On the Andean genus Leschenius (Coleoptera: Curculionidae: Entiminae): Updated phylogeny, with a new species from Ecuador, discovery of males, and larval description of the potato weevil Leschenius vulcanorum

Phylogenetic analysis

For the phylogenetic analysis of Leschenius, the list of morphological characters and the data matrix by del Río, Marvaldi & Lanteri (2012) were modified to include the new species as a terminal taxon as well as new information about the males of Leschenius vulcanorum and L. bifurcatus.

For the inclusion of the new species in the present analysis, four characters from the list by del Río, Marvaldi & Lanteri (2012) were redefined (chars. 5, 41, 47, and 48), and a new one for the male genitalia was added (Table 1). The new list consisted of 50 morphological characters of the adults, including 36 from the external morphology and 14 from the female (9) and male terminalia (5). The data matrix herein analyzed includes 12 terminal taxa, corresponding to seven species of Leschenius plus five outgroup taxa (Table 2) closely related to Leschenius according to Lanteri & del Río (2017). All characters were treated as non-additive and analyzed under equal weights.

A cladistic analysis was conducted with TNT v1.5 (Goloboff & Catalano, 2016), using the “traditional search” algorithm, with 100 random addition sequences, Tree Bisection and Reconnection (TBR) branch swapping, holding 10 trees during each replication. The most parsimonious tree was rooted with Melanocyphus lugubris. Clade stability was evaluated with 1000 replication Bootstrap (BT) (Felsenstein, 1985), support values over 50% were indicated below branches. The total length (L), the consistency index (CI) (Kluge & Farris, 1969), and the retention index (RI) (Farris, 1989) of the most parsimonious trees (MP tree) were calculated excluding the uninformative characters. The character changes were mapped on the tree using fast (ACCTRAN) optimization with WINCLADA1.00.08 (Nixon, 2002).

Cladistics

The analysis yielded one most parsimonious tree (L = 155 steps, CI = 0.56, RI = 0.53) (Fig. 1). In the cladogram, Asymmathetes pascoei is the sister group of Leschenius, relationship that is supported by several synapomorphies (at least 10 exclusive and one homoplastic character changes, shown in Fig. 1). Leschenius is monophyletic and includes the new species, L. ventrilingulatus, sharing the synapomorphies of the genus: the well-developed pre-epistome (character 10.1); the ‘V’–shaped pronotal base (character 17.2); the slightly prominent to absent elytral humeri (character 23.1); and the procoxae almost contiguous with anterior margin of prosternum (character 29.0). Leschenius is also supported by five homoplastic character states: antennal scape slightly exceeding posterior margin of eyes (character 12.2, with reversal to 12.1 in L. nigrans–L.manueli clade); funicle segments 2 and 1 subequal (character 13.2, with reversal to 13.1 in L. vulcanorum and L. rugicollis); elytral base straight to slightly curved backwards (character 21.1) with evolutionary transition to 21.2 in L. nigrans–L.manueli clade (apomorphic with a reversal to 21.1 in L. nigrans). The latter is an important character for Leschenius because all the other genera of the “Andean group” have the elytral base bisinuate (21.0).

