Introduction
A study of emerging aquatic insects was conducted in 1989–1992 on a stream, Quebrada Prieta, (18°18′N; 65°47′W) in the Luquillo Mountains Experimental Rainforest, near El Verde, Puerto Rico (Masteller and Buzby Reference Masteller and Buzby1993a). Further collecting was also made during this period on Bisley Creek, a tributary of Rio Mamayes, near Sabana (18°19′N; 65°44′W) in the same area.
A preliminary analysis of the emergence of insects from Quebrada Prieta was reported by Masteller and Buzby (Reference Masteller and Buzby1993b), distinguishing two species of Hemerodromia Meigen (Diptera: Empididae), species A and species B. Both are described below, together with three additional species, present in very small numbers, which had been confused with species B.
The five species fit within the widely distributed genus Hemerodromia, as defined by Melander (Reference Melander1947) and amended by MacDonald (Reference MacDonald1998). Few species are known from Central America and the Caribbean (Smith Reference Smith1967; Cumming and Sinclair Reference Cumming and Sinclair2009): Melander (Reference Melander1928) described two species from Costa Rica and Panama, Melander (Reference Melander1947) four more from Costa Rica, and Williston (Reference Williston1896) one from the island of St. Vincent. Although the types were not examined, none of these seems to apply to our material.
Material and methods
The males are easily distinguished by genitalic characters; the females, however, are normally associated through colour patterns and geographical distribution with the corresponding male. Since nearly all our material is from emergence traps, the great majority of specimens are teneral and their colour patterns are poorly developed in both sexes. This precludes the association of the sexes, and the females remain undescribed, except in one instance. Nomenclature of genitalic structures follows MacDonald (Reference MacDonald1998). We use his designation of epandrium (tergite 9), hypandrium (sternite 9), and cercus (MacDonald Reference MacDonald1998, Figs. 1–2). We have conservatively called “median lobe” a projecting dorsal rectangular structure that arises dorsally and medially between the cerci and in our species may carry zero to four large setae; it is probably part of segments 10 (or 11). Description of the first species is more detailed, those of others stress points of difference. General habitus and body structure of all species correspond to Fig. 2 in Steyskal and Knutson (Reference Steyskal and Knutson1981). Some taxonomic use has been made in the past of the structure of the raptorial prolegs (Melander Reference Melander1947; MacDonald Reference MacDonald1998). All our species conform to the typical pattern (Steyskal and Knutson (Reference Steyskal and Knutson1981), Fig. 2) of long coxa subequal to femur and tibia. Femur with a grove into which fits the tibia to form capturing pincers; the grove is lined on both sides with 15–21 short, stout, and dark spines and generally seven long brown setae; at the base of the grove, a median spine sometimes larger than others and set on elevated process (MacDonald Reference MacDonald1998, Fig. 7).
Top and side view of male genitalia of Hemerodromia oncilla Masteller.
All material is stored in alcohol. Genitalia were macerated in potassium hydroxide (KOH) and examined in glycerol. All drawings are freehand. Measurements of body length (from anterior face of the head to tip of genitalia in natural position) were done under magnification with a camera lucida attachment. All primary types and, when available, many paratypes are deposited in the National Museum of Natural History (Smithsonian Institution) in Washington, District of Columbia, United States of America. A few paratypes of the more common species have been kept in the authors’ collections in Montreal, Québec, Canada, (Collection entomologique Ouellet-Robert, Université de Montréal) and Erie, Pennsylvania, United States of America (Tom Ridge Environmental Center). Additional nontype material is housed in the Canadian National Collection of Insects, Ottawa, Ontario, Canada.
Hemerodromia oncilla Masteller, new species
Description
Larger species, 2.8–3.2 mm in total length (front of head capsule to end of terminalia).
Male. Head nearly entirely dark brown to black, antennae yellowish infuscated, mouth parts white. Thorax mostly black dorsally and laterally; mesepisterna pale, mesepimera dark. Halteres pale. First abdominal segment with dark anterior ring, rest paler; segments 2–6 with infuscated terga, with one to two pairs of pale dots laterally; segment 7 pale.
