Published October 31, 2025 | Version v1
Taxonomic treatment Open

Itoigawacoris venustulus Yasunaga & Mashima, 2025, sp. nov.

  • 1. Research Associate, Division of Invertebrate Zoology, American Museum of Natural History, New York 10024, USA; c / o Nagasaki West High School, SSH Biology Section, Takenokubo 12 - 9, Nagasaki 852 - 8014, Japan
  • 2. Newron Sanitar Co., Settaya-machi 2633 - 3, Nagaoka City, Niigata 940 - 1104, Japan

Description

Itoigawacoris venustulus sp. nov.

Figs. 1–2, 3A–E, 4A–I, 5A–J, 6A–I, 7

Diagnosis. Recognized readily by its unique color pattern and body shape (Fig. 1A–B) and characters provided in above generic diagnosis. At first sight similar in general appearance to Pinalitus nigriceps (Kerzhner, 1988), from which this new species is easily distinguished by the white antennomere III and cuneus. All East Asian Pinalitus members are specialists of Pinaceae conifers (Kerzhner 1988b, Yasunaga 1994, 2001). The nymphs are primarily recognized by the entirely scarlet general coloration (Figs. 1G, 2C–F), and the 4–5th instar immatures have unique microstructures (Fig. 6B–C, E–F).

Description. Head shiny fuscous; buccula narrowly whitish. Antenna dark brown; segment I reddish brown, with more or less darkened apex; segment II almost linear, not thickened towards apex; segment III milky white; segment IV dark grayish brown. Labium shiny chocolate brown, about as long as width across hemelytra; segments II, III and base of IV pale reddish brown. Pronotum fuscous, shining, with pale reddish brown collar; mesoscutum and scutellum shiny fuscous; scutellum with pale apex; propleuron shiny fuscous as in pronotum; other parts of pleurites dark reddish brown; metathoracic scent efferent system pale reddish brown, with darkened anterior margin. Hemelytron brown to dark brown, sometimes partly or widely tinged with red; lateral margin of exocorium (embolium) with a dark, narrow stripe continuing to cuneal margin; cuneus creamy white, narrowly darkened laterally and apically; membrane including veins and areolar cells smoky brown, with a whitish fascia mesally. All coxae whitish brown, partly or widely tinged with orange; all femora orange-scarlet; apices of pro- and mesofemora each with two pale rings; metafemur with two obscure rings; tibia whitish brown; each tarsomere III infuscate. Abdomen shiny orange-brown; ventral surface with a pair of brown fasciae laterally along rows of spiracles; male genital segment (pygophore) dark brown. Male and female genitalia as mentioned in generic description.

Measurements. See Table 1.

Etymology. From Latin, venustus (lovely, beautiful, elegant) with a diminutive suffix (-ulus), referring to its neat general appearance of this new species; the Latin word venustus is also derived from Venus, and the type locality, Mt. ‘Myojo’, means the Venus (planet, also implies Hesperus and Lucifer) in traditional Japanese.

Distribution. Japan (central Honshu, Niigata Prefecture).

Biology. Continuing fieldwork performed by the second author (G. Mashima) in 2024 and 2025 successfully confirmed the life history and breeding host. This mirid is monophagous, associated only with a Japanese boxwood, Buxus microphylla Sieb. & Zucc. (Buxaceae) (Fig. 2B), on which the immature forms and adults were observed to co-occur. The mirid undoubtedly has a univoltine life cycle and overwinters in the egg stage. The early instar nymphs appear on the host leaves in middle May (Fig. 2C–D), when patches of snow remain around the boxwoods (Fig. 2A–B). The newly emerged adults are found from late May to early June, and the annual generation is presumed to be completed until early August.

Under rearing conditions, both mature and late immature forms were observed to suck on an artificial diet (diluted fermented milk beverage, Fig. 2G, cf. Miyazaki et al. 2020) and scavenge on cadavers of other individuals (Fig. 2E). This mirid appears to have in some part of a zoophagous food habit.

