Niganda phichai Pellinen

Pellinen, Markku J. & Wahlberg, Niklas, 2015, A new species of Niganda Moore, 1879 from Thailand, with descriptions of variation in male genitalia and female facies of N. radialis Moore (Lepidoptera: Notodontidae, Ceirinae), Zootaxa 4033 (1), pp. 94-102 : 95-99

Niganda phichai Pellinen , new species

Figs. 1 and 2

Type material. Holotype (red rectangular label): Thailand, Lampang, Muban Phichai , N 18º18.15’, E 99º31.06’, 240 m, 26.07.2012 (Slide no. MJP 481). Paratypes: Thailand, Lampang, Muban Phichai , 5 ex., 0 3.09.2010 (Slide no. MJP 480), 0 7.10.2011, 18.08.2012, 16.06.2013, and 26.10.2014.

Diagnosis. Niganda phichai is a member of the N. radialis -group. It is easily distinguished from other species in the group by its darker grey color. The dark basal line and white discal spot on the forewing are diagnostic. In males, the presence of specialized paddle-shaped sclerites arising laterally from the vinculum separates the new species from other Niganda species.

Description. Male. Wingspan 33–35 mm (n = 6 individuals). Forewing light brown, darker brown at midcosta, with small white discal spot and black basal line; broken black double antemedial line present, same as double wavy postmedial line; terminal line consisting of black dots. Hindwing light grey. Cteniophore present on fourth abdominal sternite. Eighth sternite sclerotization triangular ( Fig 2 e). Uncus prominent, tapering, with apex bifurcate and deeply concave medially; ornamentation weakly setose; uncal socii sclerotized, long, tapering, apex acute. Gnathos absent. Tegumen large, only weakly fused dorsomedially. Valva rather wide, tapering, costa sclerotised, ventral margin setose, sacculus a large, rounded lobe. Specialized paddle-shaped sclerites arising laterally from vinculum. Transtilla narrow, weakly sclerotised, not fused dorsomedially. Juxta distinctly sclerotised, narrow laterally. Saccus narrow, sclerotised, not extending beyond sclerites of paddle-shaped sclerites. Phallus straight; base of vesica with four cornuti, which are progressively larger inwards ( Figs. 2 b, d). Female. Unknown.

Etymology. The species is named for the village (Muban Phichai ) where the type series was collected. Habitat and Bionomics. Specimens were collected in July, September, and November in a semi-urban landscape with bamboo and fruit trees ( Fig. 3 ) at 350 m elevation in the Lampang district of northern Thailand. N. radialis is quite common in the same landscape.

Table 1. Specimens used for molecular analyses and GenBank accession numbers for gene regions sequences. Dash indicates that the gene region was not successfully amplified.

Code Species Sex Locality Date COI EF1A WINGLESS phichai Phichai Molecular analysis. Analysis of each gene region supports treating N. phichai as a distinct species ( Fig. 4 ). It is genetically distinct from N. donella (5.0% K2P distance in the DNA barcode), N. richaaardi (4.3% K2P distance in the DNA barcode), and N. radialis (4.1% K2P distance in the DNA barcode). There was no variation in the DNA barcode within the new species (0%), suggesting that the barcode can be used reliably for identification. K2P distances among species for the other markers are on a similar order of magnitude ( Fig. 4 ). Unfortunately, we were unable to obtain recently collected specimens of the other species of Niganda , thus we were unable to ascertain the phylogenetic relationships of species in the entire genus. Based on a maximum likelihood analysis of the combined data of the four sampled species ( Fig. 5 ), N. phichai is sister to N. donella and N. richaardi , with N. radialis sister to these three.

Variation in Niganda radialis male genitalia and female facies. In our search for females of N. phichai and to determine the intraspecific genetic variation of its putative closest relative, we sequenced a number of N. radialis individuals of both sexes. Niganda radialis ( Figs. 6 a–c) seems to be a common species at lower elevations (300– 500 m above mean sea level) in northern Thailand, primarily in biotopes with bamboos. Male genitalia are characterized by a rectangular shaped uncus ( Schintlmeister and Pinratana 2007). We noticed that the tip of the uncus in N. radialis is extremely variable from rectangular to almost bilobed, so that the right side of uncus tip (looking dorsally from behind) is almost always somewhat longer ( Fig. 7 ). There is also variation in the vesica with the mid-part bearing large cornuti, the number of which varies from 4 to 7 ( Figs. 8 a–e).

Variation in the male genitalia is apparently restricted to the shape of the apex of the uncus and the number of cornuti in the vesica. Other genitalia structures are more uniform with very little variation. Such variation in male genitalia is often used to justify the description of new species. However, genetic variation in the four sequenced markers is very low within N. radialis (12 sequenced males showing wide variation in male genitalia, plus 4 females), suggesting that the taxon is indeed a single species ( Fig. 4 ). Our material consists of specimens from two different locations approximately 65 km apart.

We were unable to find females of N. phichai despite sampling externally variable individuals. All females turned out to be N. radialis , which showed considerable variation in facies from paler specimens resembling males to darker coloured ones ( Figs. 6 a–b). It is likely that identifying females of the N. radialis -group will require further DNA studies (see Fig. 4 ) and/or dissecting.

Figures

FIGURE 1. Adults of Niganda phichai. A. Paratype, ♂, Thailand, Lampang, Muban Phichai, 0 3.09. 2010, in MJP. B. Holotype, ♂, Thailand, Lampang, Muban Phichai, 26.07. 2012, in MJP. C. Paratype, ♂, Thailand, Lampang, Muban Phichai, 18.08. 2012, in MJP.

FIGURE 2. Male genitalia of Niganda phichai. A – B. Genitalia and phallus, paratype, ♂, Thailand, Lampang, Muban Phichai, 0 3.09. 2010, in MJP (slide no MJP 277). C – D. Genitalia and phallus, holotype, ♂, Thailand, Lampang, Muban Phichai, 26.07. 2012, in MJP (slide no MJP 481). E. Sternite and tergite of 8 th abdominal segment, paratype, ♂, Thailand, Lampang, Muban Phichai, 0 3.09. 2010, in MJP (Slide no MJP 481).

FIGURE 3. Biotope of N. phichai and N. radialis.

FIGURE 4. Neighbour-joining trees of each gene region separately. A. First half of the COI gene (the DNA barcode). B. Second half of the COI gene. C. Elongation factor- 1 alpha gene. D. Wingless gene.

FIGURE 5. Maximum Likelihood topology based on three gene regions. Numbers at nodes are bootstrap values, and branch lengths are proportional to estimated numbers of mutations over time.

FIGURE 6. Naganda radialis. A-B. Female. C. Male.

FIGURE 7. Random sample of N. radialis uncus tips.

FIGURE 8. Male genitalia of N. radialis. A and D. Genitalia and phallus (slide no MJP 485). B and E. Genitalia and phallus (Slide no MJP 486). C and F. Genitalia and phallus slide no MJP 161). G. Abdomen with cteniophores in sternite 4 (arrow) (slide no MJP 376).