Perilypus limbatus (Gorham)

Perilypus limbatus (Gorham)

Colyphus limbatus Gorham, 1878:161 [lectotypc: male, here designated, deposited in MNHP; type-locality: Caracas, Venezuela]; 1886:336.

Derestenus limbatus var. latesuturalis Pic, 1941:11 [lectotype: female, here designated, deposited in MNHP; type-locality: Bolivia; new synonymy].

Derestenus limbatus var. notaticollis Pic, 1941:11 [lectotype: female, here designated, deposited in MNHP; type-locality: Venezuela; new synonymy].

Derestenus limbatus var. suturalis Pic, 1941:11 [lectotype: male, here designated, deposited in MNHP; type-locality: Venezuela; new synonymy].

Derestenus columbicus var. reynoldsi Wolcott, 1927b: 106 [holotype not studied; see “Remarks,” one paratype in FMNH; type-locality: El Valle, Venezuela; new synonymy].

Derestenus latefasciatus Pic, 1941:10 [lectotype: female, here designated, deposited in MNHP; type-locality: Bolivia; new synonymy].

The names in synonymy represent intrapopulation color variants.

DIAGNOSIS.—Within the limbatus group only specimens of P. limbatus, P. apocopatus, and P. decoris, have the anterior margin of antennal article 9 to 11 flavotestaceous. Perilypus limbatus differs from P. apocopatus by having the femora predominantly flavotestaceous, and from P. decoris by the narrower epipleural fold and absence of the elytral discal vitta.

DESCRIPTION.—Form: As in Figure 125.

Size: Length: males, average about 6.9 mm, range 6.3–7.6 mm; females, average about 8.2 mm, range 7.2–9.2 mm. Width: males, average about 1.9 mm, range 1.8–2.0 mm; females, average about 2.4 mm, range 2.1–2.8 mm. Ten males and 10 females measured.

Color: Clypeus, frons (Figure 57), and venter of cranium flavotestaceous; epicranium and gena shiny black; antenna predominantly black, anterior margin of articles 9 to 11 flavotestaceous, pronotum variable (see “Variation”); legs bicolorous; femur flavotestaceous, with dorsoapical infuscation diminishing from front to hind femur; tibia and tarsus black to brown; prosternum flavotestaceous, mesoand metasternum black to brown; elytron variable (see “Variation”); abdomen black.

Head: Interocular depressions shallow; frontal umbo indistinct; eyes boldly convex (HW/IOW, average about 2.2, range 2.1–2.4; 20 specimens measured); antenna (Figure 124) moderately serrate; AL/PLS, 1.7; length/width ratio of each male antennal article 2.5:1.4–1.7:1.7:2.0:1.5:1.4:1.3:1.1:1.0 1.9.

Pronotum: Only slightly transverse; PL/PW, average about 0.93, range 0.89–0.96 (20 specimens measured); subapical depression deeply impressed and strongly sinuous; pronotal arch impressed with few shallow punctations; side margin of pronotum proper moderately arcuate.

Mesoscutellum: Subquadrate.

Elytron: Epipleural margin straight in basal three-fourths, arcuate in apical fourth; apical slope gradual; disc impressed with large punctations at basal two-thirds, punctations are smaller at apical third; punctate and interpunctate surfaces smooth and shiny; epipleural fold convex; EL/EW, average about 5.1 range 4.6–5.7 (20 specimens measured).

Front Tarsal Claws: Male, strongly asymmetrical. Female, feebly asymmetrical.

Male Genitalia (Figures 128–130): Strongly pigmented. Combined length of phallobase and phallobasic apodeme 4 times longer than paramere. Combined length of paramere and phallobase 4.8 times longer than phallobasic apodeme. Paramere: Apex obtuse; lateral depression present; dorsum convex, explanate medially; venter concave; mesoventral margin straight in basal half, faintly sinuous in distal half; mesodorsal margin sinuous. Sinus: dorsal lanceolate, constricted subapically; ventral obconic. Phallus: apex papilliform; phallic plates contiguous dorsally; marginal denticles stout and extended beyond limit of phallic plicae (20 specimens examined).

Female Genitalia (Figures 131, 132): Dorsal lamina bilobed; ventral lamina trilobed, lateral lobes shorter than medial lobe; proctiger reduced; proctigeral bacculi not fused; ventral bacculus acuminate at posterior fourth; coxital plates prominent; coxital stylus bulbous distally (2 specimens examined).

Internal Reproductive Organs: Male (Figures 136, 137), anterior accessory gland uniramous, tightly coiled; posterior accessory gland biramous, outer branch about one-fourth longer than inner branch; testis composed of 12 follicles. Female, as in Figure 55; ovary composed of 12 ovarioles (5 males and 3 females examined).

VARIATION.—Structural: The degree of concavity of the elytral epipleural margin is notably variable. Females from El Valle, Venezuela, have the epipleural margin conspicuously more concave than do females from other localities; El Valle females are also more robust in body form.

