibia and tarsus (only tibia in D); dorsal aspect (A) and ventral aspect (B– D). Illustrations are based on specimens from Citrus sp. in Florida and from Ficus virgata in Okinawa, and are representative of all populations studied. Red arrow indicates seta l′2 that is not present in many other Tetranychinae (including the representative Tetranychus sp. illustrated in Lindquist (1985:17)).

FIGURE 8. Eotetranychus sexmaculatus. Female leg II, tibia and tarsus (A–B) and trochanter, femur and genu (C); dorsal aspect (A, C) and ventral aspect (B). Illustrations are based on specimens from Citrus sp. in Florida, and are representative of all populations studied. Red arrow indicates seta lʺ1 that is not present in many other Tetranychinae (including the representative Tetranychus sp. illustrated in Lindquist (1985:17)).

FIGURE 9. Eotetranychus sexmaculatus. Female leg III, dorsal (A) and ventral aspect (B) of tibia and tarsus, and leg IV, dorsal aspect of trochanter, femur and genu (C). Illustrations are based on specimens from Citrus sp. in Florida, and are representative of all populations studied. Red arrow indicates seta vʺ1 that is not present on tarsus III in many other Tetranychinae (including the representative Tetranychus sp. illustrated in Lindquist (1985:17)).

FIGURE 10. Eotetranychus sexmaculatus. Ambulacra, female I (A) and IV (B), male I (C) and IV (D) (red arrows indicate the fine dorsal and ventral hairs flanking the middle thickened proximoventral hair).

FIGURE 11. Eotetranychus sexmaculatus (including E. asiaticus) (A–N), E. spanius (possible synonym of E. sexmaculatus) (O) and E. queenslandicus* (P–R). Presentation of variation of aedeagus in lateral view (A–C, E–H, K–L, O), in dorsolateral view (J, M), and in mostly dorsal view (D, I, N). *It is unclear whether the aedeagi of E. queenslandicus paratypes are in a dorsolateral or lateral view. Host plants: (A–B), (D–E) Citrus sp.; (C) X Citroncirus sp.; (F–I) avocado; (K) Ficus erecta; (L–N) Ficus virgata; (O) Psidium guajava; (P–R) Codaeium variegatum. Legend: FL—Florida (USA), WA—Western Australia, CA—California (USA), TA—Taiwan; PT—paratype; HT—holotype.

FIGURE 12. Eotetranychus sexmaculatus. Measurements for various sections of the aedeagus—(a) length of (entire) dorsal margin, (b) length of ventral margin, (c) length of narrow posterior (apical) section, (d) width of narrow posterior (apical) section measured at midpoint, (e) maximal (vertical) width of shaft.

FIGURE 13. Eotetranychus sexmaculatus. Male leg I, tibia and tarsus (dorsal to slightly lateral aspect). Illustration is based on specimens from Citrus sp. in Florida, and are representative of all populations studied.

FIGURE 14. Eotetranychus sexmaculatus. (A) Protonymph leg I, tibia and tarsus (in dorsal aspect); (B) protonymph leg IV (in adaxial to dorsal aspect); (C) deutonymph leg I, tibia and tarsus (in dorsal aspect); (D) deutonymph leg IV (in abaxial aspect).