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Dive into the research topics where Tadashi Ishikawa is active.

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Featured researches published by Tadashi Ishikawa.


Zootaxa | 2015

The assassin bug subfamily Tribelocephalinae (Hemiptera: Heteroptera: Reduviidae) from Japan, with descriptions of eight new species in the genera Opistoplatys and Abelocephala

Tadashi Ishikawa; Wanzhi Cai; Masaaki Tomokuni

We examined the Japanese species of the reduviid subfamily Tribelocephalinae. We identified two species of Opistoplatys Westwood, which is the genus with the second largest number of species, and six species of Abelocephala Maldonado, which to date has been referred to as a monotypic genus. All the identified species represent new species and they are described herein under the following names: Opistoplatys minimus sp. nov., Opistoplatys flavolineatus sp. nov., Abelocephala albula sp. nov., Abelocephala araiorum sp. nov., Abelocephala nakatai sp. nov., Abelocephala yaeyamensis sp. nov., Abelocephala major sp. nov., and Abelocephala longiceps sp. nov. Species of Abelocephala can be distinguished from each other based on multiple morphological characters such as body length, ratio of the length to the width of the head, color of the posterior pronotal lobe, shading and pattern of color in the hemelytral basal part, and acuteness or roundness in the apical angle of the outer (larger) cell on the hemelytral membranes. We confirmed that the Japanese tribelocephalines are ground inhabitants living under and within the forest leaf litter. Our results inferred that species of Opistoplatys have positive phototaxis but generally move by walking, whereas species of Abelocephala have negative phototaxis but frequently fly above the forest floor.


Journal of Insect Science | 2016

Intraspecific Variation of Eysarcoris guttigerus (Hemiptera: Pentatomidae) in Japanese Southwest Population Based on Mitochondrial DNA

Takuya Yamaji; Tadashi Ishikawa; Masashi Nomura

The white-spotted globular bug Eysarcoris guttigerus (Thunberg) (Hemiptera: Pentatomidae) is widely distributed in East Asia and the Pacific region. In Japan, the species is found in grassy or composite weeds in the western area of the main islands and Ryukyu Islands of Japan. One notable characteristic of the Eysarcoris genus is the two white spots on the scutellum. This is not the case with the Ishigaki Island population, however, which sports red spots instead of white, suggesting that intraspecific variation exists in the species. Therefore, we investigated intraspecific variation in E. guttigerus using mitochondrial NADH dehydrogenase subunit 2 (ND2), cytochrome oxidase subunit 1 (CO1), cytochrome b (Cytb), tRNA-Serine (tRNAser), NADH dehydrogenase subunit 1 (ND1), and 16S ribosomal RNA (16SrRNA) genes from 13 populations of Japan. The obtained maximum likelihood phylogenetic tree was divided into three groups—Group 1: Mainland, Group 2: Central Ryukyu Islands (Okinawa-Amamioshima Islands), and Group 3: South Ryukyu Islands (Ishigaki Island). The Ishigaki population was significantly separated from the other populations with consistent differences in spot color. The estimated period of divergence between the Ishigaki population and the other populations was consistent with the period of formation of the Kerama Gap in the Ryukyu arc. Thus, the process of formation of the Kerama Gap may have influenced the intraspecific variation of E. guttigerus.


Zootaxa | 2016

Resolving the taxonomy and nomenclature of Metochus abbreviatus (Hemiptera: Heteroptera: Rhyparochromidae)

Előd Kondorosy; Tadashi Ishikawa; Dávid Rédei

The identity of Metochus abbreviatus Scott, 1874 (Hemiptera: Heteroptera: Rhyparochromidae: Rhyparochrominae: Rhyparochromini) is clarified based on reexamination of the lectotype. The subjective synonymy of Dieuches kreyenbergi Breddin, 1906 with M. abbreviatus is confirmed. The following new subjective synonymies are proposed: Rhyparochromus erosus Walker, 1872 = Metochus abbreviatus Scott, 1874, syn. nov. = Metochus holsti Distant, 1918, syn. nov. Bibliographies of the names are provided and it is demonstrated that the name M. abbreviatus is in prevailing usage. Reversion to the senior name Rh. erosus is considered to be undesirable, therefore an application has simultaneously been submitted to the International Commission on Zoological Nomenclature to give the specific name abbreviatus precedence over the specific name erosus. The diagnostic characters, bionomics and distribution of the species are briefly reviewed.


