Marilia ceylanica Martynov 1936

Pandher, Manpreet Singh, Kaur, Simarjit, Garima, Deepti & Dubey, Anil Kumar, 2021, New records of Caddisflies (Insecta: Trichoptera) from India, Zootaxa 5072 (5), pp. 463-477 : 465

Marilia ceylanica Martynov 1936 , NEW RECORD FOR INDIA

( Figs 6–11 )

Marilia ceylanica Martynov 1936 , 248, textfigs 10, 11, “ Ceylan ” [ Sri Lanka].

Material examined. Andaman and Nicobar Islands Union Territory of India: Great Nicobar Island, Gandhinagar, 6º59’6.54”N, 93º50’46.32”E, 18.xi.2018, Gopi & party ( NZC), 2 males and 1 female .

Diagnosis. Schmid (1958) considered M. ceylanica to be a synonym of M. mixta ( Hagen 1858) , but Malicky (1989) deemed M. ceylanica to be a valid species. The male genitalia of M. ceylanica are similar to those of M. sumatrana Ulmer 1951 . However, in M. ceylanica , segment IX is without any angular horizontal plates above the bases of the preanal appendages ( Malicky 1989; Martynov 1936); but in M. sumatrana segment IX bears angular horizontal plates in that position ( Malicky 1989, 2010). [ Ulmer (1951) described and illustrated tergum X of M. sumatrana without any apical notch in dorsal view, but Malicky (1989) considered that supposed difference from M. ceylanica to be an artifact.] Furthermore, Malicky (1989) compared specimens of M. sumatrana (populations from Sumatra and Thailand) with specimens of M. ceylanica and noted that, in addition to the difference in male genitalia, M. ceylanica can be easily distinguished from M. sumatrana on the basis of additional characters: “the great geographical distance between them, the difference in size ( M. ceylanica is only half the size), and in the male forewing of the Thai species [ M. sumatrana ] the veins R4, R5 and M1+2 (sensu Ulmer) arise practically from one point, in M. ceylanica the last two form a fork” [translated from German]. Malicky (2013) more recently expressed his frustration for diagnosis of most species in Marilia as follows: “So we have to realize that our current methods of species identification in the genus Marilia are insufficient and that any attempt at identification is a pure game of chance” [translated from German]. Future revisionary work combining morphological and molecular studies could provide better insight to the species of this genus.

Distribution. India (Andaman & Nicobar Islands UTI, Great Nicobar Island), Sri Lanka, Indonesia (Sumatra, Java, Laos), Thailand, Vietnam.

Figures

FIGURES 6–11. Marilia ceylanica Martynov 1936, male genitalia. 6, left lateral; 7, dorsal; 8, dorsal enlarged; 9, right inferior appendage, ventral; 10, phallus, left lateral; 11, phallus, ventral.