Amnihayesomyia Niitsuma, 2007

Hongqu, Tang & Niitsuma, Hiromi, 2020, Review of the genus Amnihayesomyia Niitsuma (Diptera: Chironomidae: Tanypodinae), with descriptions of three new species from China, Zootaxa 4743 (3), pp. 411-418 : 412-413

Genus Amnihayesomyia Niitsuma

Amnihayesomyia Niitsuma, 2007: 110 ; Cranston & Epler 2013: 79. Type species: Amnihayesomyia ikawensis Niitsuma by original designation.

Emended diagnosis. Male hypopygium. Tergite IX with rows of posterior setae. Gonocoxite lobe bifid, with setae arising from distinct conical tubercles. Phallapodeme long, anteriorly broad and curved dorsally. Gonostylus robust and right-angled.

Remarks. The generic diagnosis for the adult was given by Niitsuma (2007). It was not amended when the Conchapelopia nepalicola group consisting of four species from Nepal was transferred to this genus by Cranston & Epler (2013), although the Nepalese males have peculiar features for the genus. Therefore, the generic diagnosis for the male adult should be emended to safely accommodate the species group with the Chinese species described here.

The scutal tubercle is minute in the following five known species: A. dartofi (Murray) , A. nepalicola (Murray) , A. setipalpis (Murray) and A. buidonnai (Murray) from Nepal, and A. ikawensis Niitsuma from Japan ( Murray 1976 for the former four species, Niitsuma 2007 for the last species), but absent in three Chinese species described here: A. vittata sp. n., A. subflava sp. n. and A. tibetica sp. n. The number of preepisternal setae is 2–12 in these Chinese species and 0–1 in the Japanese species, while these Nepalese species lack the seta on the preepisternum. Considering the wing pattern, Japanese A. ikawensis and Chinese A. vittata sp. n. possess banded wings, whereas the resting six species have plain wings. The robust apical setae of the second palpomere also show great variation in number and shape among species. Three species of A. dartofi , A. ikawensis and A. tibeica sp. n. have no robust apical seta on the palpomere. In A. subflava sp. n., the robust setae are slightly shorter and thicker than the normal setae. In A. vittata sp. n., one of the robust setae may be deformed into the stout spine, which is shorter than the robust setae in the male, but almost as long as those in the female.

Among the members of Thienemannimyia group sensu Silva & Ekrem (2016), the male hypopygium of Amnihayesomyia is indeed most similar to those of Thienemannimyia and Lobomyia in having the cylindrical gonocoxite with a bifid lobe but differs from them in the lobe with setae arising from distinct conical tubercles, which is unique in this genera group.

The pupa shares the following features with those of Conchapelopia , Helopelopia , Coffmania and Metapelopia : thoracic horn with a plastron plate and a distinct corona, and thoracic comb absent or poorly developed. However, it is distinct in the abdominal segment VIII with three LS-setae ( Niitsuma 2007). In the latter four genera, even in the other members of Thienemannimyia group, the pupal abdomen possesses five LS-setae on the segment VIII ( Fittkau & Murray 1986 for Conchapelopia and Helopelopia ; Hazra & Chaudhuri 2000, Niitsuma 2008 for Coffmania ; Silva et al. 2014 for Metapelopia ).

Within the Thienemannimyia group, the combination of a 2-segmented b-sensillum of maxilla and ligula teeth ending in a concave row occurs in the larvae of Telopelopia , Arctopelopia , Thienemannimyia , Rheopelopia , Meropelopia , Yarrhpelopia and Metapelopia , as well as Amnihayesomyia . However, the larva of Amnihayesomyia is separable from the others in the relatively narrow pseudoradula with 6–8 rows of granules ( Niitsuma 2007). The pseudoradula is composed of 10–12 rows of granules in Arctopelopia , Thienemannimyia , Rheopelopia and Mero- pelopia ( Cranston & Epler 2013), and uniform and broad granulation in Telopelopia , Metapelopia and Yarrhpelopia ( Cranston & Epler 2013 for Telopelopia, Silva et al. 2014 for Metapelopia, Cranston 2017 for Yarrhpelopia ). Among the known genera of Thienemannimyia group, the simple cephalic seta S 10 of this genus is unique in the position, posterolateral to the multibranched S 9 and anterolateral to the VP, although Niitsuma (2007, fig. 38) made a mistake in numbering of the cephalic setae.

The known pupa and larva of this genus are still those of A. ikawensis only. There is no required amendment to the diagnoses by Niitsuma (2007) for these life stages.