Apiomerus pipil Dispons, 1971

Masonick, Paul & Weirauch, Christiane, 2022, Taxonomic revision of the Apiomerus maya species group (Heteroptera: Reduviidae: Harpactorinae), Zootaxa 5154 (5), pp. 537-556 : 545-546

Apiomerus pipil Dispons, 1971

Figs 1C , 2C, 2D, 2I , 3C, 3G , 4

Apiomerus pipil Dispons, 1971: 6 . Holotype: ♂, San Salvador: La Libertad; ISNB.

Apiomerus guatemalensis Dispons, 1971: 10 . Holotype: ♂, Guatemala; ISNB. Syn. nov.

Apiomerus pipil: Maldonado (1990: 7) (catalog).

Apiomerus guatemalensis: Maldonado (1990: 5) (catalog).

Revised diagnosis: Recognized by the combination of the following characteristics: (1) large size (> 14 mm in length), (2) quadrate cell weakly delineated by light coloration, (3) basal spot of connexivum 7 that is roughly twice the size of the marking on the preceding segment (from dorsal view), (4) males with V-shaped medial process of pygophore with narrowly spaced, relatively straight rami, (5) elongate basal dorsolateral sclerites of the endosoma that are paddle-shaped (constricted through their midsection) and strongly twisted apically, (6) about 26 endosomal denticles that are arranged into two longitudinal rows of about 13 pairs (proximal denticles arranged into two orderly rows).

Redescription: Male: Medium to large, 14.72–17.18 mm in length, width across humeral angles 4.44–5.30 mm (n=6). COLORATION: Mostly black; anterior pronotal lobe dark brown, posterior lobe brown ( Fig. 1C ); corium predominantly black or dark brown, only veins near forewing membrane white or pale-yellow (tan in some older specimens), quadrate cell of the corium is not completely outlined in white or pale-yellow; entire forewing membrane often brown with dark spots, sometimes bicolored with basal portion darkly pigmented and distal portion lighter; basal spot of connexivum 7 roughly twice the size of marking on the preceding segment (from dorsal view); lateral spots of abdominal sterna 3–5 white or pale-yellow (in some specimens they may be tan). STRUCTURE: Medial process of pygophore V-shaped in caudal view ( Fig. 2C–D ); rami narrowly separated and relatively straight along their length; dorsal phallothecal sclerite arrow-shaped in dorsal view, with pair of subtle rounded projections near base; apex of dorsal phallothecal sclerite slightly reflexed and shallowly notched; basal dorsolateral sclerites of endosoma elongated, paddle-shaped, constricted at middle, slightly wider towards apex, and outwardly rotated apically; dorsal surface of endosoma with about 26 denticles arranged into two longitudinal rows comprised of about 13 pairs; dorsolateral surface of endosoma with slight sclerotization near base.

Female: Large, 17.42–19.29 mm in length, width across humeral angles 5.34–5.86 mm (n=5).

Biology: Specimens have been collected between elevations of 50–1400 m. Adults are typically active from June through September.

Distribution: Apiomerus pipil ranges from southern Mexico (Chiapas) to Costa Rica.

Discussion: Dispons (1971) described A. pipil and A. guatemalensis as two different species; the former was described from a pair collected from El Salvador and the later from a singleton male from Guatemala. We here synonymize the two, giving precedence to A. pipil acting as First Reviser following Art. 24.2 of ICZN (1999).

While Szerlip (1980) did not include A. pipil as a member of the A. maya species group, the types of A. pipil bear many similarities with respect to general habitus and genitalic morphology to those of A. guatemalensis and A. venosus . The male holotype of A. pipil in particular possesses an arrow-shaped dorsal phallothecal sclerite, a pair of elongate basal dorsolateral sclerites of the endosoma, and longitudinal rows of peg-like endosomal denticles. Overall, this species is very similar to some A. venosus specimens. Apiomerus pipil tends to be slightly larger and lacks extensive white markings on the corial veins. The white or pale-yellow markings of the abdomen roughly double in size posteriorly on each successive connexivum. The rami on the pygophore are inserted much closer to one another than those of A. venosus .

In his unpublished dissertation, Szerlip (1980) gave names to two other putative new species in the A. maya species group, “ Apiomerus azteca ” and “ Apiomerus maculatus .” He concluded that A. guatemalensis was different from these based on the elongate pointed shape of its basal dorsolateral endosomal sclerites. The types of A. guatemalensis and A. pipil share many similarities with other specimens from the same region that Szerlip had identified as either “ Apiomerus azteca ” and “ Apiomerus maculatus .” We have observed plasticity in these structures however and argue that their shape is not consistent enough to warrant recognition of four distinct species.

Type material examined:

Apiomerus pipil Dispons, 1971 . Holotype : ♂, EL SALVADOR: La Libertad: San Salvador, 1-Jul-1954, J. Bechyné ( UCR _ ENT 00038053 ) ( ISNB) . Allotype: ♀, same locality, date and collector as holotype ( UCR _ ENT 00038054 ) ( ISNB) .

Apiomerus guatemalensis Dispons, 1971 . Holotype: ♂, GUATEMALA: exact locality and date unknown, Gisquière ( UCR _ ENT 00038050 ) ( ISNB); in poor condition with both antennae and the entire right foreleg missing and forewing membranes severely tattered. The total body length (including the apex of the forewings) that Dispons (1971) recorded (11 mm) is quite shorter than what we measured (14.72 mm).

Additional specimens examined: 38 ♂♂, 55 ♀♀ (see Appendix).

Figures

FIGURE 1. Dorsal habitus images of (A) A. immundus Bergroth, 1898 [♂ LECTOTYPE = UCR_ENT 00040816], (B) Apiomerus maya Dispons, 1971 [♀ = UCR_ENT 00013169, ♂ HOLOTYPE = UCR_ENT 00038047], (C) A. pipil Dispons, 1971 [♀ = AMNH_PBI 00218895, ♂ = UCR_ENT 00032865], and (D) A. venosus Stål, 1872 [♀ = UCR_ENT 00031790, ♂ = UCR_ENT 00032336]. All scale bars represent 4 mm.

FIGURE 2. (A–F) Caudal views of the pygophores (pyg) of males of the maya species group displaying the bifid medial process with rami (rm). In these taxa, the base of the medial process is greatly reduced giving the impression of the rami being inserted directly on the posterior rim of the pygophore. The rami are often broadly spaced from one another and render the medial process either V-shaped, as frequently observed in A. pipil (see C), or lyre-shaped (most male A. venosus). Figs. A– F are not to scale. (G–J) Dissected right parameres. All scale bars for Figs. G– J represent 0.25 mm.

FIGURE 3. Dorsal (A–D) and lateral (E–H) views of the aedeagus of males of the maya species group.An arrow-shaped dorsal phallothecal sclerite (dps) is commonly seen in males of these species (subconical in A. immundus). Note the paired triangular projections (tp) positioned basally on the dps of Apiomerus maya (B & F); these projections are absent in other maya group taxa. The basal dorsolateral sclerites of the endosoma (bdls) can be short and round (A. maya), moderately elongated with fine sculpturing basally (A. immundus), or greatly elongated and slightly twisted (A. pipil and A. venosus). The number of peg-like endosomal denticles (ed) aligned longitudinally along the distal dorsal lobes of the endosoma (ddl) varies across the group. In some taxa, notably A. immundus and some A. venosus, lateral sclerotizations of the endosoma (ls) may be observed along the endosoma’s proximal dorsolateral surface. All scale bars represent 0.5 mm.

FIGURE 4. Examples of intraspecific polychromatism across ranges of maya species group taxa.