Trachea altivolans Schaus, 1911: 96; TL: Volcano Poas [Alajuela Prov., Costa Rica]. USNM [examined].

Trachea altivolans Schaus.

Most of the autapomorphies of the tribe Apameini are based on adult genitalic morphology and were reviewed by Fibiger and Lafontaine (2005), with an updated tribal concept modified slightly through the removal of the Arzamini as a separate tribe (Lafontaine and Fibiger 2006). Nublapamea exhibits four key autapomorphies of the Apameini: ovipositor heavily sclerotized and dorsoventrally flattened, with a unique profile resembling rabbit ears when viewed ventrally; two well-sclerotized elongate platelets (sometimes termed “rods”) situated ventrally in the integument between the papillae anales; pleural sclerite of male genitalia comprising a twisted, helical ribbon (the “double helix” of Fibiger and Lafontaine (2005), although technically not double).

The morphology of Nublapamea male genitalia is unlike any other Apameini genera in that the clasper, digitus and ampulla are seemingly absent (presumably a result of the extreme reduction of these structures), combined with a very robust valve with only a slight narrowing of the neck of the cucullus. A heavily spinose ridge extends obliquely across the inner surface of the valve from the caudoventral apex of the cucullus to the dorsal edge of the costa, similar to some species of Apamea (A. verbascoides (Guenée), A. inebriata Ferguson) although with more diminutive spines. A reduction of clasper and digitus occurs also in Resapamea, but the two genera otherwise differ in most other genitalic traits and do not associate in DNA barcode sequence data. Nublapamea altivolans is among the largest New World Apameini, with a forewing length of up to 25 mm. The forewing color and pattern most closely approaches some western North American Apamea, such as A. antennata, A. centralis and A. siskiyou; however, the large, ivory-filled claviform stigma easily distinguishes Nublapamea from any Apamea. The similarity to Apamea is superficial only, as Nublapamea differs dramatically from all known species of Apamea in genitalic structure and lacks the autapomorphies of that genus (Mikkola et al. 2009; Zilli et al. 2009).

Head – Male and female antennae simple, setose-ciliate, ~68 segments, flattened ventrally and convex dorsally (D-shaped in cross-section). Eye smooth, round. Labial palpus, upcurved, first segment 0.7 × length of second segment; third segment 0.5 × length of second and directed more anteriorly. Frons evenly convex, unmodified; haustellum well developed. Thorax – Mesoscutellar crest scarcely differentiated, metascutellar tuft absent. Forewing (Figs 1, 2) – shape and pattern elements typically noctuine, most similar to Apamea antennata group; venation as illustrated in Mikkola et al. (2009) except that (R5+(R3+R4)) arises from a common stalk that is 1/3 the length of the areole, with the stalk of (R3+R4) about 1/2 the length of the areole; forewing length up to 25 mm. Hindwing – vein M2 somewhat reduced but clearly visible, originating from the bottom third of the cell. Legs – spination and proportions typically apameine: tibia lacking spines, tibial spur formula 0-2-4, epiphysis 0.6 × length of tibia; tarsus with three rows of spiniform setae on first two proximal tarsomeres; four irregular rows on distal three tarsomeres. Abdomen – Pronounced dorsal setal tufts on A2 and A3, smaller tufts on A4 and A5; male basal abdominal brushes absent. Female genitalia (Fig. 3) – Papillae anales dorsoventrally flattened, apical 2/3 rounded-triangular, base defined by a pronounced sub-basal constriction; surface moderately setose and densely microspinulose. Two elongate sclerotized plates present between papillae anales. Posterior and anterior apophyses 1.1 × and 0.7 × length of papillae anales, respectively, with slightly spatulate apices. Lamella antevaginalis well sclerotized, with a broad, round medial concavity. Ostium an irregular transverse slit, heavily microspinulose. Ductus bursae 3 × as long as wide, heavily rugose, appearing thick or slightly more sclerotized than corpus; ductus bursae joined at junction of corpus and appendix bursae on right side. Corpus bursae membranous, globose-pyriform, 2 × as long as wide, signa absent. Appendix bursae unmodified and arising posteriorly on left, approximately 1/3 size of corpus bursae. Male genitalia (Fig. 4) – Uncus of moderate length, approximately 7 × longer than medial width, laterally compressed and evenly tapering to a downcurved, blunt apex; sparsely covered with fine, long setae. Tegumen forming an offset, broad base at uncus, with rounded-triangular peniculum laterally; vinculum a rounded “V,” saccus approximately as long as wide. Juxta a trapezoidal shield, length equal to width; anellar arms not fused. Valve robust, ~3 × longer than wide, tapering only very slightly towards base of cucullus and therefore lacking a distinct subapical “neck;” ventral margin of valve evenly convex; dorsal margin essentially straight beyond base. Cucullus elongate-triangular and broad-based, corona consisting of 4–6 curved spiniform setae; inner surface of cucullus densely covered in long, straight bristle-like setae; prominent ridge extending from caudoventral point of cucullus obliquely across the inner surface of the valve to the dorsal edge of the costa, beset with > 50 long, straight spine-like setae which are directed basad. Sacculus with basal saccular process (not the clavus; Crabo et al. 2013) consisting of an angular, anvil-shaped lobe, with an additional ridge-like prominence on base of lobe; clasper scarcely discernible, a minute rounded ridge; ampulla of clasper a minute nodule bearing 5–6 setae; editum scarcely discernible as a slightly raised bump bearing 20–25 long, thin bristle-like setae; digitus absent. Aedeagus 5 × longer than wide, with slight ventrad curvature, with thin sclerotized band extending onto base of vesica and adjoining sclerotized plate of 6–7 stout, ventrally-projecting spines that are closely set and sub-parallel; vesica slightly rugose and sclerotized at base, and with a sub-basal and medial diverticulum; sub-basal diverticulum with a large tine-like spine that is directed basad; vesica length 0.8 × that of aedeagus.

Figure 1. 

Adult habitus of female Nublapamea altivolans.

Figure 2. 

Adult habitus of male Nublapamea altivolans.

Figure 3. 

Female genitalia of Nublapamea altivolans.

Figure 4. 

Male genitalia of Nublapamea altivolans.

Nublapamea is a composition derived from bosque nublado, the Latin American term for the cloud forest habitat of the type species, and Apamea, the type genus of the tribe Apameini.

Cursory examination of other Neotropical species with externally similar facies, particularly those currently placed in Trachea, Paratrachea, and Heterochroma did not reveal other potential congeners. Nublapamea altivolans in the BOLD record database (as Trachea activolans; sic) are assigned to BIN number BOLD:AAE8386 (http://v4.boldsystems.org).

The immature stages, larval biology, and host plants of Nublapamea altivolans, the sole species currently in the genus, are unknown. The ecology of most Apameini is closely linked to graminoid monocots, with the characteristic female ovipositor modified to insert eggs into various parts of the host plant, including between the leaf blade and stalk, and within seed heads. Since many apameine species are closely linked to specific graminoid hosts, it may be that Nublapamea is associated with Chusquea (Poaceae: subfamily Bambusoideae), a common graminoid of Neotropical cloud forests. Although no other apameines are known to utilize Chusquea, several North American genera are dietary specialists on Arundinaria, also a bambusoid grass (subfamily Bambusoideae). The distribution is limited to the Talamancan montane forest ecoregion of montane Costa Rica, between elevations of 1500 and 3300 m (Fig. 5).

Figure 5. 

Distribution of examined specimens of Nublapamea altivolans.