Marilia megalopos , Morse, John C., 2017

Morse, John C., 2017, Lannapsyche and Marilia species of China (Trichoptera: Odontoceridae), Zootaxa 4320 (1), pp. 81-99: 95-97

publication ID

publication LSID

persistent identifier

treatment provided by


scientific name

Marilia megalopos

n. sp.

Marilia megalopos  , n. sp.

( Fig. 11View FIGURE 11)

Diagnosis: The new species is very similar to Marilia discaulis  from southeastern China in the venation of forewings and the shape of male genitalia, but the new species can be separated from the latter in having (1) large compound eyes appressed against each other along the median axis of the vertex, (2) with only a single vertexal mediantennal wart visible; (3) fork 2 of each forewing is petiolate and (4) R2 of each hind wing is very short, running into R1 near the middle of the discoidal cell; (5) the basal segment of each inferior appendage has a distinctive basomesal setose bump. In contrast, in M. discaulis  the compound eyes are separated on the midline, fork 2 of each forewing is sessile, R2 of each hind wing is very long, running into R1 at the level of the end of Sc, and the basal segment of each inferior appendage is without a distinctive basomesal setose bump. The new species is also similar to Marilia enikiana  from Laos in the venation of fore- and hind wings, but the new species differs from it in having segment IX on each side (1) with 2 longitudinal grooves and (2) with the broadest median portion at least 2 times as long as the ventral margin in lateral view, and (3) the apex of segment X is excised into 2 lobes in dorsal view. In contrast, in M. enikiana  segment IX on each side has only one longitudinal groove, the median portion of segment IX is at most 1.5 times as long as the ventral margin in lateral view, and the apex of segment X is not divided.

Male (in alcohol). Body small, head almost completely occupied by large, dark brown compound eyes appressed against each other along middle 1/3 of median axis, only single vertexal medi-antennal wart visible in dorsal view; thorax brown, maxillary palps light brown; thoracic setal warts concolorous with head and thorax; thoracic legs yellowish brown, foreleg tibiae and tarsi slightly darker than those on mid- and hind legs. Forewing membranes light brown, subapical margins convex.

Forewings ( Fig. 11View FIGURE 11 Fa). Each with length 6.5–7.0 mm (n = 4); R1 confluent with R2 almost at same level as end of Sc; forks I, II, and V present, forks I and V sessil, fork II stalked; MA fused with stalk of fork II and with base of R5 for about half its length. Hind wings similar to those of Marilia enikiana  : free base of R2 (arrow) very short, running into R1 far basal of anastomosis, about mid distance of discoidal cell, Cu1 stem aligned with fused Cu1+MP, with MP forming an acute angle (about 40°) at the confluence of MP and Cu1 ( Fig. 11View FIGURE 11 Fp, arrow). Long basal brush present on small anal lobe at base of each hind wing, this brush composed of about dozen, very fine setae, with same color and thickness as marginal hairs ( Fig. 11View FIGURE 11 Fp).

Male genitalia. Tergum IX with clear posterior margin, 3.5 times as broad as its median length in dorsal view ( Fig.11BView FIGURE 11); in lateral view, height of segment IX nearly 4 times length of dorsal margin and more than 4 times longer than ventral margin, broadest mid laterally, dorsolateral and mid lateral longitudinal grooves dividing each side of segment IX into 3 parts ( Fig. 11AView FIGURE 11); anterior margin protruded in approximate 140° angle at 1/3 distance from ventral margin, lateroapical corners of segment IX not developed, mid lateral apical lobe forming approximately 100° angle extending well past dorsal and ventral posterior ends of tsegment IX in lateral view ( Fig. 11AView FIGURE 11). Segment X forming long hood, about 2.5 times as long as tall, with ventral margins convex in lateral view; in dorsal view, basal half of segment X broad, distal half compressed, with apex divided for short distance ( Fig. 11BView FIGURE 11). Preanal appendages compressed, elongate, foliaceous, about 2 times as long as tergum IX ( Fig. 11AView FIGURE 11). Inferior appendages much longer than segment X and preanal appendages, directed caudodorsad nearly to apex of tergum X; each with coxopodite dark and stout, almost parallel-sided, with distinctive baso-mesal setose bump ( Figs. 11A, 11C, bView FIGURE 11.bum.); in ventral view, apical segment small, narrow at base and tip, typically water-drop shaped. Phallobase constricted almost at middle, tube-like in basal 1/2, with distal half slightly enlarged and directed backward; phallicata retracted within phallobase in our specimens ( Fig. 11DView FIGURE 11), phallotremal sclerite lightly sclerotized, U-shaped in ventral view.

Holotype male. PR CHINA: Gui-zhou Province , Li-po County, Da-qi-kong, N25.7°, E107.5°, alt. 1000 m, 6 July 1994, Coll. Du Y-z.GoogleMaps 

Paratypes. Same data as holotype, 4 males (NAU); 2 males (CUAC).

Etymology: Greek, megalopos  = large-eyed, referring to the large compound eyes meeting each other at the median axis.

Distribution: Oriental Biogeographic Region, southwestern China (Gui-zhou).