Front legs large and raptorial as is typical of the genus. Procoxae pale, infuscated on terminal third. Protrochantera pale, darkened at base and on outer margin. Profemura with three transverse dark bands, separated by pale bands of similar width; each femur with groove on anterior margin bordered on each side by row of 18–22 short, dark spines, themselves flanked externally by series of six (inner surface) to eight (outer) long pale setae. Protibiae dark, fitting into the femoral groove to form a strong pincer-like apparatus; anterior margin with two rows of 16–18 small, dark spines; terminating in strong claw which fits into inner edge of the femur (no groove, only an interruption in the line of flanking setae). Tarsi dark. Midlegs and hindlegs mostly pale at base, darkening from terminal third of femora to tips of tarsi.
Genitalia (Figs. 1–2) dark. Median lobe rectangular and narrow terminating in four long setae. Cerci rectangular slightly downcurved, covered externally with sparse, large setae amid background of numerous smaller golden clothing setae; large ventral rounded plate extending downward beyond middle, lower border glabrous. Small glabrous flange-like projection on inner distal surface with a few large, dark setae. Epandrium forming pair of strong claspers, bearing distally row of marginal peg-like setae, series of strong spines and irregular field of setae on inner surface and subterminal upward glabrous projection. Hypandrium relatively simple encasing emergent phallus terminating in simple point (in lateral view). Basal external case-like structure covered with dense setae. Phallus simple, pointed, and eversible, covered by irregular toothed tubercles, expandable into a bulbous membranous structure, tip covered by spinules.
Female. Colour pattern similar to that of male, though generally less contrasted. Head dark as in male. Thorax dark dorsally, except humeri; metathorax entirely darkened dorsally and laterally. Ovipositor elongate as in MacDonald (Reference MacDonald1994, Fig. 27).
Material examined
HOLOTYPE, ♂, Puerto Rico, Sonadora, El Verde, Emergence trap, 21.ii.1989, coll. E.C. Masteller. ALLOTYPE, female, same data.
PARATYPES, El Verde, Quebrada Prieta, Luquillo Mountains, Carribean National Forest, 370 m, emergence trap, coll. E.C. Masteller. 75 ♂, 57 ♀, 20-23.ii.1989; 2 ♂, 5 ♀, 26.ii–10.vi.1990; 1 ♂, 9 ♀, 17.v.1991; 2 ♂, 7 ♀, 30.ix.1992. El Verde, Quebrada Prieta, Luquillo Mountains, Carribean National Forest, 370 m, Malaise trap, coll. O.S. Flint, 1 ♂, 6-12.ii.1990. Sabana, Bisley Stream #3, trib. Rio Mamayes, 280 m, emergence trap, coll. E. Masteller. 3 ♂, 27 ♀, 8.ii-12.iv.1990; 73 ♂, 242 ♀, 12.i–5.v.1991; 31 ♂, 25 ♀, 10.ii-31.vii.1992.
Remarks
The holotype, allotype, and a series of 20 male and 20 female paratypes were deposited in the Smithsonian Institution; 10 male and 10 female paratypes were retained in the Université de Montréal and the remainder in the Tom Ridge Environmental Center. This is the species referred to as Hemerodromia species A in Masteller and Buzby (Reference Masteller and Buzby1993b).
Etymology
From the common Spanish name of the Latin American Tiger Cat, Leopardus tigrinus Schreber (Mammalia: Felidae); it refers to the banded aspect of the raptorial forelegs.
Hemerodromia prieta Harper, new species
Description
Medium-size species, 2.5–2.8 mm total length.
Male. Head very dark brown, antennae and mouthparts pale. Thorax generally yellow, lateral sclerites of mesonotum and metatergum dark brown. Abdomen pale, terga 3–6 brown. Legs slightly infuscated; on forelegs, femora with a double row of ca 18–21 black spines, flanked on each side by seven to eight long setae; middle spine at base of femoral grove larger than others, but not set on process. Tooth and long seta at level of tibial spurs.
