Leptocera, OLIVIER, 1813

Buck, Matthias & Marshall, Stephen A., 2009, Revision of New World Leptocera Olivier (Diptera, Sphaeroceridae), Zootaxa 2039 (1), pp. 1-139 : 7-16

LEPTOCERA OLIVIER, 1813

Leptocera Olivier, 1813: 489 . Type species: Leptocera nigra Olivier, 1813 , monotypy.— Roháček et al., 2001: 150 (World catalog).

Lotomyia Lioy, 1864: 1116 . Type species: Limosina arcuata Macquart, 1835 [= Leptocera fontinalis ( Fallén, 1826) ], subsequent designation by Roháček, 1982: 3 (synonymy).

Paracollinella Duda, 1924: 166 . Type species: Copromyza fontinalis Fallén, 1926 , subsequent designation by Richards, 1930: 267 (synonymy).

Skottsbergia Enderlein, 1938: 650 . Type species: Skottsbergia cultellipennis Enderlein, 1938 , monotypy.— Richards, 1955: 78 (synonymy).

Diagnosis. The following characters serve to distinguish Leptocera from other genera of Limosininae : (1) Facial tubercle small to moderately developed (strongly developed in most Rachispoda ; small in most limosinine genera). (2) Scutum without well developed inclinate dorsocentral bristle near anterior margin (present in Rachispoda but relatively small in some members of R. limosa group). (3) Scutellum usually with four pairs of marginal bristles and bare disc, rarely with six pairs ( L. hexadike sp.n., Fig. 8 ), or with six pairs and 3-5 pairs of submarginal discal setulae ( L. marginata: Afrotropical, Australasian ) (two pairs in most other limosinine genera; 3-4 pairs in Rachispoda , sometimes with additional setulae or bristles on disc). (4) Mid trochanter with a strong, upcurved anteroventral bristle near apex (shared with Rachispoda , absent in other genera). (5) Mid tibia with preapical ventral bristle ( Fig. 19 : pa v; shared with Rachispoda , Pteremis Rondani and females of Pseudocollinella ; absent in other genera). (6) Mid tibia lacking apicoventral bristle (shared with Rachispoda , Pseudocollinella and Opacifrons ; present in other genera). (7) Mid basitarsus with strong ventral bristle near base ( Fig. 19 : vb; shared with Rachispoda , Pseudocollinella and Opacifrons ; absent in most genera, in rare cases bristle slightly enlarged, e.g. Sclerocoelus ). (8) Male cerci present and free from epandrium (more or less fused to epandrium and often indistinguishable in other genera). (9) Surstylus divided into anterior and posterior section (shared with Rachispoda , Phthitia and Pseudocollinella ; surstylus entire in other genera).

