A key to the flat grass scale genus Nipponaclerda (Hemiptera, Coccomorpha, Aclerdidae) Author Schneider, Scott A. text ZooKeys 2019 862 81 87 http://dx.doi.org/10.3897/zookeys.862.35294 journal article http://dx.doi.org/10.3897/zookeys.862.35294 1313-2970-862-81 2C44CFF035214CAC8A4E1642935038A4 Nipponaclerda biwakoensis (Kuwana, 1907) Material examined. UNITED STATES • 11 ♀; Louisiana, Plaquemines Parish, Venice, West Bay South End; 29°7.5'N , 89°17.2'W ; 1 March 2017; R. Diaz leg.; Phragmites australis ; USNM • 2 immatures; same collection data as for preceding; 1 March 2017; R. Diaz leg.; Phragmites australis ; USNM • 2 ♀; Texas, Jefferson County, Port Arthur, near J.D. Murphree WMA; 29°53.2'N , 94°2.2'W ; 11 July 2018; I.A. Knight leg.; Phragmites australis ; USNM • 1 ♀; quarantine interception at California, San Diego, originating from Japan; 2 April 1959; L. Widman leg.; Phragmites sp. or rush; CDFA • 3 ♀; quarantine interception at California, Los Angeles, San Pedro, originating from Japan; 22 March 1960; M.F. Brown, Jr. leg.; Phragmites communis (= australis ); USNM • 1 ♀; quarantine interception at California, Stockton, originating from Japan; 25 May 1961; R.E. DeVol leg.; Phragmites communis (= australis ); USNM • same collection data as for preceding; 3 ♀; 25 May 1961; R.E. DeVol leg.; Phragmites communis (= australis ); CDFA • 2 ♀; quarantine interception at Hawaii, originating from Japan; 25 March 1960; L. Chilson leg.; Phragmites communis (= australis ) stems; USNM. CHINA • 2 ♀; Taiwan, Taichung County; 24°19.2'N , 12°33.5'E ; 22 August 2018; S-G. Syu and J-L. Jhu leg.; Phragmites australis ; USNM • 3 ♀; Hong Kong Special Administrative Region, Tin Shui Wai, Hong Kong Wetland Park, fresh water marsh; 22°28.1'N , 11°0.4'E ; 7 August 2018; B. Brown leg.; Phragmites australis ; USNM. JAPAN • 2 ♀; Fukuoka, Nishi-Ku, Motooka; 33°35.5'N , 13°13.9'E ; 25 October 2018; H. Tanaka leg.; Phragmites australis ; USNM • 3 ♀, syntype; Omi; August 1902; S.I. Kuwana leg.; on rush; USNM • 5 ♀, syntype; Tokio [Tokyo]; 16 April 1906; S.I. Kuwana leg.; Phragmites communis (= australis ); USNM • 4 immatures; same collection data as for preceding • 1 ♀; Tokyo; 18 October 1953; R. Takahashi leg.; Phragmites ; USNM. Notes. Adult females of N. biwakoensis are similar in appearance to N. turanica but the two can be easily distinguished by the traits mentioned above, and in addition by the pattern of sclerotization and by the types of setae located on the anal plate and posterior margin. The posterior end is heavily sclerotized in N. turanica , whereas in N. biwakoensis , moderate sclerotization is more evenly distributed along the marginal rim, becoming more heavily sclerotized in mature females. N. biwakoensis possesses some tuberculate setae on the anal plate and bears only tuberculate or spine-like setae on the posterior body margin. In contrast, only flagellate setae are present on the anal plates of N. turanica and several flagellate setae fall on the posterior body margin. N. biwakoensis was well-illustrated by McConnell (1954) ; additional illustrations were published by Kuwana (1907 ; 1932 ) and Wang (1994) . Several natural enemies of N. biwakoensis are reported in the literature. The parasitoids Astymachus japonicus Howard, Boucekiella depressa Hoffer, Platencyrtus aclerus Xu ( Hymenoptera : Encyrtidae ), and Aprostocetus sp. ( Hymenoptera : Eulophidae ) have been reported from the native range ( Kaneko 2004 ; Xu and Wang 2003 ), which includes China, Japan, and South Korea ( Garcia Morales et al. 2016 ). Knight et al. (2018) reported Neastymachus japonicus Tachikawa, B. depressa , and Astymachus sp. ( Hymenoptera : Encyrtidae ) parasitizing populations in Louisiana, U.S.A. It is difficult at present to determine the origin and timing of invasion to the United States. Specimens of N. biwakoensis were encountered in quarantine interceptions originating from Japan three times in California and once in Hawaii, between 1959 and 1961. But populations have only been collected from the U.S. since 2016 ( Knight et al. 2018 ), suggesting their establishment is a recent event. Infestations have been found in Louisiana and eastern Texas on Phragmites australis , which appears to be the primary host for this species. N. biwakoensis was also reported on species of Agropyron and Juncus ( Wang 1994 ), but these host records should be confirmed through further sampling.