Paroxythrips podocarpi, Masumoto, Masami & Okajima, Shûji, 2017

Masumoto, Masami & Okajima, Shûji, 2017, Paroxythrips gen. n. (Thysanoptera, Thripidae), associated with the gymnosperm order Araucariales in Japan and Australia, Zootaxa 4236 (2), pp. 343-350 : 345-348

Paroxythrips podocarpi sp. n.

( Figs 4–22 )

Female macroptera ( Fig. 4 ). Distended body length about 1.2 mm. Body almost uniformly yellow, pronotum sometimes with slightly shaded markings; antennal segment I yellow, II yellow or weakly shaded, III–VIII brown but III often slightly paler; fore wings almost uniformly pale brown with clavus slightly darker; all legs yellow. Prominent body setae brown. Head slightly prolonged forward, about 0.7 times as long as wide, with transverse striae behind row of postocular setae, cheeks straight ( Fig. 6 ). Compound eyes with four weakly pigmented facets ventro-laterally. Ocellar setae pair III situated at or slightly behind tangent line of posterior margin of hind ocelli, slightly longer than longitudinal diameter of hind ocelli. Postocular setae arranged in transverse straight line. Antennal segment II without microtrichia, III to IV rounded at each side and without apical neck, IV to V pedicelate, VI straight at each side and apical half tapering, VI longest ( Fig. 7 ). Antennal segments I–VIII length/ width ratio as follows: 0.7–0.8, 1.2–1.3, 2.0–2.2, 2.2–2.3, 1.7–1.8, 2.5, 1.0–1.2, 2.0–2.5. Pronotum about 0.7 times as long as wide, almost smooth medially but with a few transverse sculpture lines near anterior and posterior margins, with 16–17 discal setae, eight setae not longer than discal setae on anterior margin; posteromarginal setae 4 pairs; posteroangular setae 0.2–0.3 times as long as median length of pronotum ( Fig. 6 ). Mesonotum with anastomosing striae throughout; paired CPS present anteromedially. Metascutum with median pair of setae 0.2–0.3 times as long as metascutal median length; CPS absent ( Fig. 8 ). Fore wing costal vein with 20–26 setae, second vein with 6–9 setae. Abdominal tergites II–VII sculptured with anastomosing striae laterally, smooth between median CPS ( Fig. 9 ); tergites VI–VIII with S4 setae reduced to minute; tergite VIII with distinct posteromarginal craspeda lacking posteromarginal comb and convex at middle ( Fig. 10 ); tergite IX with both anterior and posterior pairs of CPS, ms3 slightly shorter than MD setae; sternite VII with S1 and S2 setae much in front of posterior margin ( Fig. 11 ). Ovipositor 1.6–1.7 times as long as pronotal median length.

Measurements (holotype female in microns). Distended body length 1100. Head length 86, width across cheeks 123; compound dorsal length 50, width 35; ocellar setae pair III length 1 5–18. Pronotal median length 103, width 143; posteroangular setae length 27. Metascutal median length 55, median setae length 15. Fore wing length 470, width at middle 35. Abdominal tergite IX median length 56; MD setae length 38–40 tergite X length 44. Ovipositor length 160. Antennal segments I to VIII length (width) as follows: 19 (26), 30 (23), 33 (16), 35 (16), 28 (15), 41 (16), 8 (8), 13 (5).

Male macroptera ( Fig. 5 ). General structure as in female. Abdominal tergite IX with large posteromarginal craspeda, S1 and S2 setae subequal in length and usually arranged in transverse line, and situated at the posterior margin or slightly displaced to craspeda ( Fig. 12 ); sternal pore plates oval and 3.5–6 µm wide ( Fig. 13 ).

Second instar larva. Distended body length about 1.0 mm. Body uniformly yellow ( Fig. 14 ); head with three brown markings, a large marking anteromedially, a small one on posteroinner side of each eye, rarely small ones at base of dorsal surface of head ( Fig. 15 ); pronotum rarely with two small brown markings; abdominal tergite IX usually a transverse dark are at posterior margin not exceed S1 setae; tergite X with a dark area behind CPS ( Fig. 21 ). All body setae small and acute at apices. Head with 4 pairs of small setae dorsally, D3 setae slightly longer than others. Antennae 7-segmented, segments III with annulations but no microtrichia, IV with microtrichia and a long inner sensorium exceed apex of VI, and a small outer sensorium, VI with outer sensorium reaching to apex of VII ( Fig. 16 ). Pronotum with a pair of large smooth areas medially surrounded D1–D5 and D7 setae, sclerotised area at middle weak; setae subequal to length of setae on head, apices acute ( Fig. 15 ). Meso- and metanota covered with longitudinal plaques having no microtrichia, each with a pair of small smooth areas medially, mesothoracic spiracle large and with numerous pores but no distinct facets ( Figs 17, 18 ). Abdominal tergites with all setae acute or blunt at apices, at least not expanded, with about 7 transverse rows of longitudinal plaques, but fewer on IX to X, plaques with microtrichia on VIII to X, but very weak on VIII ( Figs 20, 21 ); tergites II and VIII with spiracles large and transverse having numerous pores but no facets ( Fig 19 ); tergites III–VIII with 3 pairs of setae slightly longer at posterior segments, D3 setae longest on VI–VIII; tergite VIII with about 13 small teeth along posterior margin; tergite IX with D1 setae slightly shorter than D2 setae, and subequal length to D1 setae on tergite X, D3 setae short and situated anterolaterally, distance of median CPS same as interval D1 setae; sternites covered with 8–10 transverse rows of longitudinal plaques having microtrichia posterior margin; sternites III–VIII with three pairs of setae acute at apices, longer at posterior segments ( Fig. 22 ).

