Diognetus vernus, Yasunaga & Schwartz & Chérot, 2023

Yasunaga, Tomohide, Schwartz, Michael D. & Chérot, Frédéric, 2023, Revision of the plant bug genus Diognetus, with descriptions of thirteen new species from the Oriental and Eastern Palearctic Regions (Hemiptera: Heteroptera: Miridae), Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 63 (1), pp. 1-55 : 52-53

publication ID

https://doi.org/ 10.37520/aemnp.2023.001

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scientific name

Diognetus vernus

sp. nov.

Diognetus vernus sp. nov.

( Figs 1E–F View Fig , 5I–M View Fig , 6 View Fig , 21D–G View Fig , 22G–I View Fig , 23 View Fig , 35 View Fig , 36O View Fig ) Yamatolygus flavigenis (misidentification): YASUNAGA (2001): pl. 80, fig. 316 [a female adult figured as flavigenis corresponding to this new species].

Yamatolygus insulanus View in CoL (misidentification): NOZAKI et al. (2016): 81 (faunal list); OH et al. (2018): 482 (faunal list); KIM et al. (2019): 72 (diagnosis).

Yamatolygus sp. 2 : MIYAZAKI et al. (2020): 66, table 1 (life span, Japanese name).

Type material. HOLOTYPE: J, JAPAN: KYUSHU: Nagasaki Pref., Nagasaki City, Kabashima Island , 32.558909, 129.784485, sweeping inflorescence of Castanopsis sieboldii , 12 May 2019, T. Yasunaga ( AMNH) ( AMNH _ PBI 00380756 ) GoogleMaps . PARATYPES: JAPAN: HONSHU: Wakayama Pref., Kushimoto Town, Satokawa, 33.547, 135.654, sweeping flowers of Styrax japonica , 2 Jun 1997, T. Yasunaga, 2 ♀♀; Wakayama Pref., Kozagawa Town, Yasaka, 33.53, 135.81, 13 Sep 1999, H. Matsushita, 1 J ( TYCN); Kozagawa Town, Komorigawa, 33.65, 135.78, 5 Jul 1994, S. Gotoh, 1 ♀ ( TYCN). KYUSHU: Fukuoka Pref., Yame City, Mt. Shakadake, 33.20, 130.84, UV lighting, 23 Jun 2019, T. Nozaki, 1 J ( WCF); Kumamoto Pref., Amakusa City, Ushibuka Town, Mt. Tomi, 32.205105, 130.022851, 23 Jul 2015, T. Nozaki, 1 ♀ ( TYCN); Amakusa City, Uonuki Town, 32.256, 129.999, UV lighting, 12 Sep 2015, T. Nozaki, 1 J ( TYCN); Amakusa City, Futa’ura Town, 32.27, 130.00, UV lighting, 18 Oct 2015, T. Nozaki, 1 ♀ ( WCF); Amakusa City, Tsuruha-yama Park, 32.15, 130.04, UV lighting, 18 Oct 2015, T. Nozaki, 2 JJ 1 ♀ ( WCF) and 8 May 2015, T. Nozaki, 2 ♀♀ ( WCF); Nagasaki Pref., same data as for holotype, 1 ♀ ( TYCN); Nagasaki Pref., same locality (lighthouse), 32.551875, 129.777530, 27 Dec 2019, T. Yasunaga, 1 ♀ ( TYCN); Nagasaki Pref., same locality and date (orange garden), 32.564850, 129.780180, sweeping buds of Eurya japonica, T. Yasunaga , 1 J [5th instar immature form reared then emerging on 29 Dec 2019] ( TYCN); Nagasaki City, Kinkai-Odo, 32.935593, 129.815751, sweeping inflorescence of Castanopsis sieboldii , 8 May 2019, T. Yasunaga, 1 J [reared and dead on Jun 30] ( TYCN); same data, except for date, 4 May 2019, 1 ♀ ( TYCN); Nagasaki City, Kinkai-Tonehara, 32.902671, 129.787376, sweeping inflorescence of Castanopsis sieboldii , 4 May 2019, T. Yasunaga, 1 ♀ [5th instar immature form reared then emerging on May 6 and dead on Jul 2] ( TYCN); Nagasaki City, Tateyama,Mt.Konpira,sweeping flower buds of Eurya japonica , 32.764888, 129.879500, 13 Nov 2021, T. Yasunaga, 2 ♀♀ ( TYCN); Nagasaki City, Aikawa-machi, Agri-Hills Park, 32.809700, 129.797000, sweeping flowers of Ligustrum japonicum , 20 May 2020, T. Yasunaga 1 ♀ [reared then dead on Jul 16] ( TYCN); Nagasaki City, Taira (Azekari, Fishery Port), 32.807615, 129.770780, sweeping flowers and fruits of Eurya emarginata , 15 Dec 2019, T. Yasunaga, 1 ♀ ( TYCN) [5th instar immature form reared then emerging on Dec 17, 2019 and dead on 22 Jun 2020] ( TYCN); same locality and plant, 24 Dec 2019, T. Yasunaga, 1 J [5th instar immature form reared then emerging on 29 Dec 2019 and dead on 26 Apr 2020] ( TYCN); Nagasaki Pref., Goto Islands, Nakadohri Island, Shin-Kamigoto Town, Tsuzuki-Hamano’ura, 32.9608, 129.0277, UV lighting, 5–6 Jun 2022, T.Yasunaga, 2JJ ( TYCN); Tsushima Island, Mizushima Town, Kechi, Tsushima Green Park, 34.2773, 129.3277, flowers of Lithocarpus edulis , 20 May 2020, H. Asanabe, 1 J 1 ♀ ( UMUT); Omura City, Kushima,