Material examined. Holotype (♂), JAPAN: Central Honshu, Niigata Pref., Itoigawa City, Kotaki, Mt. Myojo, N36.936828 E137.817457 (577 m alt.), on Buxus microphylla, 7 Jun 2025, G. Mashima leg. (NWHS) (AMNH_PBI 00380778). Paratypes. JAPAN: Niigata Pref., Itoigawa City, Kotaki, Mt. Myojo, N36.936135, E137.818899 (524 m alt.)—N36.941822, E137.818292 (1184 m alt.), on Buxus microphylla, 7 Jun 2025, G. Mashima, 21 ♂, 17 ♀ (several specimens were reared from 4–5th instar immatures) (AMNH, SNU, TYCN); same data as for holotype, except for date 28 May 2025, 1 ♂, 1 ♀ (final instar nymphs when collected and emerged on 7–8 Jun) (TYCN); same locality, N36.9343, E137.8200 (520 m alt.)—N36.9379, E 137.8162 (610 m alt.), 15 Jul 2024, 1 ♂, 3 ♀ (TYCN); same data except for date 22 Jul 2024, 3 ♂, 8 ♀ (TUAK, TYCN); same data except for date 5 Jul 2024, 3 ♂, 3 ♀ (GMCN). Some additional specimens (damaged during molt to adults) were also collected from Mt. Kurohime (5 km NNW of Mt. Myojo, 36°58’N 137°47’E, Fig. 7) on 29 May 2025 (SNU, preserved in 95% EtOH).

Notes

Published as part of Yasunaga, Tomohide & Mashima, Gō, 2025, A new genus and species of mirine plant bug endemic to central Honshu, Japan, a region receiving the world's heaviest snowfall (Insecta: Hemiptera: Heteroptera: Miridae: Mirinae: Mirini), pp. 397-408 in Zootaxa 5716 (3) on pages 399-406, DOI: 10.11646/zootaxa.5716.3.6, http://zenodo.org/record/17889504

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Linked records

Additional details

Biodiversity

Collection code
AMNH, SNU, TYCN , GMCN , NWHS , SNU , TUAK, TYCN , TYCN
Material sample ID
AMNH_PBI 00380778
Event date
2024-07-05 , 2024-07-15 , 2024-07-22 , 2025-05-28 , 2025-05-29 , 2025-06-07
Verbatim event date
2024-07-05 , 2024-07-15 , 2024-07-22 , 2025-05-28 , 2025-05-29 , 2025-06-07
Scientific name authorship
Yasunaga & Mashima
Kingdom
Animalia
Phylum
Arthropoda
Order
Hemiptera
Family
Miridae
Genus
Itoigawacoris
Species
venustulus
Taxon rank
species
Taxonomic status
sp. nov.
Type status
holotype , paratype
Taxonomic concept label
Itoigawacoris venustulus Yasunaga & Mashima, 2025

References

  • Kerzhner, I. M. (1988 b) Sem. Miridae (Capsidae) - Slepnjaki. In: Ler, P. A. (Ed.), Opredelitel' Nasekomykh Dal'nego Vostoka SSSR, vol. 2 [Keys to the insects of the Soviet Far East]. Nauka, Leningrad, pp. 778-857. [in Russian]
  • Yasunaga, T. (1994) Pinalitus Kelton (Heteroptera, Miridae) and its allied genera of Japan, with descriptions of new genera and species. Japanese Journal of Entomology, 62, 115-131.
  • Yasunaga, T. (2001) Family Miridae Hahn, plant bugs. In: Yasunaga, T., Takai, M. & Kawasawa, T. (Eds.), A Field Guide to Japanese Bugs II. Terrestrial Heteropterans. Zenkoku Noson Kyoiku Kyokai Publ. Co. Ltd., Tokyo, pp. 2 - 96 + 112-351. [in Japanese]
  • Yasunaga, T., Schwartz, M. D. & Cherot, F. (2002) New genera, species, synonymies, and combinations of " Lygus complex " from Japan, with discussion on Peltidolygus Poppius and Warrisia Carvalho (Heteroptera: Mirinae: Mirini). American Museum Novitates, 3378, 1-26. https://doi.org/10.1206/0003-0082(2002)378%3C0001:NGSSAC%3E2.0.CO;2
  • Miyazaki, A., Nishida, M., Uesugi, R., Yamada, U., Yasunaga, T., Serrano Leon, S., Kawashita, S. & Nagashima, T. (2020) Utilizing a synthetic diet containing a fermented milk beverage for rearing terrestrial heteropterans, with new distributional records of four species in Nagasaki Prefecture, Japan. Rostria, 64, 63-69. [in Japanese with English summary]