Type series. Holotype female, Japan, Honshu , Hiroshima Pref . , Higashi-hiroshima City, Akitsu-cho, Mitsu, on leaf of Podocarpus macrophyllus [ Podocarpaceae ], 17.x.2014, W. Ashihara, T. Arai & M. Toyama .

Paratypes: Japan, Honshu : 4 females, same data as holotype . 1 female and 1male, same place and plant as holotype, 2.x.2014. 10 females, same place and plant as holotype, 30.x.2014. Hiroshima Pref., Higashi-hiroshima City, Akitsu-cho , 16 females, 16 males on young leaves of P. macrophyllus , 19.vi.2011 . Shizuoka Pref. , Shizuoka City, Shimizu-ku, Komagonishi , 12 females, 4 males on young leaves of P. macrophyllus , 24.ix.2015 . Shikoku: Ehime Pref., Matsuyama City, Shimoidai-machi , 3 females, 2 males on young leaves of P. macrophyllus , 17.ix.2011 . Kochi Pref., Kochi City, Asakura , 12 females, 9 males on young leaves of P. macrophyllus , 8.x.2015 . Kochi Pref., Nankoku City, Hataeda , 5 females, 2 males on young leaves of P. macrophyllus , 9.x.2015 . Kyushu: Tanegashima-Is., Nakatane-cho , 8 females, 3 males on young leaves of P. macrophyllus , 30.viii.2011 . Ryukyus: Amami-ohshima Is., Sumiyo-cho , 4 females, 1 male on young leaves of P. macrophyllus , 12.vii.2012 . Kikai-jima Is., Kikai-cho , 7 females, 2 males on young leaves of P. macrophyllus , 3.ix.2011 . Okinawa-hontou Is., Tomigusuku-shi, Noha , 1 female, 1male on young leaves of P. macrophyllus , 3.ix.2011. The holotype and most paratypes are deposited in TUA.

Non-paratypic specimens. Japan, Honshu: Hiroshima Pref., Higashi-hiroshima City , Akitsu-cho , 3 second instar larvae on young leaves of P. macrophyllus , 19.vi.2011 [TUA]. Shikoku : Kochi Pref., Nankoku City, Hataeda , 2 second instar larvae on young leaves of P. macrophyllus , 9.x.2015 [TUA]. Kyushu : Saga Pref., Ogi-cho , 4 females (mounted on one slide) on P. macrophyllus , 28.vii.1983 [ NIAES] . Tanegashima-Is., Nakatane-cho , 2 second instar larvae on young leaves of P. macrophyllus , 30.viii.2011 [TUA]. Ryukyus: Kikai-jima Is., Kikai-cho, 6 second instar larvae on young leaves of P. macrophyllus , 3.ix.2011 [TUA]. Okinawa-hontou Is., Tomigusuku-shi, Noha, 2 second instar larvae on young leaves of P. macrophyllus , 3.ix.2011 [TUA].

Comments. This species has been recognised as Oxythrips since at least the 1980s by non-thrips researchers, because the pronotum bears only one pair of long posteroangular setae. Adults and larvae of this species are found on young leaves of Podocarpus macrophyllus together with Scirtothrips dorsalis . The larva of these two species are uniformly yellow, but can be distinguished easily by differences of sculpture on the body surface, and the structure of the spiracles (see also, Miyazaki & Kudo, 1986; Hoddle & Mound, 2003). In second instar larva, this species is very similar to a grass-living species, Anaphothrips obscurus (Müller) , but the latter species has spiracles with about seven facets having 2–5 internal pores.

Etymology. In reference to the host plants of this species.

Figures

FIGURES 1 – 5. Paroxythrips species. P. agathidis 1 – 3. (1) tergite VII, female; (2) sternites VI – VII, female; (3) sternite VII, male. P. podocarpi 4 – 5. (4) female; (5) male.

FIGURES 6 – 13. Paroxythrips podocarpi n. sp. Female 6 – 11. (6) head & pronotum; (7) antennal segments III – VIII; (8) mesonotum & metascutum; (9) tergite V; (10) tergites VIII – X; (11) sternites VI – VII. Male 12 – 13. (12) tergite IX; (13) sternite V.

FIGURES 14 – 22. Paroxythrips podocarpi n. sp., second instar larva. (14) dorsal aspect; (15) head & pronotum; (16) antenna; (17) meso & metanota; (18) spiracle on mesonotum, left; (19) spiracle on tergite II, right; (20) tergite V; (21) tergites VIII – X; (22) sternite V.