Montiphylax, Ruiter, David E. & Mutch, Robert A., 2019

Ruiter, David E. & Mutch, Robert A., 2019, Montiphylax, (Trichoptera, Limnephilidae), a new genus to accommodate the western North American species: Stenophylaxantennatus Banks, 1900, Philocascathor Nimmo, 1971, and Philocascaalba Nimmo, 1977, ZooKeys 845, pp. 153-180 : 155-156

Montiphylax gen. n. Figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

New combinations.

Stenophylax antennatus Banks, 1900, new combination (type species); Philocasca antennata (Banks, 1900), new combination; Philocasca alba Nimmo, 1977, new combination; Philocasca thor Nimmo, 1971, new combination

Description.

Adult (Fig. 1). Head to wingtip length: Montiphylax antennatus male - 19-21 mm (n = 5); antennatus female - 19-21 mm (n = 5). Montiphylax albus male - 18-19 mm (n = 8); albus female - 18-20 mm (n = 3). Montiphylax thor male - 18-21mm (n = 3). Eyes large with numerous fine setae located between ommatidia. Head rectangular in dorsal view; ocelli large, posterior ocelli set midlength. Several small setae scattered on head surface, primarily between and behind posterior ocelli. Two pair of warts evenly spread between anterior and posterior ocelli. Posterior warts small, linear with acute apices. Malar projection as long as length of 1st labial palp segment. Antennae shorter than wing length, stout, basal segment shorter than eye width.

Pronotal warts oval, wide, nearly touching mesally. Mesonotal macrosetae in linear row, basal warts located midlength, slightly merged but not fused into a single smooth oval wart; mesocutellar macro setae scattered linearly, less fused than mesonotal wart; most dorsal head and thoracic setae pale.

Forewings (in alcohol) reddish brown, finely irrorate; third radial vein and discoidal cell with a fairly long common boundary approximately equal to length of the first transverse vein; discoidal cell longer than its pedicel; all apical cells without pedicels. Anterior and posterior anastomosis nearly perpendicular to wing length, clearly located distad from posterior anastomosis. Hindwings brown, without irrorations; discoidal cell longer than its pedicel; all apical cells without pedicels. Anterior anastomosis perpendicular to wing length, clearly located distad from posterior anastomosis. Posterior anastomosis strongly oblique to wing margin. Most setae on wing membrane recumbent.

Legs long and thin, tarsi long with basal segment more than 0.5 length of mesotibia, Apical tarsal segments without ventral spines. Spines on legs black, spurs golden, spur count 1-2-4.

Male genitalia (Figs 6, 8, 9). Eighth segment without adornment, slightly swollen on dorsal apical margin. In lateral view 9th segment annular, narrowed dorsally and broadest at base of short, tall inferior appendages; deeply invaginated dorsally in caudal view. Tenth segment cupped anteriorly, appearing as two, slightly fused hemispheres extending broadly anteriad within the 9th. Superior appendages of 10th fused to intermediate appendages; in lateral view, variously broad and projecting, diagnostic by species. In dorsal view intermediate appendages of 10th extended mesally as two long, tapered, downward directed, thin parallel projections. Inferior appendages of 10th short, broad ventrally; nearly fused mesally. Phallus with heavily sclerotized, dorsomesal, conical projection at base of dorsolateral parameres. Parameres heavily sclerotized, projecting fingerlike, parallel to body of phallus; shape diagnostic by species. Apical portion of phallus membranous, extensile, with ejaculatory duct ending in an apical, upward directed, sclerotized cup.

Female genitalia (Figs 7, 10), female of M. thor unknown. Ninth tergite and sternite fused laterally; 10th segment fused to 9th, broadly projecting distad to blunt, rounded apex in lateral view. In dorsal view 10th apex cleft to approximately midlength mesally. In ventral view, 9th sternal lateral projections fused to mesal supragenital plate. Vulvar scale stout, broadly merged to 8th segment laterally, with wide, smoothly conical, medial lobe slightly shorter than lateral lobes.

