Hagenulus marshalli, Peters, J. G., Flowers, R. W., Hubbard, M. D., Domínguez, E. & Savage, H. M., 2005

Peters, J. G., Flowers, R. W., Hubbard, M. D., Domínguez, E. & Savage, H. M., 2005, New records and combinations for Neotropical Leptophlebiidae (Ephemeroptera), Zootaxa 1054, pp. 51-60 : 56-58

Hagenulus marshalli sp. n.

( Figures 3–9 )

This new species is represented by two unassociated male imagos in good condition from Ecuador. Because it represents a significant generic record for South America, it is described now even though nymphs and females are unknown. Previously, Hagenulus was believed to be restricted to the greater Antilles ( Cuba, Haiti, Jamaica and Puerto Rico).

Male imago (in alcohol). Body: 6.0– 6.5 mm, forewings 6.8–7.2 mm, hind wing 0.7 mm; foreleg 6.5–7.3 mm; cerci 12.5 mm. Head brown, dorsal portion of eyes meeting on meson of head, ocelli large. Pronotum light brown, heavily washed with blackish brown on median carina and laterally; meso­ and metanotum yellowish brown, pleural area extending anteriorly from forewing to pronotum washed with darker brown. Pro­ and mesosternum brown, mesobasisternum a little lighter, median margins of mesofurcasternal protuberances darker; metasternum heavily washed with blackish brown. Forewings: Sc brown, R a lighter brown, other longitudinal veins pale yellow­brown to hyaline, cross veins dark brown, surrounded by small blackish brown clouds in basal half of wing, clouds heaviest medially ( Fig. 3 ), membrane of costal and subcostal area pale golden brown, the color fading to hyaline throughout remainder of wing membrane. Hind wings with reduced venation, veins and membrane pale yellow­brown to hyaline ( Fig. 4–5 ); hind wings curved dorsally over scutellum ( Fig. 6 ). Legs: ratios of foreleg segments to tibia (length of tibiae 2.9–3.1 mm): femur 0.46–0.49: tarsal segments 0.03; 0.32–0.34; 0.22–0.29; 0.13–0.14; 0.06–0.07; femur of foreleg brown, faded to pale brown basally and a little darker medially; remainder of foreleg segments with tibia pale yellowish brown and tarsal segments paler, a narrow dark brown band near apex of tibia, apical third to apical half of tarsal segments 2–4 darker brown, tarsal segments 1 and 5 without color markings; other legs with light yellowish brown femora, tibiae and tarsi paler. Abdominal tergum 1 light brown with narrow blackish brown posterior margin and lateral area; terga 2–5 hyaline with short, anterior sublateral dark streaks and blackish brown posterior band extended laterally and anteriorly as in Fig. 9 ; terga 6 and 7 with similar lateral patterns, although posterior bands reduced or absent; terga 8–10 opaque, light brown, with anterior blackish brown wash on terga 8–9, tergum 10 with only anterior submedian streaks. Abdominal sterna 1 and 2 heavily washed with blackish brown, wash continuing anterolaterally and anterosubmedially to sternum 3; sterna 4–8 with light blackish brown markings anterolaterally, marks progressively reduced in size on posterior sterna; sternum 9 light yellowish brown. Genitalia: styliger plate light brown; forceps pale yellow­brown; penes light brown, divided to near base, divergent, without spines, penes somewhat twisted as in Fig. 7–8 . Cerci hyaline with blackish brown rings at articulations; median filament broken off and missing.

Etymology: species is named for G. B. Marshall who assisted C. W. and L. B. O’Brien in the collection of many aquatic insects in South America.

Material: Holotype, one male imago, Ecuador: 30 km W of Puyo, 27–IV–1978, L.B. & C. W. O’Brien; paratype, one male imago, same data as holotype. Deposited in collections of Florida A&M University.

Diagnosis: Hagenulus marshalli sp. n. can be distinguished from all other described species of Hagenulus by the following characters: 1) fork of vein MP in the forewing not symmetrical (MP2 attached to MP1 at a cross vein as in Fig. 3 ); 2) penes without spines and slightly twisted ( Fig. 7–8 ); and 3) color pattern as illustrated in Fig. 9 .

Discussion: The variation in foreleg ratios is mostly due to a relatively short third tarsal segment on one of the paratype forelegs. All forelegs were present, but only two other legs of a potential eight were found loose in the vial. The color pattern was the same on both, but it is not known if these were meso­ or metathoracic legs or to which specimen each belonged. Both are placed with the holotype. The intensity of color on abdominal segments 8–10 and on the mesosternum is lighter in the holotype than in the paratype.

In the forewings, MP2 is closely tied to MP1 by a short cross vein, not joined symmetrically as in other species of Hagenulus . Nevertheless, this species is clearly a member of the Hagenulus group of genera because of the unique shape of the hind wing, the attachment of ICu1 to CuP, and forceps typical for the genus.

Kluge (1994) treated as subgenera all members of the Hagenulus ­group from Cuba previously treated as genera by Peters (1971), including Hagenulus , Borinquena , Careospina , and Traverina , and established two new subgenera, Poecilophlebia and Turquinophlebia . One species Hagenulus (Careospina) evanescens Kluge, 1994 , has the characteristic hind wing of Hagenulus , penes somewhat similar to Hagenulus marshalli sp. n., a female with a short ovipositor, and nymphs without filter­feeding adaptations. In addition to wing characters, nymphs of the type species of Hagenulus ( H. caligatus Eaton, 1882 ) and a second Cuban species ( H. morrisonae Peters, 1971 ) have unique nymphs with filter­feeding adaptations. For this reason, Kluge (1994) removed all non­Cuban species of Hagenulus from the subgenus Hagenulus as their nymphs were not known with certainty, but he did not give them any new taxonomic placement. The same problem applies to Hagenulus marshalli sp. n., which also might represent a species of Careospina from which it would then be distinguished by the heavy coloration of the wing, the asymmetrical MP fork, and male eyes which meet dorsally. Staniczek (2003) described one new genus ( Hagenulites ) and three new species of the genus Borinquena from Dominican amber (Tertiary: Eocene to Miocene); genera and species described by Staniczek all possess a symmetrical MP fork. The asymmetrical MP fork in Hagenulus marshalli n. sp. eventually may indicate a new genus, but it seems best to delay such action until females and nymphs are known. At present, we prefer to retain described species of Hagenulus in this, the oldest genus, and to treat all of Kluge’s (1994) subgenera as genera until more extensive revisionary work is completed.

Figures

FIGURES 1 – 9. Figs. 1 – 2: Hind wings from two female paratypes of Ulmeritoides fidalgoi. Figs. 3 – 9: Hagenulus marshalli sp. n., male: 3, forewing; 4, hind wing (proportional); 5, hind wing enlarged; 6, lateral outline of head and thorax showing position of hind wing; 7, genitalia, ventral view; 8, detail of penis lobe; 9, lateral view of abdominal segments 4 – 6. Concave longitudinal veins stippled in Figs. 1 – 5.