The genus Leschenius has two main clades, named A and B in Fig. 1. Clade A is well supported and includes the new species, L. ventrilingulatus as sister of L. vulcanorum, a relationship supported by the very short rostrum (character 5.2), the relatively wide pronotum (character 14.1), the short cornu of spermatheca (character 44.0); the penis with its apex tapering into a long acute projection (character 47.0), dorsally slightly recurved (character 49.1), with a long flagelum like sclerotization in the endophallus (character 48.2). Clade B includes the remaining five species of the genus, supported by the rostral sulcus exceeding posterior margin of eyes (character 7.1), corbel of metatibial apex narrow, setose or denuded (character 31.2); penis apodemes half as long as penis body (character 45.1), and by some homoplastic characters such as medium sized body (character 0.1), sides of rostrum slightly convergent towards apex (character 6.0), and presence of apical projection of elytra (character 24.1). In clade B, L. bifurcatus is the sister group of the remaining species, which form a clade defined by the elytral base strongly curved backwards (character 21.2) and by the homoplastic characters: antennal scape reaching posterior margin of eye (character 12.1), pronotum slightly conical (character 15.1) with lateral angles projected in males (character 18.1), and humeral angle of males anteriorly projected (character 22.1). They are grouped in two sister subclades, one including L. nigrans and L. silviae, defined by one synapomorphy, the obtuse angle between the longitudinal axis of penis and its apodemes (character 46.1), and four homoplastic character states: funicle segment 2 more than 1.5 times longer than segment 1 (character 13.0), maximum width of elytra at anterior third (character 20.2), apical comb of metatibiae longer than dorsal comb (character 32.0), and blunt posterior margin of ventrite 5 in males (character 35.3). The other subclade includes L. rugicollis and L. manueli and is supported by two synapomorphies, strongly convex eyes (character 11.0), and apex of median lobe evenly rounded (character 47.3), plus three homoplastic character states, the rostrum and forehead coarsely strigose (character 3.3), pronotum foveolate-granulose (character 4.2), and penis apodemes slightly shorter than penis body (character 45.0).

Taxonomy

Most characters of the following larval description, based on specimens of L. vulcanorum, may apply to the genus Leschenius. Terminology as in Marvaldi (1998).

Description of larvae. Mature larva. Body robust, widest at thorax and first abdominal segments. Cuticle asperities present on ventral areas and absent on lateral and dorsal areas. Head (Fig. 2A). Deeply retracted into thorax, longer than wide; posterior margin ogival; posterior half unpigmented, with softer integument and without setae; all setae shifted anteriorly, placed on anterior third. Epicranial line more than 0.5 x the length of head capsule. Frontal lines and endocarina absent. Hypopharyngeal bracon with paramedian maculae. Postoccipital condyles obtuse, hyaline. Setae (Fig. 2A): fs4,5, des5, and les2 long, subequal situated on anterior cephalic fifth; des1, des3 shorter but well developed; fs1,2,3, des4, pes1-4 minute; les1 reduced; vcs1 longer than vcs2, both short. Stemmata absent. Antenna (Fig. 2B) with sensorium about 2.5 x wider than long, truncate at apex. Labrum (Fig. 2C) with lms1,2,3, subequal, lms1 slightly less widely separated than lms2. Epipharynx (Fig. 2D) with mes1 less separated than mes2; epipharyngeal sensilla as single units (not as sensillum clusters), one pair between mes1 and mes2 but closer to mes2, and another pair close to bases of labral rods; labral rods (Fig. 2D) ax shaped, bifurcate, with one arm reaching mes1 and the other mes2. Mandibles (Fig. 2E) with mds1 slightly longer than mds2, both transversely placed within the scrobe; mds2 exterior and slightly basal to mds1. Maxillae (Figs. 2F–2G) with spinules on dorsal surface of external margin of stipes and below mala and palpus; maxillary mala with a row of eight dms and with four vms. Labium (Fig. 2F) with premental sclerite well sclerotized, with posterior extension truncate and expanded at apex, anterior extension slender. Thorax (Fig. 3A). Spiracle (Fig. 3E) ellipsoidal, without airtubes. Pronotum (Fig. 3A) with nine setae. Meso- and metathorax with pds3 distinctly longer than others; alar area with two as. Pedal areas of thoracic segments (Figs. 3A–3B) each with nine setae: seta z conspicuous; setae x and y subequal; u smaller than v; v smaller than w; seta v’ present and rather conspicuous; small x’ distinct; a pair of additional anterosternal microsetae occasionally present in front of each pedal area. Abdomen (Figs. 3A, Figs. 3C–3D): Spiracles (Fig. 3E) elliptical, 2x smaller than thoracic one, without airtubes. Segments AI-VII (Figs. 3A, 3C) with five pds, pds3 and pds5 the longest; spiracular area with only ss2 distinct and progressively placed closer to postdorsum, ss1 vestigial or absent. AVIII with four pds, lacking the homologous pds2 of preceding segments; ss indistinct. Abdominal apex (Fig. 3D) modified, with transverse posterior sclerotized ridges on dorsum, pleura and sternum of AIX; AIX with four ds including a seta ds’, placed lateral to ds1; laterally with two ls strongly unequal, the longest on sclerotized ridge; AX terminal, four-lobed, each lateral anal lobe with three minute setae, the outermost larger.