Description. Adults. Body length ranging from 1.6–4.1 mm in New World species. Coloration of thorax and abdomen almost completely black to brown with yellowish areas on pleuron. Pleuron entirely dull (never with shining areas), thoracic scutum dull to subshining, sometimes with distinct silvery pruinose pattern ( Fig. 7 ). Scutellum usually concolorous with thoracic scutum, in some species velvety brown ( Fig. 9 ). Head ( Figs. 2, 3 ) entirely black to brown with brownish yellow frons, face and gena. Legs blackish brown to dirty yellow. Frons with two pairs of orbital bristles and 3–4 pairs of interfrontals; ocellar, vertical and occipital bristles well developed. Ocellar bristles inserted midway between anterior and posterior ocelli. Two to four pairs of small divergent postocellar bristles present. Postverticals also small but cruciate. Lower orbital bristle usually slightly shorter than upper one, in some species groups more reduced ( L. fulva group: 0.5–0.6x as long as upper one; Fig. 3 ). Orbits with a row of mostly lateroclinate additional setulae which is continued ventrally onto the parafacials. Interfrontals becoming increasingly large anteriorly, the foremost pair cruciate and each bristle about as long as the distance between each other. Each interfrontal plate with 2(–3) minute setulae close to ptilinal suture. Facial tubercle usually not prominent, slightly developed in a few species ( L. plax group). Eye bare. Gena completely pruinose except a narrow shining stripe immediately in front of the row of postocular setae. Upcurved genal seta behind the vibrissa strong. Antenna of the usual shape found in Limosininae , arista short- to long-pubescent ( Figs. 4–6 ). Palpus usually slender, swollen in some species. Thoracic scutum ( Figs. 7–9 , 109 ) with three (rarely two) long, postsutural and 2–3 presutural dorsocentral bristles, which become gradually smaller and more hair-like anteriorly (the total number of dorsocentrals is often hard to determine since the anterior bristles are only slightly longer than surrounding hairs). Acrostichals usually in 8–10 rows at level of transverse suture (only 4–6 in L. schlingeri ); usually with 3–7 enlarged acrostichals (1–3 pairs, often plus 1-2 unpaired ones) near middle of scutum ( Fig. 109 : ac; absent in L. fulva and L. nigra groups). Prescutellar pair of acrostichals slightly to moderately enlarged. Postpronotal lobe with two bristles and one hair; upper bristle curved medially, weaker than reclinate lower one. Mesoscutum with 2+1 or 1+1 supra-alar bristles, 2+0 or 1+0 intra-alar bristles, posthumeral bristle usually well differentiated ( Fig. 109 : phu; absent in L. fulva and L. nigra groups), postalar bristles long. Scutellum with four (rarely six) pairs of marginal bristles ( Figs. 7–9 ). Disc of scutellum bare. Prosternum linear, membrane beside it in some species with 1–3 hairs on each side. Proepisternal and proepimeral hairs present but small. Katepisternum with a short anterior and a very long posterior bristle. Wings well developed ( Fig. 10 ), except in micropterous species of the L. cultellipennis subgroup ( Figs. 11–15 ). Wing membrane slightly to strongly infuscated. Costa not extending beyond R 4+5; first costal sector with long and sparse setulae (short in L. schlingeri ); second costal sector longer than third. R 2+3 sinuate, R 4+5 more or less curved up to C. Discal cell narrowed distally, angulate posteriorly and with a more or less developed process of CuA 1. M continued as a fold beyond dm-cu. Alula well developed and broad. Halteres whitish to pale brown, in micropterous species small to minute and lacking knob. Sclerites of abdomen strongly pruinose to subshining. Tergite 1+2 with anteromedial desclerotized area (in micropterous species only visible on cleared specimens). Tergites 3–5 (♂) or 3–6 (♀) with enlarged bristles in posterior corners. Micropterous species with a row of long bristles near posterior margins of tergites 2–5 ( Fig. 109 : m). Fore femur with a row of 2–6 long posterodorsal bristles and 2–3 long posteroventral bristles in distal third. Fore tibia unmodified, slender. Tarsal segments 3–5 sometimes dilated in male. Mid trochanter with a very long upcurved anteroventral bristle. Anterior surface of mid femur with a row of short erect to downcurved bristles in distal ½–2/3. Bristles of mid tibia strong ( Figs. 16–29 ); basal half with a series of three anterodorsal and 2–3(–4) posterodorsal bristles, distal posterodorsals inserted more distally than corresponding anterodorsals (in species of the L. cultellipennis subgroup the lowermost posterodorsal is usually inserted slightly below middle of tibia; Fig. 17 : l pd). Mid tibia distally with a long anterodorsal, a long dorsal and a short posterior (slightly dorsal) bristle, the former two each with 1(–2) smaller additional bristles above; distal posterior bristle with gently curved tip (in most Rachispoda this bristle is approximately as long as the anterodorsal and its tip is straight). Mid tibia with an anteroventral bristle near middle and with a strong preapical ventral bristle in both sexes. Apex of mid tibia with three anteroapical and usually two posteroapical bristles; the latter very short to long ( Figs. 18–29 ), ventral one sometimes absent ( Figs. 18, 22 : L. plax sp.n., most species of L. cultellipennis subgroup; in Rachispoda there is only one posteroapical). Mid metatarsus with a strong ventral bristle near base. Hind tibia sometimes with a slightly enlarged, somewhat bristle-like preapical dorsal hair (conspicuous in L. hexadike sp.n.).

