Oecetis agosta, Blahnik, Roger J. & Holzenthal, Ralph W., 2014

Blahnik, Roger J. & Holzenthal, Ralph W., 2014, Review and redescription of species in the Oecetis avara group, with the description of 15 new species (Trichoptera, Leptoceridae), ZooKeys 376, pp. 1-83 : 10-12

publication ID

https://dx.doi.org/10.3897/zookeys.376.6047

publication LSID

lsid:zoobank.org:pub:2B58574A-5FCF-40D1-9A3A-FB4D13D33A92

persistent identifier

https://treatment.plazi.org/id/C87FB5D2-278A-4C7A-AEA5-75F91DFEC287

taxon LSID

lsid:zoobank.org:act:C87FB5D2-278A-4C7A-AEA5-75F91DFEC287

treatment provided by

ZooKeys by Pensoft

scientific name

Oecetis agosta
status

sp. n.

Oecetis agosta sp. n. Figs 2, 54, Map 3

Diagnosis.

This species is most readily identified by the peculiar shape of the phallobase of the male, which is distinctly bent or elbowed in the middle and has a protrud ing apex and a ventral margin that is noticeably convexly bulged before the apex. In overall morphology the genitalia are nearly intermediate between Oecetis verrucula sp. n. and Oecetis protrusa sp. n., agreeing with the former in having an inferior appendage with a very acutely angled and distinctly protruding ventral lobe, and with the latter in the general form of the phallobase, with a protruding apex and preapical convex bulge on the ventral margin. However, the dorsal lobe of the inferior appendage is broader than in Oecetis verrucula and the phallobase is much more angularly bent or elbowed in the middle than Oecetis protrusa . Additionally, unlike Oecetis protrusa , which has very large, conspicuous forewing spots, and Oecetis verrucula , which has smaller, but distinct spots, Oecetis agosta is nearly immaculate, with only the faintest trace of pigmentation at the branch points of the major veins. However, the available material for Oecetis agosta is very limited and it is impossible to assess how constant this latter character may be. Although this species is currently known from a single locality in Mexico, and from very limited material, it is distinctive enough to suggest that it should be recognized as a new species.

Adult.

Forewing length: male (7.6 mm). Color yellowish. Antennae whitish with indistinct, narrow annulations at intersection of antennomeres. Forewing spots not apparent (slight trace of pigmentation at base of discal and thyridial cells and base of fork V); veins of forewing chord narrowly spaced, s and r-m veins very close; chord very lightly, not evidently, pigmented; apical spots of forewing absent. Setae along veins in apical part of forewing mostly apically directed, a few moderately, not conspicuously, laterally diverging. Fringe of setae along costal margin of forewing dense, short, not strongly projecting.

Male genitalia.

Segment IX very short, with elongate setae along posterolateral margin. Tergum X with narrow, deflexed mesal lobe, lobe nearly uniform in width, narrowing apically, with small sensilla; lobe continuous basoventrally with projecting lateral membranous projections. Preanal appendage somewhat laterally compressed, short, length about 2 times maximum width, simple in structure, apical setae elongate. Inferior appendage with prominent, very broadly rounded dorsal lobe and angularly projecting ventral lobe; projection of ventral lobe prominent and strongly protruding, forming acute angle with dorsal lobe, angle abrupt; posterior margin of ventral lobe, as viewed ventrally (Fig. 2E), very weakly bent near base, apices of paired lobes only slightly diverging; basomesal projection of appendage prominent, rounded, with short, stiff setae; dorsal lobe with stout, mesally-curved setae on dorsal margin and stout, ventrally-curved setae on mesal surface. Phallobase moderately elongate, strongly elbowed in middle, ventral apex deflexed and very distinctly projecting, ventral margin slightly convexly bulging before apex; ventral apex, as viewed caudally, narrowly U-shaped (not keeled preapically). Phallotremal sclerite prominent, basally forming very narrow, tubular collar, ventral margin projecting and broadly rounded apically; asymmetrical lateral sclerite absent.

Holotype.

Male (pinned), MEXICO: San Luis Potosí: El Salto Falls, 23-24.vi.1965, O.S. Flint (NMNH) (UMSP000208285).

Paratypes.

MEXICO: same data as holotype, 1 male (alcohol) (NMNH).

Etymology.

This species is named Oecetis agosta , after the Greek word agostos, a bent arm, and referring to the distinctly elbowed or bent phallobase of this species.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Trichoptera

Family

Leptoceridae

Genus

Oecetis