Larva (Figs 2-4), (n = 3 antennatus and 4 albus ; larva of M. thor unknown). Head nearly circular in dorsal view, widest mid-length, rugulose, specimens in alcohol rust colored. Muscle scars indistinct. Typical limnephiloid setation, without accessory setae. Anterior ventral apotome small, equal, or shorter than ventral ecdysial suture. Submental sclerites distinctly separated from stipes and mesally separated.

Prothorax rust colored (in alcohol) like head; setae scattered, without distinct setal areas; in lateral view, slight transverse indentation approximately midlength; posterior margin thick and dark, with deep, preceding furrow; ventrally with a single, wide, short, prosternite between legs. Mesothorax paler than prothorax; setal areas nearly merged; posterior black margin extending along lateral margin nearly to anterior margin; ventral area with a linear row of small, dark, mesosclerites along each side of posterior margin. Dorsal metanotal setal areas on distinct sclerites, without additional setae on metonotal membrane. Ventrally, mesosternite with very pale linear row of small sclerites along each side of posterior margin, may be difficult to see, appearing as a row of indentations. Legs typical limnephiloid form with short, stout proleg and hind leg the longest. Meso and metafemur with two, long, dark setae ventrally and a row of very small, fine spinelike setae along entire ventral setal margin. Anterior face of meso and metafemur with numerous accessory setae; posterior face usually with one or two accessory setae.

First abdominal segment with numerous long setae anterior of dorsal spacing hump; lateral spacing hump with several small sclerites on dorsal margin and one larger sclerite along posterior margin; ventrally with numerous long setae and a pair of posterior setal warts on mature larvae. Chloride epithelia present ventromesally, much wider than long ( albus 2-7 [n = 3]; antennatus 3-7 [n = 4]). Lateral fringe on segments 2-8 ( antennatus ), 3-8 ( albus ); segment 2 portion is very short. Forked lamellae absent. Gill clusters consist of single filaments dorsally on segment 2 through 5 or 6, ventrally on 2 through 5, lateral line gills absent.

Ninth tergite with 3-4 pairs of long setae and several additional shorter setae. Lateral sclerite of anal proleg without short, stout, pale setae. Anal claw with single dorsal accessory hook.

Pupal case of final instar slightly curved, non-tapered, wood and mineral, or all mineral construction. The limited larval material available indicates the earlier instars may build vegetation cases.

Pupa (Fig. 5), (n = 4 albus ). Labral setae long, with apices spirally twisted, not hooked. Mandibles triangular with apical half strongly tapered and flattened into an acute blade; mesal edge of blade slightly serrate. Antennal scape with a ventrolateral setal tuft and a single seta at the dorsal margin. Second antennal segment with a dorsal tuft. Antennae shorter than abdominal apex. Spined ridge of 1st abdominal tergite weak, linear with small scattered spines. Anterior hook plates present on abdominal tergites 3-7, with strong hooks directed posteriad. Small, oval posterior hook plates present on tergum 5. Abdominal lateral fringe present on segments 5-8. Anal processes elongate, slender, tubular, with patch of minute, dorsal spines at apex. Four long setae on each anal process; one located basally, and three apically.

Etymology.

Montiphylax from the Latin montis (mountain) and the Greek phylax (guard), referring to the mountainous habitat of this genus.

Differential diagnosis of the Montiphylax species.

The male of M. antennatus is distinguished from M. albus and M. thor by the long, narrow superior appendages in lateral view and the blunt paramere apex. The M. thor superior appendage has a wide base, appearing more triangular in lateral view. The superior appendage of M. albus is shorter than either M. antennatus or M. thor although wide at the base like M. thor . In lateral view, the paramere apex of M. albus and M. thor is acute; in M. albus the paramere apex is downturned while it is upturned in M. antennatus and M. thor .

The female of M. antennatus is separated from M. albus by the round anterior margin of the vaginal apparatus that is more quadrate in M. albus in ventral view. The female of M. thor is unknown. The pupa of only M. albus is known.

The lateral setal fringe of M. antennatus larvae originates on the posterior margin of the 2rd abdominal segment while the lateral fringe of M. albus starts at the anterior margin of the 3rd segment. The larva of M. thor is unknown.