Male terminalia: Sternite 5 (e.g., Fig. 41 ) well developed and variously modified. Posteromedial desclerotized area small to large, usually with dense microtrichia. Posterior margin usually with enlarged scales (absent in L. fontinalis group, L. nigra group and some species of L. caenosa group). Sternites 6, 7 and 8 fused to form one sclerite. Sternite 8 separate from epandrium by distinct suture ( L. plax sp.n., L. fontinalis group, L. nigra group) or completely fused. Epandrium usually saddle-shaped ( Figs. 38, 39 ), sometimes shield-like ( L. fulva group; Figs. 239, 240 ), ventrally not closed below anus by subanal plate, ventrolaterally at least with one (usually several) strong bristle(s). Hypandrium ψ- shaped; anterior apodeme well developed and long; posterolateral arms fused to anteroventral corners of epandrium; posteromedial arm distally with two smaller processes that articulate with the postgonites. Surstylus bipartite (e.g., Fig. 38 ), with the two sections closely adjoined but completely separate. Anterior section with anteroventrally directed anterior process (anterior process, Fig. 38 : aps) and lobe-like or depressed posterior part (ventral lobe, Fig. 38 : vls); the latter usually with short hairs and 1–2 long posterior bristles (rarely with numerous long bristles), sometimes divided into two parts by a median notch ( L. cymatonota subgroup, L. neovomerata sp.n.); anterior process long and slender to broad and short (greatly reduced in L. nigra group), usually lacking setae except for a row of short basal hairs along posterior margin. Posterior section of surstylus ( Fig. 38 : pss) of variable shape depending on species group, usually with 1–3 thickened, stout bristles near apex (tiny in L. plax group, absent in L. nigra group), base more or less fused through weakly sclerotized area to epandrium (completely separate in L. plax sp.n.). Cercus varies according to species group: simple and pad-like in L. caenosa group ( Fig. 39 ), L. plax group ( Fig. 281 ) and L. schlingeri ( Fig. 306 ), comma-shaped in L. fontinalis group ( Fig. 170 ) and L. nigra group ( Fig. 273 ), very long and slender, sometimes bifurcate, in L. fulva group ( Figs. 232 , 260 ). Subepandrial sclerite of variable shape (e.g., Figs. 30, 31 , 297 ), horizontal or vertical with anterior and posterior arms; posterior arms connected to base of posterior section of surstylus. Aedeagal complex ( Fig. 33 ) with phallapodeme well developed, broad and straight, articulated with base of postgonites. Postgonites usually bare (devoid of microtrichia, except in L. schlingeri and possibly other species), fused to each other anterobasally ( Fig. 35 : bcp), enveloping base of distiphallus ventrally and laterally; usually with variously shaped posterior projection at base; shanks elongate, with more or less blunt or rarely tapered apex, often gently curved anteriorly in distal half; posterior surface of shanks with three sensilla. Pregonite extremely reduced (absent in some species?), only visible when aedeagal complex is separated from hypandrium. Ejaculatory apodeme relatively well developed, oblong, with a more strongly sclerotized capitellum anteriorly; disc weakly sclerotized, with four sensilla. Aedeagus of simple structure. Basiphallus short, in cross section rectangular or U-shaped. Posterior part of distiphallus membranous, microtrichose and complanate; anterior part also membranous but with curved medial sclerotized portion.

Female terminalia (e.g., Figs. 42–44 ): Tergite 7 usually flat in longitudinal axis, sometimes convex and with narrow shining central stripe (many species of L. caenosa group, e.g., Fig. 73 ), lateral margins always narrowly shining; disc usually with some more or less enlarged bristles, these bristles usually conspicuous and cruciate in L. caenosa group ( Fig. 42 : cb). Tergite 8 divided into two lateral plates, anterolaterally with shining margin. Cerci always more or less fused to tergite 10 in New World species, the resulting sclerite circular to oblong, more or less membranous to well sclerotized. Sternite 7 usually with straight posterior margin, medially sometimes weakly emarginate ( Fig. 238 ) or protruding ( Figs. 217 , 289 ). Hind margin sometimes narrowly thickened, forming a shining rim. Sternite 8 triangular to trapezoid, lateral margins sometimes convex, posterolaterally with a pair of triangular to parallel-sided flaps (missing in L. cultellipennis and L. nigra group), which can be folded up in most species. Sternite 10 weakly sclerotized, divided medially by a membranous strip. Internally with three spermathecae and very faint spectacles-shaped sclerite. Spermatheca of variable shape, spherical to elongate, in New World species always with at least a few spiculiform processes (very short and more tuberculate in L. nigra ). Surface of spermatheca finely striate or bumpy. Paired accessory glands were observed in several species (similar to those found in Rachispoda , e.g., Roháček, 1991: Fig. 74 ).

Immature stages. The preimaginal stages of the vast majority of species are unknown. Fredeen & Taylor (1964) described all stages of L. caenosa, Roháček (1982) illustrated the egg of the Palaearctic L. oldenbergi (Duda) , and Okely (1974) illustrated the puparia of L. oldenbergi and L. fontinalis .