32.897077, 129.952977, sweeping fruits of Eurya emarginata , 15 Jan 2020, T. Yasunaga, 1 J [5th instar immature form reared then emerging on 22 Jan 2020 and dead on 23 Apr 2020] ( TYCN). SHIKOKU: Kochi Pref., Tosa-Shimizu City, Cape Ashizuri, 32.73, 133.00, UV lighting, 22 May 1999, M. Takai, 1 J 1 ♀ ( TYCN); Kochi Pref., Cape Muroto, Muroto Skyline Road [Rt 203], 33.25232, 134.17835, sweeping Eurya emarginata , 18 Dec 2019, M. Takai, 2 JJ 3 ♀♀ ( CNC, TYCN); Kochi Pref., Takaoka-gun, Tsuno Town,Tengu-ike, UV lighting, 33.47, 133.00, 21 Jul 2000, M. Takai, 1 ♀ ( TYCN). KOREA: JEJU ISLAND: Jeju City, Eongtto Fall, 33.268440, 126.50000, sweeping Castanopsis inflorescence, 12 May 2008, T. Yasunaga, S.H. Jung & R.K. Duwal ( SNUK).

Description. Body ovoid, slightly elongate in J ( Figs 6A, E View Fig ), relatively small to moderate in size, 4.5–5.2 mm in total length. COLORATION: Body generally castaneous brown (winter-emerging specimens sometimes darkened, cf. Fig. 6C View Fig ). Head somewhat lighter; clypeus usually darkened. Antennae pale brown; segment I sometimes tinged with red; apex of segment II not significantly darkened; segments III and IV dark brown. Labium pale reddish-brown; apical 1/3–1/2 of segment IV infuscate. Pronotum more or less darkened posteriorly, always with yellowish posterior margin (cf. Figs 6A–C View Fig ); calli often with a pair of dark, small spots; pleura broadly chestnut or dark brown; scent efferent system creamy yellow. Hemelytron castaneous, partly mottled with dark maculae; membrane smoky brown, with pale veins and several irregular, semitransparent maculae. Coxae and legs pale brown (creamy brown in fresh specimens); mesofemur with two faint pale rings subapically; apical part of metafemur usually more or less darkened, with two pale apical rings; tarsi brown; apical half of each tarsomere III dark brown. Ventral surface of abdomen castaneous to dark brown, with paler median part. SURFACE AND VESTITURE: As in generic diagnosis; scutellum transversely rugose, sparsely and finely punctate ( Fig. 23 View Fig ); hemelytron with uniformly distributed, fine punctures ( Figs 23 View Fig , 35A View Fig ). STRUCTURE: Antennal segment II as long as or slightly shorter than labium. Labium reaching but not surpassing apex of metacoxa. Scutellum rather flat. Metathoracic scent efferent system as in Fig. 35D View Fig . Metatarsomere II as long as III (Fig. 38E); pretarsal structure as in Fig. 35F View Fig ; parempodia slightly shorter than claw. MALE GENITALIA ( Figs 21D–G View Fig , 35G–K View Fig ): Left paramere with relatively wide protuberance of sensory lobe and rather stout hypophysis that is hooked at apex ( Figs 21D View Fig , 35H–I View Fig ); right paramere with rather small hypophysis ( Figs 21E View Fig , 35H View Fig ). Vesica with MS slightly shorter than LS; LS spatulate apically; RS with distinct TP and developed median hook, lacking field of minute spines ( Figs 21G View Fig , 35J–K View Fig ); apical keel of phallotheca narrow ( Fig. 21F View Fig ). FEMALE GENITALIA ( Figs 22G− I View Fig , 35L− O View Fig ): Sclerotized ring ovoid, rather thin-rimmed ( Figs 22H View Fig , 35L View Fig ); posterior wall with distinctly spinose, rather small dorsal structure ( Figs 35M–N View Fig ); interramal lobe with widened, somewhat angulate lateral margin ( Figs 22G View Fig , 35M View Fig ); more than inner 2/3 of interramal lobe with thick spines ( Fig. 35N View Fig ).