Color: The available specimens, although generally homogeneous in external structure, are chromatically polymorphic. Pronotal and elytral pigmentation segregate specimens into four color phena: the bimaculate phenon (with reference to pronotal lateroapical maculae), the bivittate phenon (with reference to bivittate elytron), the punctate phenon (with reference to pronotal and apical macula), and the fasciate phenon (with reference to fasciate elytron). Both sexes are represented by the first two phena, the last two only by females.

To the bimaculate phenon I assign individuals that have a flavotestaceous lateroapical macula on each anterior angle of the pronotum (as in Figure 157) and whose elytron is vittate at the epipleural margin. In two female specimens of this phenon the pronotal disk is flavotestaceous. Specimens of the bivittate phenon have a bimaculate pronotum, and each elytron (Figure 127) has a yellow vitta on the epipleural margin and one on the sutural margin. In some specimens of the bimaculate and bivittate phena the pronotum has a fuscous testaceous macula anteriad to the fovea. In one specimen of the bivittate phenon, the marginal vitta extends only to the elytral basal half. In specimens of the punctate phenon, the pronotum is fulvous to fulvescent and has a black midapical macula and black collar (Figure 125); the pronotal macula varies in width. Members of the fasciate phenon have a punctate pronotum and a broad flavous discal fascia on the midelytron (Figure 125). The entire spectrum of color polymorphism described above is present in one population sample from Rancho Grande, Venezuela.

Seven specimens from El Limón, Venezuela, are more melanistic than the other specimens examined. They exhibit the following characteristics: posterior region of clypeus black, femur black distally, and elytral vitta absent or indistinct.

NATURAL HISTORY.—In May, in the vicinity of the Rancho Grande Biological Station in Aragua, Venezuela, I collected 53 adults, 2 larvae, and 1 pupa. The macrohabitat of the site can be described briefly as a predominantly deciduous, subtropical montane forest. The topographical location of this Andean region, generally considered a cloud forest, affords some protection from the nubilous conditions generated by the Caribbean Ocean. Consequently the collection site (at about 1100 meters) is considerably drier than adjacent mountainous areas, particularly those at higher elevations. I did not find P. limbatus specimens at 1200 meters where clouds maintained moisture level at constant saturation.

Woody lianas and low canopy verdure are two of the site’s most characteristic types of vegetation. Adults and one larva were collected by beating vegetation assemblages rich in lianas of about 7–13 cm in diameter. I found a second larva and one pupa after examining numerous sections of dead lianas that housed the immatures in a shallow cavity beneath thin bark. On the same kind of liana I observed a female oviposit into a crevice in which I subsequently found one egg. Although I failed to rear the aforementioned immatures to imago stage I am confident that they are members of P. limbatus. The pupa (Figures 380, 381) albeit not mature, clearly exhibits typical characteristics of adult Perilypus. The color markings of the pupal abdomen are identical to that found in the larvae; and I do not know of any other species of Perilypus collected from Rancho Grande vicinity. At Rancho Grande I also collected adults of this species by black light; however, the species apparently is only mildly phototropic since only three specimens were collected.

The altitudinal range of P. limbatus, as indicated by label data, is from 900 to 1500 meters.

DISTRIBUTION (Figure 362).—I studied specimens from northern Venezuela and Bolivia. The seemingly disjunct distribution is probably a consequence of coincidental collecting. The affinity of this species for subtropical montane forests suggests that they occur along the Atlantic slopes of the Andes, which would make a transamazonian distribution unlikely.

LOCALITY RECORDS (Figure 362).—I examined 122 adults, 2 larvae, and 1 pupa from South America. VENEZUELA: Distrito Federal: Caracas (ZMAN, 1 male and 1 female; FMNH, 1 male and 1 female; GEK1. 2 males; MNHP, 1 male, lectotype; NMNH, 1 male); Quebrada Avila (CBAZ, 1 male); Rio Gurimare (GEKI, 1 female): El Limón, Cordillera Del Litoral (CBAZ, 2 males and 1 female; GEKI, 2 males and 2 females); El Valle (FMNH, 2 females; GEKI, 1 female). Estado de Carabobo: Cerro de Calfe (GEKI, 1 female); Santa Clara (L’CMV, 1 male); Trincheras (GEKI, 1 female, UCMV, 1 female). Estado de Aragua: Maracay, Rancho Grande (AMNH, 2 males and 1 female; ZMAN, 3 males; BMNH, 3 males and 1 female; CBAZ, 3 males and 1 female; FMNH, 4 males; GEKI, 18 males, 19 females, 1 larva and 1 pupa; CMPP, 2 males; UCMV, 2 males and 2 females; MNHP, 2 males and 1 female; MCZC, 2 males and 1 female; MZSP, 2 males; NMNH, 13 males, 4 females and 1 larva). “Venezuela” (FMNH, 1 female, MNHP, 5 females). BOLIVIA: Departamento de Cochabamba: Cochabamba (GEKI, 1 female). “Bolivia” (GEKI, 1 male; MNHP, 3 males and 1 female).