Insect Systematics & Evolution | 2016

Twelve new species of the Asian plant bug genus Ernestinus Distant (Heteroptera: Miridae: Bryocorinae: Eccritotarsini), with emphasis on unique biology and descriptions of three additional new eccritotarsine species

Tomohide Yasunaga; Tadashi Ishikawa

The Asian eccritotarsine plant bug genus Ernestinus Distant is diagnosed, redescribed and discussed, on the basis of reevaluation on the effective taxonomic characters including the genitalic structures of both sexes as well as the unique biology. Nineteen congeners are now known, including a dozen of new species herein described from Indonesia (from the Sundaland to the Wallacea), SW Japan, Laos, Nepal, Taiwan, Thailand and Vietnam. All the new species were observed to inhabit leaves (mostly abaxial surfaces) of the Araceae monocots (particularly of the subfamily Aroideae), on which the adults and every instar immature forms are frequently gregarious together. In addition, three new species in three eccritotarsine genera, Diocleroides Stonedahl & Hernandez, Dioclerus Distant and Harpedona Distant, confirmed during examinations of related materials from Nepal and Thailand, are described. Annotated checklist of all the congeners and a key to all currently known species are provided, to facilitate species identifications.


Entomological Science | 2010

Pteromalid parasitoids (Hymenoptera) of Oulema oryzae (Kuwayama) (Coleoptera: Chrysomelidae) from Japan, with notes on Pteromalus bifoveolatus

Tsuyoshi Ishizaki; Tadashi Ishikawa

The present paper discusses three Japanese species of Pteromalidae reared from cocoons of the rice beetle Oulema oryzae (Kuwayama, 1929) (Coleoptera, Chrysomelidae). Pteromalus cyclostomus Ishizaki sp. nov. is described. Spaniopus monospilus (Thomson, 1878) and Usubaia liparae Kamijo, 1983 are newly recognized as parasitoid wasps of O. oryzae, and the former is also recorded from Japan for the first time. Pteromalus bifoveolatus Förster, 1861 is also newly recorded from Japan, with a new host record from Samia cynthia pryeri (Lepidoptera: Saturniidae).


The Bulletin of zoological nomenclature | 2017

Case 3724 — Metochus abbreviatus Scott, 1874 (Insecta, Heteroptera): proposed precedence over Rhyparochromus erosus Walker, 1872 (currently Metochus erosus)

Dávid Rédei; Előd Kondorosy; Tadashi Ishikawa; Berend Aukema; Harry Brailovsky; Attilio Carapezza; Jürgen Deckert; Pablo M. Dellapé; Cuiqing Gao; Thomas J. Henry; Sunghoon Jung; Petr Kment; M. B. Malipatil; Jane O'Donnell; G. G. E. Scudder; Masaaki Tomokuni; Jing-Fu Tsai

Abstract. The purpose of this application, under Article 23.9.3 of the Code, is to conserve the widely used specific name Metochus abbreviatus Scott, 1874, for a species of rhyparochromid bugs from East Asia. The name is threatened by the senior subjective synonym Rhyparochromus erosus Walker, 1872, which has seldom been used since its first publication. Therefore, precedence of the name Metochus abbreviatus Scott, 1874 over Rhyparochromus erosus Walker, 1872 is proposed.


Zootaxa | 2016

The assassin bug genera Nagustoides and Stenolemus (Hemiptera: Heteroptera: Reduviidae) newly recorded from Japan

Tadashi Ishikawa; Takeru Naka

Two assassin bug genera, Nagustoides Miller, 1954 of Harpactorinae and Stenolemus Signoret, 1858 of Emesinae (Hemiptera: Heteroptera: Reduviidae), are recorded from Japan for the first time, with the presence of the representative species N. lii Zhao, Cai & Ren, 2006 and S. alikakay Rédei & Tsai, 2010. Distribution ranges of the two species are revised by the present finding.


Zootaxa | 2016

First record of the thread-legged assassin bug genus Proguithera from Japan, with description of a new species (Hemiptera: Heteroptera: Reduviidae).

