A review of Thysanarthria with description of seven new species and comments on its relationship to Chaetarthria (Hydrophilidae: Chaetarthriini)
Fikáček Martin, Liu Hsing-Che
Acta Entomologica Musei Nationalis Pragae 59(1): 229-252, 2019
Published online: 20th June 2019
Published in print: 10th August 2019
Abstract: The Old World genus Thysanarthria Orchymont, 1926 is reviewed taxonomically and
compared to the related genus Chaetarthria Stephens, 1835. Chaetarthria is
considered to consist of three groups differing in the morphology of male
genitalia and surrounding sclerites: (1) large Old World Chaetarthria which
seems to stand apart of the remaining groups, and (2) European Chaetarthria
plus (3) American Chaetarthria which both share the male sternite 8 with a long
median projection with Thysanarthria. The reduced mesal part of male sternite 9
is shared by European Chaetarthria and Thysanarthria, supporting their close
relationship proposed by previous molecular analyses. Sixteen species are
recognized within Thysanarthria which differ in the details of the morphology of
the aedeagus illustrated for all species. Seven species are described as new: T.
bifida sp. nov. (Thailand), T. cardamona sp. nov. (India: Kerala), T. chui sp.
nov. (Taiwan), T. persica sp. nov. (southern Iran), T. saurahana sp. nov.
(Nepal), T. trifida (Laos), and T. wadicola sp. nov. (Oman). New records are
provided for T. ceylonensis Hebauer, 2001 (new to India: Madhya Pradesh), T.
championi (Knisch, 1924) (new to Afghanistan, India: Arunachal Pradesh, China:
Yunnan, and Myanmar), T. madurensis Hebauer, 2001 (new to Nepal and India:
Kerala), and T. siamensis Hebauer, 2001 (new to India: Uttarkhand, Nepal and
Laos). Chaetarthriomorphus sulcatus Chiesa, 1967 is revealed as a junior
synonym of Chaetarthria championi Knisch, 1924, and lectotypes are designated
for both these taxa. An undescribed species of the American group of
Chaetarthria is recorded from Saudi Arabia either as an accidental introduction
or due to mislabeling; the species is illustrated but not described.
Key words: Hydrophilidae, Chaetarthriinae, Thysanarthria, Chaetarthria, systematics, distribution, new species, new records, lectotype designation, genitalia morphology, introduced species