Discussion of morphology. (1) Male cercus. Roháček (1982) introduced the term “pseudocercus” for the conspicuous and uniquely formed cercus-like structures of the male terminalia of Leptocera (s.l.). Wheeler (1995) criticized the term and suggested that the pseudocerci were “probably entirely derived from the cerci”. We agree with this assessment based on the following observations. The Guelph Collection (DEBU) has a gynandromorph specimen of L. nigra ( South Africa, Natal, 75 km WSW Eastcourt Cathedral Peaks For. Sta., 1,400 m, 7–31.xii.1979, veld pasture, mini-dung traps, S. & J. Peck) that possesses female terminalia except for the left cercus which is replaced by a perfectly formed male cercus. The male cercus is not fused to the female tergite 10 (contrary to the female cercus on the right side). In front of the male cercus there is an additional, small, slender, bristly process of uncertain homology. Based on the unequivocal positional homology we are convinced that the male cercus is actually formed from cercal tissues during ontogeny. In the present work we are therefore using the term “cercus” rather than “pseudocercus”. Wheeler (1995) expressed doubt about the homology of the cerci of Leptocera and Rachispoda and introduced the term “ventral epandrial lobe” for the latter. Wheeler argued that “the ventral epandrial lobes [= cerci] in Leptocera are separate from the epandrium, posteromedial to the surstyli and bacilliform sclerites, and probably derived entirely from the cerci, whereas in Rachispoda they are lateral to the surstyli and bacilliform sclerites and probably partially derived from the epandrium”. We disagree with the latter observation. In many Rachispoda (e.g., in the R. fuscipennis group) the cercus is clearly demarcated by an internal sulcus (sometimes accompanied by an external crease) from the epandrium (e.g., Roháček 1991: Figs. 417, 418). This sulcus is depicted in drawings by Roháček (1991) but was not shown in the more schematic illustrations by Wheeler (1995) and Wheeler & Marshall (1995) (e.g., compare Roháček 1991: Figs. 418, 252 with Wheeler, 1995: Figs. 106 , 146 , showing the same species). Based on the course of this sulcus it is obvious that the cerci of Rachispoda are greatly enlarged, encompassing the whole posteroventral surface of the male hypopygium, touching (or almost touching) each other at the midline, and extending all the way to the lateral surface, thus more or less forming a lateral shield over the base of the posterior section of the surstylus. The sulcus shows various degrees of reduction within Rachispoda from absence of the medial portion (e.g., in R. limosa (Fallén) : Roháček 1991: Fig. 252 ) to complete obliteration (e.g., in R. brevior (Roháček) : Roháček 1991: Fig. 153 ).

(2) Postgonites. As described above the postgonites of Leptocera are fused to each other at the base forming a single functional unit ( Figs. 35 , 207 , 227 , 270 , 301 ). This has not previously been mentioned in the literature but Roháček (1991) reported a basal as well as a distal fusion of the postgonites in Rachispoda octisetosa (Becker) . We also observed a basal (but not distal) fusion of the postgonites in an unidentified Nearctic member of the Rachispoda lutosa group, while two species of the R. limosa group ( R. limosa , R. cryptistyla Wheeler ) appear to have the postgonites either narrowly separated or indistinctly fused (through pale cuticle). It is possible that fusion has been overlooked in other genera because postgonites are usually illustrated in lateral view, which does not reveal this condition. We believe that the fused condition occurs only in Leptocera and Rachispoda since species of the following genera related to Leptocera (s.l.) have separate postgonites: Phthitia plumosula (Rondani) , Pseudocollinella humida (Haliday) , Opacifrons bisecta (Malloch) and O. quarta Marshall & Langstaff.

Monophyly. The genus Leptocera s.l. (sensu Papp, 1984: with Leptocera s.str. and Rachispoda as subgenera) is a well supported monophyletic group defined by the following apomorphic characters (see Roháček, 1991): (1) presence of four pairs of scutellar bristles (some apomorphic groups with three or more than four pairs), (2) enlarged anteroventral mesotrochanteral bristle, (3) 4–6 pairs of dorsocentral bristles (groundplan number probably five, some apomorphic taxa with only three pairs), and (4) “pseudocerci characteristically developed” [according to the transformation series proposed below this should be emended to: cerci not forming subanal plate continuous with epandrium]. Other characters mentioned by Roháček (1991: 113) are probably not apomorphic or are based on wrong observations: The division of the surstylus into an anterior and a posterior section is plesiomorphic (shared with related genera Phthitia , Pseudocollinella ). The shape of the surstylus is so variable in Leptocera (s.str.) that we cannot find any synapomorphies between Leptocera (s.str.) and Rachispoda . Another doubtful synapomorphy is the divided tergite 8 with ventral appendage ( Fig. 44 : vap), which occurs in very similar form in Pseudocollinella (see Marshall & Smith, 1993).