First instar larva (Figs. 2H–2J, 3F). Head (Figs. 2H–2I) only slightly retracted into thorax, slightly longer than wide; major cephalic setae placed on anterior half, des2 and les1 less reduced than in older larvae; des1 minute (smaller than in mature larvae). Frontal lines weakly distinct. Anterior and posterior stemmata distinct, as dark pigmented spots. Antennal sensorium prominent and projected outwards. Mandibles (Fig. 2J) with mds1,2 strongly unequal, mds1 about 5x longer than mds2. Thorax. Spiracle (Fig. 3F) bicameral with annulated airtubes; pedal area with setae z, and v’ relatively small, seta w relatively very long and spatulate or blunt at apex. Abdomen. Spiracles (Fig. 3F) bicameral, with airtubes having a smaller number of rings than thoracic one; abdominal apex not distinctly sclerotized.

Remarks. The characters mentioned above for the first larva, newly hatched, are exclusive of the first instar (see also Marvaldi & Loiácono, 1994). Additional differences between early and older instar larvae involve relative dimension of structures, like the antennal sensorium, which are relatively much larger in the first instar; the pigmentation and level of sclerotization of body areas tend to increase in successive instars; there are larger differences in length between setae of different body areas in early instars.

Comparative notes. The larval characters given herein for the genus Leschenius are in full agreement with those defining the tribe Naupactini (Marvaldi & Loiácono, 1994) or Naupactus and allied genera (Marvaldi, 1998). Two apparently distinct features of the mature larva studied of L. vulcanorum are the head capsule with des1 well developed (in known mature larvae of other Naupactini des1 is minute or very small); also, setae x and y of pedal areas of thoracic segments are subequal (in other Naupactini as Naupactus, seta x is distinctly smaller than y). Larval characters deemed as diagnostic for the species are given below.

Notes on type material. Four paratypes of the species of Leschenius described in del Río, Marvaldi & Lanteri (2012) were finally deposited in the MLPC instead of the collection mentioned in the original publication: one paratype of L. bifurcatus del Río, Marvaldi & Lanteri, with labels ‘ECUADOR, PICHINCHA, POMASQUI, RUNICUCHO, 2400 m, 6–XII–1993, K. Volbracht’; two paratypes of L. manueli del Río, Marvaldi & Lanteri, with labels ECUADOR, AZUAY, VIA CUENCA LOJA, 5 km DE ONA, 13–I–1997, A. Paucar’; and one paratype of L. silviae del Río, Marvaldi & Lanteri, with label ‘Cuenca Jesta’.

Diagnosis and description of female in del Río, Marvaldi & Lanteri (2012). Description of male (Fig. 5A). Smaller than female (4.0–6.3 mm; females 5.3–8.7 mm); rostrum shorter (L/Wa: 0.76–0.84); less convergent towards apex (Wb/Wa, 1.15–1.30); antennal club more elongate (L/W, 2.5–2.8); pronotum (W/L: 1.25–1.35), wider than the elytra and longer than in females, with sides more arcuate; elytra slightly shorter (L/W, 1.32–1.40) with apex not divided, more rounded; metatibiae with larger mucro than in females; posterior margin of ventrite 5 blunt. Genitalia (Figs. 6G, 6K). Median lobe slightly curved in lateral view, tapering towards apex, with subacute, dorsad slightly recurved hook-like apex; penis as long as abdomen; apodemes slightly shorter than median lobe (0.7×); endophallus armed with minute spicules and with a slightly sclerotized flagellum.