Genitalia dark brown (Figs. 3–4). Dorsal median lobe not projecting, bearing four long setae. Cerci very elegantly curved on side-view, expanding distally into downcast and recurved pointed lobe; in dorsal view, distinct terminal spine and pair of large abruptly curved, dark spines just beyond mid-length. Epandrium produced into pair of elongate claspers: at 3/4 length, expanding dorsally into flat, glabrous, triangular lobe; tip ending dorsally in acute spine, medially in flat, glabrous, rounded, and somewhat constricted inner projection; and ventrally in setose lobe. Hypandrium simple from which emerges long tubular phallus ending in membranous tube with spiny collar.
Top and side view of male genitalia of Hemerodromia prieta Harper.
Female. Unknown. The female apparently associated with this species has a long ovipositor as in MacDonald (Reference MacDonald1994, Fig. 27).
Material examined
HOLOTYPE, ♂, Puerto Rico, El Verde, Quebrada Prieta, Luquillo Mountains, Carribean National Forest, 370 m, emergence trap, 20.iii.1990, coll. E. Masteller.
PARATYPES. Same locality and collector as above. 40 ♂, 7.ii-21.xii.1990; 33 ♂, 9.i-20.xi.1991; 36 ♂, 15.i-25.vi.1992. Sabana, Bisley Stream #3, trib. Rio Mamayes, 280 m, coll. E.C. Masteller, 4 ♂, 8.ii-23.iv.1990; 6 ♂, 2.ii-14.vi.1991; 17 ♂, 24.i–24.iv.1992.
Remarks
The holotype and 20 male paratypes were deposited in the Smithsonian Institution; five male paratypes were retained in the Université de Montréal and the remainder were deposited in the Tom Ridge Environmental Center.
This is the species referred to as Hemerodromia species B by Masteller and Buzby (Reference Masteller and Buzby1993b). The ecological data is therefore applicable to it, despite the fact that a few Hemerodromia marci were mixed up in these samples. It was the commonest species at the Quebrada Prieta site.
Etymology
From the name of the valley, Quebrada Prieta (Dark Gorge), from which specimens of this species emerged.
Hemerodromia marci Masteller, new species
Description
Small species, 2.2–2.5 mm in length.
Male. Head light brown, appendages pale. Thorax pale yellow, darker dorsally (scutum and scutellum) and posteriorly (metathorax). Abdominal tergites one to six brown, rest of abdomen pale. On forelegs, 13–18 spines along femoral grove, six to seven long setae, no basal process.
Genitalia medium brown (Figs. 5–6). Cerci distinctly bilobed; upper lobe finger-like extending posteriorly, generally glabrous, except for a few stout dorsal setae, and terminal peg; lower lobe, longer, partly divided longitudinally. Main body bearing stout setae on outer surface, heavy spines at tip, and pair of large curved spines on inner surface before tip; just beyond mid-length crooked finger-like extension projecting upwards, then inwards and backwards. Epandrium forming pair of strong claspers, irregularly triangular with constriction in terminal third, terminating in three claw-like spines. Hypandrium very complex; pair of long rounded lamellae projecting downwards; dorsally, pair of lobes arise on each side, outer dorsal lobes stocky, plate-like, with a large ventral triangular projection, inner dorsal lobes narrower ending in lateral rounded projection and a median incurved spine. Phallus not extruded in our specimens. Median lobe short with two short stout setae.
Top and side view of male genitalia of Hemerodromia marci Masteller.
Female. Unknown. The female generally found together with this species has a long ovipositor as in Hemerodromia prieta, which often coexists with it.
Material examined
HOLOTYPE, ♂, Puerto Rico, Sabana, Bisley Stream #3, trib. Rio Mamayes, 280 m, 18.i.1990, coll. E.C. Masteller.