The monophyly of Leptocera (s.str.) was first proposed by Roháček (1991). Wheeler (1995) accepted Roháček’s view and elevated Rachispoda and Leptocera (s.str.) to genus level without further discussion of the defining characters of the latter. While the monophyly of Rachispoda is well supported (see Roháček, 1991, Wheeler, 1995) the monophyly of Leptocera remains doubtful. Roháček (1991: Fig. 536) argued for a monophyletic Leptocera (s.str.) on the basis of two putative synapomorphies: (1) bare postgonite, and (2) cercus separate from epandrium. Both characters are highly problematic, and we were unable to find any additional synapomorphies. (1) In Rachispoda the postgonite usually (always?) bears a few anterior setulae and its surface is more or less covered in microtrichia (varying from very hairy to completely bare: compare Figs. 254 , 463 in Roháček, 1991). In Leptocera microtrichia are usually absent (except in L. schlingeri , see Fig. 33 ; possibly overlooked in other species?) but posterior setulae or sensilla are present in all species groups (confirmed in L. fontinalis , L. cymatonota sp.n., L. fulva , L. ellipsipennis , L. plax sp.n., L. schlingeri , L. marginata , L. sterniloba Roháček ). Their presence can easily be overlooked because the setulae are often very small or reduced to pore-like sensilla. Related genera such as Phthitia and Pseudocollinella (see Marshall & Smith, 1992, 1993; Roháček, 1985) show conditions that are similar to Leptocera . We therefore conclude (a) that postgonites of Leptocera are not bare as stated by Roháček (1991), and (b) that their vestiture does not show any obvious apomorphic conditions. (2) The morphology of the male cercus is of great relevance for the phylogeny of Leptocera (s.l.). Unlike Roháček (1991) we are not convinced that the cercus of Leptocera (s.str.) is more derived than in Rachispoda . Firstly, the base of the cercus of Rachispoda is greatly expanded so that it embraces the base of the surstylus posteriorly and laterally. This condition is unique and clearly derived. Secondly, in many (most?) Rachispoda the cercus is delimited from the epandrium by a complete, strong sulcus. We are unaware of any other limosinine genera with a similar sulcus. However, some illustrations in previous works have overemphasized the boundary between the cercus and the epandrium (e.g., Phthitia plumosula in Roháček, 1985: Fig. 879), thus suggesting the presence of such a sulcus in these species. We examined several species in which a sulcus could be inferred but invariably found that there was no trace of a sulcus. In all these cases the cercus was merely differentiated by slight differences in colour and/or texture from the epandrium. Based on outgroup comparison we conclude that the sulcus of Rachispoda is an apomorphic structure. We see only one plausible explanation for such a sulcus to be formed: through fusion of to previously separate sclerites (i.e. cercus and epandrium). Since the sulcus does not seem to provide any functional benefits a de novo formation from a state similar to the outgroups, e.g. Phthitia (where cercus and epandrium are fused almost indistinguishably to each other) appears highly unlikely. Based on these considerations we interpret the separate cercus of Leptocera (s.str.) as plesiomorphic compared to the secondarily fused condition in Rachispoda . The separate cercus is an apomorphy of Leptocera (s.l.). A third character of phylogenetic relevance is the length of the cercus. In the outgroup genera Pseudocollinella , Phthitia and Opacifrons the cercus is usually short and pad-like, though some species of Phthitia show a tendency towards elongation (former subgenera Alimosina Roháček , Collimosina Roháček , and “ Rufolimosina ” Papp). Short cerci are found in many species of Leptocera ( L. caenosa group, L. plax group, L. schlingeri , L. marginata ). The elongate and apically tapered apomorphic condition occurs in Rachispoda and the remainder of Leptocera species. At this point it is unclear whether Rachispoda + Leptocera with elongated cerci form a natural group. The shape of these elongated cerci varies greatly between species groups of Leptocera which might indicate a separate origin. An almost certain case of convergence is found in Phthitia (“ Rufolimosina ”) ornata Papp which also shows greatly elongated cerci ( Papp, 2008: Fig. 170 ; unlike Leptocera (s.str.) and Rachispoda the cerci are completely fused to the epandrium and there seems to be no sulcus).

Based on these considerations we suggest the following transformation series for the male cercus in the Leptocera genus group: (1) cercus simple and fused to the epandrium (outgroup genera), (2) cercus simple and secondarily free (primitive Leptocera ), (3) cercus free and elongate (advanced Leptocera ), and (4) cercus elongate and secondarily fused with the epandrium ( Rachispoda ). The renewed fusion in Rachispoda probably happened in conjunction with the apomorphic, lateral expansion of the cercal base. According to this phylogenetic hypothesis Leptocera (s.str.) would be paraphyletic with regard to Rachispoda . Since this new hypothesis requires further testing through a thorough quantitative phylogenetic analysis we retain Leptocera (s.str.) and Rachispoda as genera for the time being. In order to elucidate the relationships within Leptocera (s.l.) a complete phylogenetic analysis of the whole genus group ( Leptocera s.l., Pseudocollinella , Phthitia , Opacifrons ) would be required, which is beyond the scope of this revision. Because of the suspected paraphyly of Leptocera (s.str.) we are not providing a phylogenetic analysis of this group here as we had originally planned.

