A redescription of Zavrelia bragremia Guo & WAnG , 2007 ( dipterA : chironomidAe )

Examination of the holotype of Zavrelia bragremia Guo & Wang, 2007, revealed a few mistakes in the original description. Based on the type material and additional adult males from Oriental China, Z. bragremia is here redescribed and figured. An updated identification key to the males of Zavrelia is given.

Here, we redescribe Z. bragremia based on the holotype and additional recently collected specimens, and give an updated identification key to the adult males of Zavrelia.

Material and Methods
Field work was conducted in China to supplement material for Z. bragremia.Studied specimens were slide-mounted in Euparal, following the proce-dures outlined by Saether (1969).Morphological terminology follows Saether (1980).Colouration is based on slide-mounted specimens.Measurements are given as ranges followed by the mean, when four or more specimens are measured, followed by the number of specimens measured (n) in parentheses.Digital photographs were taken with a resolution of 300 dpi using a Leica DFC420 camera mounted on a Leica DM6000 B compound microscope using bright field setting and the software Leica Application Suite 4.8.The holotype is deposited in the College of Life Sciences, Nankai University, Tianjin, China (BDN); several examined specimens are deposited in the NTNU University Museum (NTNU-VM).

Diagnosis
The adult male of Zavrelia bragremia can be distinguished from known species of Zavrelia by the following combination of characters: wing length 0.88-1.04mm; AR 0.91-1.08;frontal tubercle minute; LR 1 about 2.09; laterosternite without seta; anal point with small spinulae between the anal crests at base, but without microtrichia; setiger of superior volsella without conspicuous constriction in apical 1/3.
Colouration.Head capsule and mouthparts light brown, antenna and eyes dark brown to black.Thorax ground colour brown with dark brown stripes anteriorly on scutum, laterally under parapsidal suture, postnotum and on preepisternum, scutellum paler; legs and abdomen brown.

Discussion
Zavrelia bragremia was described based on a single specimen from Sichuan, China by Guo and Wang (2007).By reexamining the holotype, we found that some diagnostic characters in the original description require emendation.For instance, the anal tergite bears three to seven median setae; the anal point does not have two spines (an artifact resulting from slide preparation might have been interpreted as spines, Fig. 7); the anal point has scattered spinules between anal crests at anal point base only.The only complete recently collected specimen of Z. bragremia from Oriental China has also a higher LR 1 value (2.09) -the highest within all known Zavrelia.This was previously unknown since the fore tarsi are missing in the holotype.
Due to slide preparation methods and a distinct variability of Zavrelia species, it is extremely difficult to observe and define key characters to accurately separate species on the basis of their morphology.An intraspecific variability of the type species Zavrelia pentatoma was detected by Giłka (2008).On the other hand, some morphological variable characters of Z. pentatoma have been found as diagnostic in other species like the presence of an obvious constriction in the apical 1/3 of the setiger of the superior volsella (see identification key).Cryptic species, particularly within some of the more widely distributed Zavrelia are thus expected to be revealed.A complete DNA barcode reference library of Zavrelia would be beneficial to explore the species boundaries within this genus, since DNA barcoding (Hebert et al. 2003a, b) has proven effective in biodiversity assessments and taxonomic revisions (e.g.Anderson et al. 2013, Lin et al. 2017).At present (August 2017), however, there is only one species, Zavrelia pentatoma, with DNA barcodes in the Barcode of Life Data Systems (BOLD, http://www.boldsystems.org/).