Larval stage. One mature larva and four submature larvae, as well as associated adults of L. vulcanorum, were collected from the following locality: Colombia, Municipio de Sibaté, vereda el Romeral, 4°26′3″N, 74°14′8″O (3100 masl), J.E.C. Gomez leg., 2009. Additionally, 10 first instar larvae were obtained from eggs deposited by some of the collected adults kept in captivity. After comparison with larvae known for other species in tribe Naupactini (Marvaldi & Loiácono, 1994; Marvaldi, 1998) the following combination of characters can be suggested as diagnostic for the species L. vulcanorum.

Mature larva (Figs. 2G, 3A–3E). Maximum head width 2.2 mm. Setae fine, brown. Head yellowish, intense yellow on anterior margin of frons, about 1.3× longer than wide. Cephalic setae (Fig. 2A): des1 well developed (although shorter than des3 and those placed on anterior third, fs4, fs5, des5, and les2). Ephipharynx with spinules anteriad and posteriad to the labral rods; epipharyngeal sensilla not in clusters but apparently fused into single units. Pronotum pigmented with pattern of brownish maculae (Fig. 3A). Abdominal apex (AIX) with transverse sclerotized ridges in dorsum, pleura and sternum (Fig. 3D).

Larva 1 (Figs. 2H–2J, 3F). Maximum head width 0.2 mm. Head (Fig. 2A) with des1 minute (like des 4), cephalic setae well developed are des2, des3, des5, fs4, fs5, les1, and les2; des1 slightly more widely separated than fs4. Clypeus with setae subequal. Labrum with lms2 somewhat more widely separated than lms1.

Type material examined. Lectotype of Canephorus vulcanorum Kirsch, female, Ecuador Tunguragua, 3800, Canephorus vulcanorum typus Kirsch, MTD, (Fig. 4A), here designated. Paralectotype of Canephorus vulcanorum, Ecuador, Sangay, 3500m, cotypus, MTD. Lectotype of Amphideritus brevis Oliff, female, Ecuador feet, Ed. Whymper, MNHN, here designated (Fig. 4B). Lectotype of Amphideritus pigmaeus Oliff, female, Chimborazo, Ecuador, 12-13000 ft, Ed Whymper, MNHN, here designated (Fig. 4C). Lectotype of Caulostrophus aequatorialis Kirsch, female, Cotopaxi, 5688, Typus, MTD, here designated (Fig. 4D).