Relationships. Pending future analysis we tentatively consider Pseudocollinella the sister group of Leptocera (s.l.) based on the apomorphic ventropreapical bristle of the mid tibia (in Pseudocollinella only developed in females). This character is nearly unique in Limosininae , and occurs otherwise only in Pteremis . Marshall & Smith (1993) hypothesized that the sister group of Pseudocollinella was Phthitia , not Leptocera (s.l.), based on three putative synapomorphies: (1) reduction of postvertical bristles, (2) three dorsocentral bristles, and (3) spine-like apical bristle of female cercus. An alternative interpretation is that character (2) merely represents an intermediate stage in the evolutionary series from two to five dorsocentral bristles (a multistate character, see also Roháček, 1991) and character (3) is convergent (both genera include species with simple, hair-like cercal bristles). This leaves only character (1), but postvertical bristle reduction occurs repeatedly in Limosininae , and is therefore more likely to occur as a homoplasy than the (nearly) unique ventropreapical bristle of the mid tibia. Phthitia + ( Leptocera s.l. + Pseudocollinella ) form a well supported monophyletic group based on the divided surstylus, small and simple female sternite 8, and the presence of at least three dorsocentral bristles ( Roháček, 1991).

Figures

FIGURE 109. Leptocera parallelipennis sp.n., holotype male (Juan Fernández Is.). ac—enlarged acrostichal bristles, dc—dorsocentral bristles, m—marginal bristles, phu—posthumeral bristle.

FIGURES 7–9. Leptocera thoraces: (7) L. cymatonota sp.n. (Guatemala); (8) L. hexadike sp.n. (Costa Rica); (9) L. fulva (Belize). ad sc—additional scutellar bristles.

FIGURES 16–29. Leptocera mid tibiae and basitarsi. Mid tibia, dorsal: (16) L. neocurvinervis (Chile); (17) L. duplicata (Juan Fernández Is.). Apical half of mid tibia and basitarsus, posterior: (18) L. parallelipennis sp.n. (Juan Fernández Is.); (19) L. ellipsipennis (Juan Fernández Is.); (20) L. erythrocera (Honduras); (21) L. sphaerotheca sp.n. (Mexico); (22) L. plax sp.n. (Ecuador); (23) L. tapanti sp.n. (Costa Rica); (24) L. cymatonota sp.n. (Mexico); (25) L. parafinalis (Canada); (26) L. neofinalis sp.n. (Canada); (27) L. kanata sp.n. (Canada); (28) L. fontinalis (France); (29) L. nigra (South Africa). d ad—distal anterodorsal bristle, d d—distal dorsal bristle, d pa—dorsal posteroapical bristle, l ad—lowermost bristle of proximal anterodorsal series, l pd—lowermost bristle of proximal posterodorsal series, mv—midventral bristle, pa v—preapical ventral bristle, vb—ventrobasal bristle of basitarsus, v pa—ventral posteroapical bristle.

FIGURES 2–6. Leptocera heads and antennae. Heads of (2) L. argentinica sp.n. (Argentina); (3) L. fulva (Costa Rica). Arista and first flagellomeres of (4) L. aequilimbata (Peru); (5) L. neocurvinervis (Chile); (6) L. caenosa (U.S.A.). ad s—additional setulae on orbit, l or—lower orbital bristle, u or—upper orbital bristle.

FIGURES 10–15. Leptocera wings: (10) L. fulva (Belize); (11–12) L. ellipsipennis, showing variation (Juan Fernández Is.); (13) L. cultellipennis (Juan Fernández Is.); (14) L. parallelipennis sp.n., normal wing venation (Juan Fernández Is.); (15) ditto, aberrant venation. Scale bar 0.1 mm. Cs—costal sector.

FIGURES 38–44. Leptocera aequilimbata (38–40: Argentina, 41–44: Bolivia). Male terminalia (phallus and postgonites omitted): (38) lateral; (39) posterior; (40) ventral, right cercus omitted; (41) sternite 5. Female terminalia: (42) dorsal; (43) spermathecae; (44) ventral. aps—anterior process of anterior section of surstylus, cb—cruciate bristles, ce—cercus, cp—finger-like process of cercus, ep—epandrium, fm—field of dense microtrichia, ha—hypandrial apodeme, hy—hypandrium, lp—lamellate process of cercus, pa—phallapodeme, proc—process at base of posterior section of surstylus, pss—posterior section of surstylus, S—sternite, sc—enlarged scales, se—subepandrial sclerite, T—tergite (female tergite 8 divided into two halves), vap—ventral appendage of tergite 8, vls—ventral lobe of anterior section of surstylus.

FIGURES 239–245. Leptocera fulva (Belize, except 244: U.S.A.). Male terminalia (phallus and postgonites omitted): (239) lateral, cercus omitted; (240) posterior; (241) ventral, cerci omitted; (242) sternite 5. Female terminalia: (243) dorsal; (244) spermathecae; (245) ventral. ce—cercus.