Measurements. See Table 1.

Differential diagnosis. Distinguished from two closely related and sympatric congeners, D. laureus sp. nov. and D. insulanus , by the above key (based mainly on the male genital structures) or by the following key:

1 Basic coloration reddish-brown; labium long, usually exceeding apex of metacoxa, reaching abdominal sternum III or IV; principally associated with Lauraceae View in CoL broadleaf trees. ............................ D. laureus sp. nov.

– Body generally castaneous, not strongly tinged with red; labium reaching but not exceeding apex of metacoxa. ......................................................................... 2

2 Labium about as long as or slightly longer than maximum width (across hemelytra); currently known from Japanese southwestern islands (Koshiki, Tokara, Amami-Oshima and Okinawa Islands), Taiwan and Philippines (Luzon). ........... D. insulanus ( Yasunaga, 1994) View in CoL

– Labium shorter than maximum width; known from warm temperate zone (SW Honshu, Shikoku, Kyushu, Tsushima of Japan and Korean Jeju Island). ............... .................................................... D. vernus sp. nov.

The final instar nymph of D. vernus sp. nov. is very similar in general appearance and dorsal vestiture pattern (cf. Figs 36J, O View Fig ) to that of D. cheimon sp. nov. (cf. Fig. 5 View Fig ); the former can be distinguished from the latter by usually smaller size, tibial dark spots smaller and faint, a pair of clear dark large spots at base (knee) of metatibia ( Fig. 5C View Fig vs. 5K), and smaller dark spot on abdominal scent gland opening ( Fig. 5J View Fig ).

Etymology. Latin adjective vernus (= spring), referring to its frequent occurrence on spring inflorescences.

Biology. MIYAZAKI et al. (2020) reported that a pair of newly emerging adults (in spring) survived for 54 days (J) / 60 days (♀), reared with a fermented milk beverage. Additional tests (Yasunaga, pers. observ.) also confirmed that some adults (winter-emerging population) had longer life span − 187 days (♀, Dec 17, 2019 − Jun 22, 2020); 118 days (J, Dec 29, 2019 − Apr 26, 2020); and 91 days (J, Jan 22, 2020 − Apr 23, 2020). Therefore, two generations may coexist in mid and late spring.

The winter population of D. vernus was predominantly found from the flowers and fruits of Eurya spp. ( Figs 5J− K View Fig ), whereas the spring to early summer population seems to utilize inflorescences of a variety of broadleaf trees, such as Castanopsis sieboldii (Makino) Hatus. , Lithocarpus edulis (Makino) Nakai (Fagaceae) , Ligustrum japonicum Thunb. (Oleaceae) , and Styrax japonica Siebold & Zucc. (Styracaceae) ( YASUNAGA 2001). See also biology section under D. laureus sp. nov. From December to January, any of three Japanese congeners (including immature forms), D. cheimon , D. laureus and D. vernus , may co-occur on inflorescences or fruits of Eurya broadleaf trees.

Distribution. Japan (SW Honshu, Shikoku, Kyushu, Tsushima Island), Korea (Jeju Island).


Tavera, Department of Geology and Geophysics


American Museum of Natural History


Departamento de Biologia de la Universidad del Valle


University Museum, University of Tokyo


Canadian National Collection of Insects, Arachnids, and Nematodes


Departamento de Geologia, Universidad de Chile














Diognetus vernus

Yasunaga, Tomohide, Schwartz, Michael D. & Chérot, Frédéric 2023

Yamatolygus sp. 2


Yamatolygus insulanus

KIM J. & KIM W. & JUNG S. 2019: 72
OH M. & YASUNAGA T. & DUWAL R. K. & LEE S. 2018: 482
NOZAKI T. & NOZAKI Y. & UKI K. & TSUKADA T. 2016: 81
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