Other material examined. COLOMBIA. No loc., int. Miami, 5-2-85, with cut flowers of Dianthus sp. (1f USNM). ECUADOR. No loc., 11-11-93 (2f USNM). Chimborazo: Chimborazo, S side of Mt, elev 11600 nr Snowline, 19 june 1975 (1f USNM); Colta, 3-VI-05, Ohaus, 9-VII-05 (27f ZMB); Interandin-Hochland, Colta 3500–4000 m, 8-10-VII-1905 Ohaus (1f ZMB), 2,8-VII-1905 Ohaus (2f ZMB); Faldas del Chimborazo, jan-1983, in pine leaves Pinus radiata, adults feed, Lopez col (1f USNM); Guamote, 3-7-1969, en cocoons of alfalfa plants (1f USNM); Guaslam prov, 1-22-60-on bucts of young corn, Merino (2f USNM); Quimiag on maize, Jan 1979 Kirckhy (2f BMNH); Riobamba, 3-VII-1905, unter steinen, Ohaus (17f ZMB), 20-XI-05 (1f ZMB), 27-XI-05 (2f ZMB); Riobamba, Ause de Cubillin, 3500, 5-Vii-05 Ohaus (42f ZMB). Cotopaxi: 71 km W Latacunga under stones May 1, 1978, O’Brien & Marshall (1f 1m MLP; 45 km W Latacunga, under stones May1 1978, O’Brien & Marshall (8f MLPC); 21 km S Latacunga, April 25 1978, CW&L O’Brien & Marshall (1f MLP); 6 km W Latacunga, under stones, May1 1978, O’Brien & Marshall (3f MLP); Latacunga, XI 1981 Onore Brit Mus 1990-214 (1f BMNH); 15 km W entrance PN Cotopaxi, April 30 1978, O’Brien & Marshall (4f MLP); 14 km W entrance PN Cotopaxi, April 30 1978, O’Brien & Marshall (1f MLP); Cotopaxi, P. 13 km S Latacunga along PanAma, XI-3-77, G Noonan, M. Moffett, under clumps soil and grass, rocks, debris-in green grassy field w green short grass ca 2600 m. (13f 1m MLP); Tilipulo, V-III-1981, G. Onore Brit Mus 1985-254 (4f BMNH). Bolívar: Guaranda, X-I-1955, on new corn (7f USNM). Loja. Loja, Ohaus (2f ZMB). Pichincha: 38.8 km NE Quito on PanAm XI-8-77, G Noonan, M. Moffett, under rocks on dirt clumps, in areas with sparse to very sparce short grass ca 2200 m. (1f MLP). Tungurahua: SE end Ambato, XI-1-77, G Noonan, M. Moffett, under rock in fields w short sparce grass, soil dry under stones, ca 2500 m. (2f MLP); 13 km NE Baños, April 26 1978, O’Brien & Marshall (1f MLP); Baños, 1800 m, 9-V-37 Brundage (2f USNM); Baños, X-4-44, EJ Hambleton (1f USNM); Pomasqui, E = 0, Merino, orange trees (4f USNM); Totoras, 7 km SE Ambato, April 26 1978, O’Brien & Marshall (3f MLP). Plus, the material listed in del Río, Marvaldi & Lanteri (2012).

Remarks. In the revision of the genus Leschenius (del Río, Marvaldi & Lanteri, 2012), the type material of the species Asymmathetes aequatorialis (Kirsch) was not seen and we mentioned that this species may also belong to the genus Leschenius. Herein, based on the observation of the type material of all the names related to Leschenius vulcanorum (Figs. 4A–4D), including Caulostrophus aequatorialis Kirsch (Fig. 4D), we establish the synonymy of this name with L. vulcanorum (Fig. 4A). This species is only known from the type material and corresponds to a phenotype within the great variation observed in L. vulcanorum (see Figs. 4A–4D).

Bisexual populations of L. vulcanorum have been so far only seen in Ecuador, near Latacunga locality (Cotopaxi province), and in Ambato locality (Tungurahua province) (Fig. 7). Differences noted between the bisexual and the parthenogenetic populations are related with the body size and morphometrics of the elytra. The bisexual form is usually smaller with slightly shorter elytra.

Host plants. Leschenius vulcanorum was found in association with cabbage Brassica oleracea L. (Brassicaceae), alfalfa Medicago sativa L. (Fabaceae), young corn Zea mays L. (Poaceae), pine Pinus radiata D. Don, orange trees, and with cut flowers of carnation Dianthus sp. It is considered an important pest of potato Solanum tuberosum L. (Solanaceae) in Colombia, and is known as ‘potato shooter’ (del Río, Marvaldi & Lanteri, 2012).

Diagnosis. Leschenius ventrilingulatus is easily distinguished from the remaining species of Leschenius (except L. vulcanorum) by possessing a shorter and less conical rostrum with sides not thickened and elevated, and apex not projected. It is very similar to L. vulcanorum, but distinguished by its size usually small, vestiture of denser and thicker setae (mainly on head, legs and elytra), shorter antennae (with funicular segments 1 and 2 subequal); shape of the pronotum, subcylindrical with anterior margin as wide as posterior margin; elytra shorter (about 1.5×longer than wide at base; 2×in L. vulcanorum); the metatibial apex with narrow corbel; female with ventrite 4 with a posterior rounded projection; and posterior margin of ventrite 5 subacute, not excavated. Female genitalia with plate of sternite VIII sub-rhomboidal, not elongate, with longer apodeme.