FIGURES 280–286. Leptocera plax sp.n. (Ecuador). Male terminalia (phallus and postgonites omitted): (280) lateral; (281) posterior; (282) ventral; (283) sternite 5. Female terminalia: (284) dorsal; (285) spermathecae; (286) ventral. aps—anterior process of anterior section of surstylus; ce—cercus; cp—finger-like process of cercus; ep—epandrium; ha—hypandrial apodeme; hy—hypandrium; pa—phallapodeme; pssb—posterior section of surstylus, basal part; pssc—ditto, connection between basal and distal part; pssd—ditto, distal part; S—sternite; sc—enlarged scales; se—subepandrial sclerite; T—tergite (female tergite 8 divided into two halves); vls—ventral lobe of anterior section of surstylus.

FIGURES 305–311. Leptocera schlingeri (Peru). Male terminalia (phallus and postgonites omitted): (305) lateral; (306) posterior; (307) ventral; (308) sternite 5. Female terminalia: (309) dorsal; (310) spermathecae; (311) ventral. ce—cercus, proc—posteromedial process of anterior section of surstylus.

FIGURES 170–176. Leptocera neofinalis sp.n. (Canada). Male terminalia (phallus and postgonites omitted): (170) lateral; (171) posterior; (172) ventral; (173) sternite 5. Female terminalia: (174) dorsal; (175) spermathecae; (176) ventral. as—sclerotized anterolateral angle of surstylus, ce—cercus.

FIGURES 273–278. Leptocera nigra (273–275: Spain, 276–278: Venezuela). Male terminalia (phallus and postgonites omitted): (273) lateral; (274) posterior; (275) sternite 5. Female terminalia: (276) dorsal; (277) spermathecae; (278) sternites 7 and 8. ass—anterior section of surstylus, ce—cercus, cp—ventral process of cercus, ep—epandrium, fm—field of dense microtrichia, ha—hypandrial apodeme, pa—phallapodeme, pss—posterior section of surstylus, S—sternite, se—subepandrial sclerite, T—tergite (female tergite 8 divided into two halves).

FIGURES 232–238. Leptocera dicrofulva sp.n. (232–235: Ecuador, 236–238: Brazil). Male terminalia (phallus and postgonites omitted): (232) lateral; (233) posterior, arms of left cercus omitted; (234) ventral; (235) sternite 5. Female terminalia: (236) dorsal; (237) spermathecae; (238) ventral. aps—anterior process of anterior section of surstylus, ce—cercus, cda—dorsal arm of cercus, cva—ventral arm of cercus, ep—epandrium, fm—field of dense microtrichia, ha—hypandrial apodeme, hy—hypandrium, pa—phallapodeme, pss—posterior section of surstylus, S—sternite, sc—enlarged scales, se—subepandrial sclerite, T—tergite (female tergite 8 divided into two halves), vls—ventral lobe of anterior section of surstylus.

FIGURES 260–266. Leptocera rhadinofulva sp.n. (Argentina). Male terminalia (phallus and postgonites omitted): (260) lateral; (261) posterior, right cercus omitted; (262) ventral, cerci omitted; (263) sternite 5. Female terminalia: (264) dorsal; (265) spermathecae; (266) ventral. ce—cercus.

FIGURES 30–35. Aedeagal complex and subepandrial sclerite of Leptocera schlingeri (Peru): (30) subepandrial sclerite and posterior section of surstylus, lateral; (31) subepandrial sclerite, posterior section of surstylus and right cercus, posterior; (32) base of phallapodeme, postgonites and phallus, dorsal; (33) aedeagal complex, lateral; (34) same, posterior; (35) same, anterior. bcp—basal connection between postgonites, bp—basiphallus, ce—cercus, dp—distiphallus, ea—ejaculatory apodeme, pa—phallapodeme, pg—postgonites, pss—posterior section of surstylus.

FIGURES 297–304. Aedeagal complex and subepandrial sclerite of Leptocera plax group. Leptocera plax sp.n. (Ecuador): (297) subepandrial sclerite and posterior section of surstylus, posterior; (298) aedeagal complex, lateral; (299) ditto, dorsal; (300) ditto, posterior; (301) ditto, anterior. Leptocera tapanti sp.n. (Costa Rica), aedeagal complex: (302) lateral; (303) dorsal; (304) anterior. bcp—basal connection between postgonites, bp—basiphallus, dp—distiphallus, ea—ejaculatory apodeme, pa—phallapodeme, pg—postgonites, pss—posterior section of surstylus, se—subepandrial sclerite.

FIGURES 69–75. Leptocera gongylotheca sp.n. (Argentina). Male terminalia (phallus and postgonites omitted): (69) lateral; (70) posterior; (71) ventral; (72) sternite 5. Female terminalia: (73) dorsal; (74) spermathecae; (75) ventral. cp—finger-like process of cercus, da—desclerotized area, proc—process at base of posterior section of surstylus, sa—shining area of tergite 7.

