Macroplea Samouelle, 1819

Lou, Qiaozhe, Yu, Peiyu & Liang, Hongbin, 2011, Two new species of Macroplea Samouelle (Coleoptera: Chrysomelidae: Donaciinae) from China, with a key to all known species, Zootaxa 3003, pp. 1-21 : 2

Genus Macroplea Samouelle, 1819

Macroplea Samouelle, 1819: 211 (Type species Donacia zosterae Fabricius, 1801 ). Apelma Billberg, 1820: 57 (Type species Donacia zosterae Fabricius, 1801 ).

Haemonia Dejean, 1821: 114 (Type species Donacia zosterae Fabricius, 1801 ).

Diagnosis. Dorsum and legs yellow or brown ( Figs 1, 3, 24, 26, 50–53); vertex with dense pubescence ( Figs 6, 29, 50–53); antenna long, extending beyond middle of elytron ( Figs 1–4, 50, 52, 53), or short, not extending beyond middle of elytron ( Figs 24–27); pronotum with setae at anterior angles ( Figs 5, 28, 56–59); pronotum with distinct anterior and posterior beads ( Figs 5, 28, 56–59); punctures along elytral striae arranged more or less in paired rows ( Figs 1, 3, 50–53), or in single rows ( Figs 24, 26); elytron with or without spine at outer apical angle ( Figs 12, 35, 64–67); metafemur slender, without tooth ( Figs 1–4, 24– 27, 50–53); profemur with a short linearly arranged brush of setae basally on posterior surface ( Figs 16, 36); metatarsus with markedly reduced pubescence, fifth tarsomere elongate, at least as long as basal three combined ( Figs 10, 39, 68, 70, 71); endophallus with two ELDs fused, enclosing MEG, without pELD ( Figs 21, 22, 47–49, 74, 75, 77, 78, 81–83).

Distribution. Europe, northern Africa ( Algeria), Middle Asia, Siberia, Far East, China and Japan. Distribution in China: Heilongjiang, Hebei, Tianjin, Ningxia, Gansu, Xinjiang, Jiangsu, Hubei, Sichuan, Guizhou ( Fig. 85).

Host plants. Ranunculus L. ( Ranunculaceae ), Carex L. ( Cyperaceae ), Brasenia Schreb. ( Cabombaceae ), Potamogeton L. ( Potamogetonaceae ), Myriophyllum L. ( Haloragaceae ), Ruppia L. ( Zosteraceae ), Zostera L. ( Zosteraceae ), Sparganium L. ( Sparganiaceae ) ( Bieńkowski & Orlova-Bieńkowskaja, 2004), Vallisneria L. ( Hydrocharitaceae ), Ottelia Pers. ( Hydrocharitaceae ) and Hippuris L. ( Hippuridaceae ) (recorded in this paper).

Biology. Macroplea is a fully aquatic genus. They live in lentic or lotic water. Both M. appendiculata and M. mutica live in brackish as well as fresh water ( Borowiec, 1984; Kölsch et al., 2006; Saari, 2007; Mende et al., 2010). According to Mende et al. (2010: 101), immobility (cannot swim or fly) is believed to be a specific feature of M. mutica . However, three specimens of M. japana examined in this study were collected by light trap.

Remarks. Identification of species of Macroplea is difficult, despite the genus being less speciose. Many workers have used external morphology, male genitalia, ecological features, and molecular data to delimit species of this genus ( Freude et al., 1966; Daccordi & Ruffo, 1978; Mohr, 1985; Beenen & Winkelman, 1989; Hayashi & Shiyake, 2001; Kölsch et al., 2006). We have followed many of these workers to enhance the reliability of the key. Species of Macroplea can be separated from those of Neohaemonia Székessy in new world by the following characters: 1) vertex with dense pubescence (with a glabrous patch in Neohaemonia ); 2) pronotum with setae at anterior angles (such setae absent in Neohaemonia ); 3) pronotum with distinct anterior and posterior beads (such beads absent in Neohaemonia ); 4) profemur with a short linearly arranged brush of setae basally on posterior surface (such brush of setae absent in Neohaemonia ); 5) endophallus without pELD (pELD present in Neohaemonia ).