Description. Female (Figs. 5B, 5D–5F). Species medium-sized (LB, 5.0–6.0 mm). Tegument visible, dark brown to reddish brown, shiny. Vestiture composed of disperse, pale ocher to cream colored setae, moderately dense, cream-colored decumbent setae-like scales, absent on middle of pronotum (forming wide lateral stripes) on pronotum, grouped on patches on elytra, in some cases devoid of scales along middle line; also present on venter and legs (more abundant on distal third of femora). Rostrum very short (Fig. 5F) (L/Wa, 0.73–0.83), sides moderately convergent towards apex (Wb/Wa, 1.31–1.43), dorsum moderately convex. Forehead foveolate–strigose, with longitudinal striae. Vertex sparsely punctate. Antennae (Fig. 6A) of medium length (LB/LA, 2.50–2.85); scape reaching to slightly exceeding posterior margin of eyes. Funicle with segment 2 about as long as segment 1, both elongated; funicle segments 3–6 slightly longer than wide, and funicle segment 7 as long as wide; club slightly fusiform (L/W, 2.3–2.4). Pronotum (Fig. 5B) slightly subcylindrical, moderately wider than long (W/L, 1.30–1.35), with anterior margin as wide as posterior margin; median groove absent. Scutellar shield subtriangular, large and wide (surrounded by elevated edges), denuded. Elytra (Figs. 5B, 5E) short (L/W, 1.23–1.33), with maximum width on anterior third, slightly convex; base slightly curved backwards on middle; intervals about twice as long as striae, flat; striae with medium-sized punctures, 9–10 slightly closer along posterior two-thirds; elytral apex acute not projected or bifurcate, entire. Legs. Procoxae much closer to anterior than posterior margin of prosternum; protibiae with medium-sized mucro, and row of acute small denticles (six or seven, on distal two-thirds of tibiae); meso- and metatibiae with small mucro and without denticles; metatibial apex with narrow corbel covered with disperse small elongate cream scales; apical and dorsal combs subequal. Abdomen (Fig. 5D). Intercoxal portion of ventrite 1 slightly broader than metacoxal cavities (1.10–1.15×); ventrite 2 longer than ventrites 3 and 4 combined (1.60×without projection; 1.10 along midline); ventrite 4 with a posterior rounded projection; posterior margin of ventrite 5 subacute, not excavated; tergites I–VII membranose. Terminalia. Sternite VIII (Figs. 6B–6C) with plate sub-rhomboidal, not elongate, with tuft of medium-sized and coarse setae, and with shorter setae on apical third; ‘V’-shaped sclerotization with lateral arms reaching two-thirds of plate, and lateral margins sclerotized; apodeme 2.8–3.0×longer than plate. Ovipositor (Figs. 6D–6E) as long as ventrites1–5; with scattered fine short setae on sides of baculi on anterior third; ventral baculi subparallel; styli wide. Spermathecal body (Fig. 6F) sub-cylindrical; collum (duct-lobe) conical, short; ramus (gland-lobe) indistinct; cornu long; spermathecal duct (Fig. 6D) short, half as long as ovipositor, or 3×the maximum width of spermatheca, membranous, moderately wide.

Male (Fig. 5C). Same size as female (4.8–5.5 mm); rostrum less conical (Wb/Wa, 1.32–1.37); antennal club more elongate (L/W, 2.6–2.7); elytra slightly more elongate (L/W, 1.30–1.35); metatibia with larger mucro than in female; ventrite 4 without posterior projection; posterior margin of ventrite 5 blunt. Genitalia (Figs. 6H, 6L). Penis (median lobe) slightly curved in lateral view, tapering towards apex, with dorsad recurved hook-like apex; penis as long as abdomen; penis apodemes slightly shorter than penis body (0.8×); endophallus armed with minute spicules and with a sclerotized flagellum, with a denticulated blade (Fig. 6H).

Morphometrics. Holotype, female: rostrum L/Wa: 0.77, Wb/Wa: 1.31; antenna LB/LA: 2.85, antennal club L/W: 2.31; pronotum W/L: 1.34; elytra L/W: 1.33; LE/LP: 2.6.