FIGURES 211–217. Leptocera cymatonota sp.n. (Guatemala). Male terminalia (phallus and postgonites omitted): (211) lateral; (212) posterior, right cercus omitted; (213) ventral; (214) sternite 5. Female terminalia: (215) dorsal; (216) spermathecae; (217) ventral. i vls, o vls—inner and outer ventral lobes of anterior section of surstylus.

FIGURES 287–289. Leptocera posteronitens sp.n. (Guatemala), female terminalia: (287) dorsal; (288) spermathecae; (289) ventral. pp—shining posteromedial projection of sternite 7.

FIGURES 102–108. Leptocera sphaerotheca sp.n. (U.S.A., except 107: Guatemala). Male terminalia (phallus and postgonites omitted): (102) lateral; (103) posterior; (104) ventral; (105) sternite 5. Female terminalia: (106) dorsal; (107) spermathecae; (108) ventral.

FIGURES 138–146. Postgonites and aedeagal complex of Leptocera caenosa group. Postgonites of (138) L. aequilimbata (Argentina), (139) L. argentinica sp.n. (Argentina), (140) L. neocurvinervis (Chile), (141) L. erratica sp.n. (South Africa), (142) L. sphaerotheca sp.n. (U.S.A.), (143) L. ellipsipennis (Juan Fernández Is.), (144) L. parallelipennis sp.n. (Juan Fernández Is.), (145) L. cultellipennis (Juan Fernández Is.). Aedeagal complex of (146) L. duplicata (Juan Fernández Is.). bp—basiphallus, dp—distiphallus, ea—ejaculatory apodeme, pa—phallapodeme, pg—postgonites.

FIGURES 246–252. Leptocera insularum sp.n. (246–249: Puerto Rico, 250–252: Dominican Republic). Male terminalia (phallus and postgonites omitted): (246) lateral, cercus omitted; (247) posterior; (248) ventral, cerci omitted; (249) sternite 5. Female terminalia: (250) dorsal; (251) spermathecae; (252) ventral. ce—cercus, cda—dorsal arm of cercus, cva—ventral arm of cercus.

FIGURES 148–154. Leptocera angulispina sp.n. (U.S.A., except 153: Canada). Male terminalia (phallus and postgonites omitted): (148) lateral; (149) posterior; (150) ventral; (151) sternite 5. Female terminalia: (152) dorsal; (153) spermathecae; (154) ventral. aps—anterior process of anterior section of surstylus, ce—cercus, cp—ventral process of cercus, ep—epandrium, fm—field of dense microtrichia, ha—hypandrial apodeme, hy—hypandrium, pa—phallapodeme, pss—posterior section of surstylus, S—sternite, se—subepandrial sclerite, T—tergite (female tergite 8 divided into two halves), vls—ventral lobe of anterior section of surstylus.

FIGURES 199–209. Postgonites and aedeagal complex of Leptocera fontinalis group (excluding L. cymatonota subgroup). Postgonites of (199) L. angulispina sp.n. (Canada), (200) L. finalis (Canada), (201) L. kanata sp.n. (Canada), (202) L. neofinalis sp.n. (Canada), (203) L. parafinalis (Canada), (204) L. neovomerata sp.n. (U.S.A.), (205) L. tenuispina sp.n. (Canada). Aedeagal complex of L. fontinalis (Spain): (206) posterior; (207) anterior; (208) lateral; (209) dorsal. bcp—basal connection between postgonites, bp—basiphallus, dp—distiphallus, ea—ejaculatory apodeme, pa—phallapodeme, pg—postgonites.

FIGURES 225–229. Postgonites and aedeagal complex of Leptocera cymatonota subgroup. Postgonite of (225) L. hexadike sp.n. (Costa Rica). Aedeagal complex of L. cymatonota sp.n. (Guatemala): (226) posterior; (227) anterior; (228) lateral; (229) dorsal. bcp—basal connection between postgonites, bp—basiphallus, dp—distiphallus, ea—ejaculatory apodeme, pa—phallapodeme, pg—postgonites.

FIGURES 267–272. Postgonites and aedeagal complex of Leptocera fulva group. Postgonites of (267) L. dicrofulva sp.n. (Ecuador), (268) L. prolixofulva sp.n. (Venezuela). Aedeagal complex of L. fulva (Belize): (269) posterior; (270) anterior; (271) lateral; (272) dorsal. bcp—basal connection between postgonites, bp—basiphallus, dp—distiphallus, ea—ejaculatory apodeme, pa—phallapodeme, pg—postgonites.

FIGURES 253–259. Leptocera prolixofulva sp.n. (Venezuela). Male terminalia (phallus and postgonites omitted): (253) lateral; (254) posterior, right cercus omitted; (255) ventral, cerci omitted; (256) sternite 5. Female terminalia: (257) dorsal; (258) spermathecae; (259) ventral. ce—cercus.