PARATYPES. Same locality and collector as above. 9 ♂, 11.ii-16.iv.1990; 12 ♂, 12.ii–8.vi.1991; 10 ♂, 24.i.-12.vi.1992.
Remarks
Holotype and 10 male paratypes were deposited in the Smithsonian Institution. Remaining paratypes were divided equally in the authors’ institutional collections. This was the second most common species at the Bisley site.
Etymology
Named in honour of Mark Masteller, the second author's son.
Hemerodromia melissa Masteller, new species
Description
Medium-size species, 2.6–3.0 mm in total length.
Male. Head brown, appendages light. Thorax yellow, darkened dorsally. Abdominal tergites 1–6 brown, others pale.
Genitalia medium brown (Figs. 7–8). Cerci long and somewhat rectangular, bearing row of four large pegs on outer top margin and terminating in downcast lobe with heavy setae and additional large peg-like setae. Between bases, flat ridge bearing pair of long setae on each side of midline and extending into rounded lobe. Epandrium forming pair of simple claspers in lateral view, extending medially and distally into sinuous hooked process. Phallus heavy, ending in flat anterior lobe flanked by pair of lateral flange-like structures.
Top and side view of male genitalia of Hemerodromia melissa Masteller.
Material examined
HOLOTYPE, ♂, Puerto Rico, Sabana, Bisley Stream #3, trib. Rio Mamayes, 280 m 12.i.1991, coll. E.C. Masteller.
PARATYPES. 2 ♂, same data as holotype.
Remarks
All types are deposited in the Smithsonian Institution.
Etymology
Named in honour of Melissa Masteller, the second author's daughter.
Hemerodromia simonis Harper, new species
Description
Small species, total length 2.3 mm.
Male. Head brown, appendages lighter. Thorax brown dorsally (scutum and scutellum) and posteriorly (metathorax). Abdominal tergites brown, segments 7–8 paler.
Profemora with double row of 18–21 black spines, flanked laterally by row of seven to eight long pale setae, stronger on inner margin.
Genitalia dark brown (Figs. 9–10). Cerci complex: short triangular forward-pointing lobe terminating in small spine; narrow upturned lobe bearing a few spines and setae; large irregular terminal section, roughly bilobed, upper lobe bearing very strong setae, lower lobe with smaller setae. Dorsally between cerci, membranous truncate median lobe bearing four long setae. Epandrium developed into pair of elongate, rectangular claspers, with small triangular extension at tip bearing a few long setae and flap-like appendage on inner ventral surface ending in downcast hook and bearing small tuft of setae. Hypandrium rather simple: base stocky covered ventrally by dense pilosity extending halfway up shaft; distally, produced upturned anterior plate and pair of long narrow posterior lobes.
Top and side view of male genitalia of Hemerodromia simonis Harper.
Female. Unknown.
Material examined
HOLOTYPE, ♂, Puerto Rico, El Verde, Quebrada Prieta, Luquillo Mountains, Caribbean National Forest, 14.ii.1992, coll. E.C. Masteller.
PARATYPE. 1♂, Sabana, Bisley Stream #3, trib. Rio Mamayes, 9.iii.1992, coll. E.C. Masteller.
Remarks
All types are deposited in the Smithsonian Institution.
Etymology
Named in honour of first author's grandson, Simon Harper-Cyr, an avid freshwater enthusiast and fisherman.
Conclusion
The discovery of five species in two streams and differences in the species composition between the streams probably indicates a rich and diverse local fauna of aquatic empidids. More collecting in Puerto Rico and other Caribbean islands will undoubtedly yield many new species. This will eventually allow the placement of the species into natural species groups, discussion of their origin and dispersal, as well as their relationship to species from Latin and North America.
Acknowledgements
This research supported Karen Buzby, who made many collections, under her United States National Science Foundation grant BSR-8811902 at the University of Puerto Rico. The second author was supported by travel grants from the Center for Energy and Environment Research, Oak Ridge Association. The authors wish to thank their respective universities, Penn State the Behrend College and Université de Montréal for lab space and facilities.