Tadashi Ishikawa; Takeru Naka

The thread-legged assassin bug genus Proguithera Wygodzinsky, 1966 of the emesine tribe Leistarchini (Hemiptera: Heteroptera: Reduviidae) is recorded from Japan for the first time, and a new species P. kiinugama sp. nov., the third representative of this genus, is described based on specimens from Ishigaki-jima Island in the Ryukyu Islands. This new species can be distinguished from its congeners primarily by the absence of a median longitudinal sulcus on the anterior pronotal lobe, forewing with an incomplete cross vein connecting the M+Cu vein and a submarginal vein basad of the discal cell, and the anteroventral series of the profemur consisting of about 30 spine-like setae.


Zootaxa | 2015

The assassin bug subfamily Harpactorinae (Hemiptera: Reduviidae) from Vietnam: an annotated checklist of species

Truong Xuan Lam; Wanzhi Cai; Masaaki Tomokuni; Tadashi Ishikawa

A checklist of all known Vietnamese species of the assassin bug subfamily Harpactorinae (Hemiptera: Heteroptera: Reduviidae) is presented with distributional and taxonomic notes. Sixty-five species in 35 genera of the subfamily are recognized in Vietnam. Eleven genera and 32 species are reported herein for the first time from this country. Newly recorded genera are Henricohahnia Breddin, 1900, Kalonotocoris Miller, 1941, Lingnania China, 1940, Lopodytes Stål, 1853, Macracanthopsis Reuter, 1881, Sclomina Stål, 1861, Serendiba Distant, 1906, Serendus Hsiao, 1979, Vesbius Stål, 1866, Villanovanus Distant, 1904, and Yolinus Amyot & Serville, 1843. New record species are Biasticus confusus Hsiao, 1979, B. flavinotus (Matsumura, 1913), Cosmolestes annulipes Distant, 1879, C. pulcher Hsiao, 1979, Cydnocoris fasciatus Reuter, 1881, C. gilvus (Burmeister, 1838), Endochus nigricornis Stål, 1859, Henricohahnia vittata Miller, 1954, Isyndus heros (Fabricius, 1803), I. pilosipes Reuter, 1881, Kalonotocoris curvipes Miller, 1941, Lingnania braconiformis China, 1940, Lopodytes spectabilis Miller, 1941, Macracanthopsis nodipes Reuter, 1881, Sclomina erinacea Stål, 1861, Serendiba nigrospina Hsiao, 1979, S. staliana (Horváth, 1879), Serendus geniculatus Hsiao, 1979, Sphedanolestes annulipes Distant, 1903, S. gularis Hsiao, 1979, S. impressicollis (Stål, 1861), S. pubinotus Reuter, 1881, S. trichrous Stål, 1874, S. xiongi Cai & Cai, 2004, Sycanus croceus Hsiao, 1979, Velinus annulatus Distant, 1879, V. malayus (Stål, 1863), V. rufiventris Hsiao, 1979, Vesbius purpureus (Thunberg, 1784), V. sanguinosus Stål, 1874, Villanovanus nigrorufus Hsiao, 1979, and Yolinus albopustulatus China, 1940. All the species are examined with Vietnamese materials except for Agriosphodrus dohrni (Signoret, 1862), Cydnocoris russatus Stål, 1867, and Sycanus atrocoeruleus Signoret, 1862.


Journal of Pest Science | 2012

Seasonal abundance of Maiestas banda (Hemiptera: Cicadellidae), a vector of phytoplasma, and other leafhoppers and planthoppers (Hemiptera: Delphacidae) associated with Napier grass ( Pennisetum purpureum ) in Kenya

Shinsaku Koji; Satoshi Fujinuma; Charles A. O. Midega; Hassan M. Mohamed; Tadashi Ishikawa; Michael R. Wilson; Manfred Asche; Simon Degelo; Tarô Adati; John A. Pickett; Zeyaur R. Khan

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Shûji Okajima

Tokyo University of Agriculture

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Wanzhi Cai

China Agricultural University

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Dávid Rédei

Hungarian Natural History Museum

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Satoshi Fujinuma

Tokyo University of Agriculture

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