Etymology. The specific name refers to the tongue-like projection of the female venter.

Material examined. Holotype. Female, five mm long, with labels as follows “ECUADOR, Totoras,/ 7km SE. Ambato/Apr. 26, 1978 C&L/ O’Brien & Marshall” (MLPC). Paratypes. Same data as holotype (1m ASUCOB); ECUADOR, 6 km W/ Latacunga under/ stones May 1, 1978/ O’Brien & Marshall (1f, 1m MLPC, dissected with genitalia in vial with glicerine); ECUADOR/ Latacunga/ IX- 1981 Onore/ Brit. Mus./ 1990-214 (3f 2m BMNH); ECUADOR, 5km SE./ Pelileo, April/ 26, 1978 CW&LB/ O’Brien & Marshall (1m ASUCOB); ECUADOR/ Catamayo B./ Loja 5.9.05/ F. Ohaus (1f ZMB).

Geographic distribution (Fig. 7). Leschenius ventrilingulatus is endemic of Ecuador, known for Cotopaxi, Loja, and Tungurahua provinces. It is distributed on the interandean region on river basins, between 1250 and 2750 m above sea level (unlike L. vulcanorum which is distributed in higher altitudes 2600–5000 m. a. s. l.). It is sympatric with L. vulcanorum (Fig. 7) in Latacunga (Cotopaxi province) and Totoras (Tungurahua province) at 2600–2750 m. a. s. l.

Remarks. Leschenius ventrilingulatus is the sister species of L. vulcanorum, according to results of the cladistic analysis herein undertaken (Fig. 1).

Diagnosis and description of female in del Río, Marvaldi & Lanteri (2012). Description of male (Fig. 5H). Similar size as female, slightly smaller (Fig. 5G) (10–13 mm); rostrum (L/Wa, 1.0–1.1; Wb/Wa, 1.30–1.45); antennal club slightly more elongate (L/W, 3.1–3.4); pronotum (W/L, 1.17–1.19); elytra (L/W, 1.60–1.65) with projected apex but not bifurcated, only slightly divided; ventrites 3-5 not bulged as female, posterior margin of ventrite 5 blunt. Genitalia (Figs. 6I, 6J, 6M). Penis body slightly curved in lateral view, tapering towards apex (Fig. 6M), with dorsad strongly recurved hook-like apex (Fig. 6J); penis longer than abdomen (1.25–1.30); penis apodemes much shorter than median lobe (0.4×); endophallus armed with minute spicules and with two long wing-shaped sclerites (Fig. 6I).

Material examined. ECUADOR. No loc, intercept. Port Miami, 16-VI-2004 (1f USNM). Imbabura: 3.9 km N. Ibarra on Pan Am, XI-II-77, Moffet collr, under rocks by rd. in dry area, with sparce grass ca. 2300 (1f, 3m ASUCOB; 1f, 2m MLPC;); Urcuqui, 14-III-62, Merino & Vasquez, in soil nr cotton plants (2m USNM); El Chotar, Mr. Juncal, 1 june-1961, Merino & Vasquez, reared from larvae doing damage to roots of bean plants (1m USNM). Pichincha: Conocoto, 31-Jan-1992, Alvaro Barragan (1m MLPC); Pomasqui, Runicucho, 2400 m., 6 Dec-1993, E. Volbracht (1m PUCE). Plus the material listed in del Río, Marvaldi & Lanteri (2012).

Remarks. The specimens of the population from Ibarra (Imbabura) are slightly different from the type, the female (Fig. 5G) has a wider and shorter pronotum and the elytral apex only slightly bifurcated but strongly projected posteriad; the males have also a wider and shorter pronotum and the penis with a shorter ostium area and a more recurved apex (Fig. 6J).

Host plants. The larvae of L. bifurcatus were found in association with bean plants, Phaseolus vulgaris L. (Fabaceae).

Key to species of Leschenius

Modified from del Río, Marvaldi & Lanteri (2012).