Plega fasciatella (Westwood, 1867)

(Figs. 4 a‒f, 5a‒c, 16c, 25, Map 1)

Mantispa (Trichoscelia) fasciatella Westwood, 1867: 503 . Holotype (or Syntypes): female, Venezuela, Santa Martha (OUM), images examined.

Plega fasciatella; Penny 1982b: 422 (cit.); Ohl 2004: 147 (cat.).

Specimens examined. Colombia: Bolivar: Mompox, 09°14’N 74°25’W, 33 m, XII.1994, (1 ♂ —MEFLG); Magdalena: Neguanje, NNP Tayrona, 11°20’N – 74°02’ W, 10 m, 21.II ~ 5.III.2001, R. Henrriquez, Malaise m‒1351 (1 ♀—ICN). Santander: Puerto Parra, Campo Capote, 06°37’08.6’’N – 73°54’30’’W, 146 m, C. Sarmiento, light trap (1 ♀—ICN).

Diagnosis. This species is distinguished by their body coloration pattern of orange and black; forewing exhibits a transverse amber stripe at midlength and at the apex, beyond of the pterostigma. Male gonocoxites have ten apical spines, subequal in length.

Redescription. Based on two females and one male, all pinned.

Head. Entirely black, mandibles dark brown (Fig. 4 d). Antenna submoniliform, with 73 flagellomeres, densely covered with thick black setae (Fig. 4 f).

Thorax. Pronotum orange, as long as mesonotum, densely covered with dark brown or orange setae; posteromedial region with a distinct bump; anterior margin medially slightly incised. Meso- and metanotum orange, mesonotum with dark brown setae; metanotum with small light brown or orange setae (Fig. 4 f). Pteropleura orange (Fig. 4 c).

Legs. Foreleg with coxa, trochanter and femur orange (Fig. 4 e). Trochanter subtriangular with dentiform process on the inner surface. Base of tibia orange, remainder black. First tarsomere amber, other with mixture of orange and black; tarsal claws amber. Mid- and hindleg with coxa, femur and 1/3 of tibia orange, remainder of tibial surface and tarsomeres black.

Wings. Forewing length 9.9‒ 13 mm; membrane orange translucent, at midlength with a broad amber transverse stripe; vention orange or brown; apex, beyond to pterostigma amber in color (Fig. 4 a). Costal field with 11‒15 crossveins; subcostal area with one crossvein at the level of Rs stem. Pterostigma orange, consisting of eigth crossveins. Three veins arising from each anterior radial cell; Rs 3‒5 gradate crossveins. Hindwing length 7.3‒ 11 mm; membrane pale orange, apical area of subcostal field and wing apex, amber. Pterostigma basally dark brown, apically orange (Fig. 4 b). Costal field with seven crossveins; three or four veins arising from 1RA cell and two from 2RA; Rs with 0‒3 gradate crossveins.

Abdomen. Abdominal segments I‒V orange. Segments VI‒IX progressively changing from brown to black. Ectoproct black, covered with long and thick setae (Fig. 4 f). Female gonocoxites black or very dark brown, arched, as long as the last four abdominal segments. Sternite VIII dark brown, with prominent dark brown or black setae.

Male genitalia. Tergite IX dark brown, except for a depigmented region laterally in the posterior half, entire surface covered with long and thick black setae. Ectoproct in lateral view elongated, elliptical, densely covered with spiniform black setae arising from protuberant bases (Figs. 5 a). Sternite VIII covered with long black setae. Sternite IX subpentagonal, posterolaterally with two pronounced lobes, posteriomedially rounded (Fig. 5 a). Pseudopenis long, forming a turn at the level of gonocoxite base, apex protruding from abdomen (Fig. 5 b). Gonocoxites cylindrical, elongated, with apex leaving from abdomen; in ventral view curved near to its midlength; ten apical spines subequal in length (Fig. 5 c).

Remarks. This species is recorded from Colombia for the first time. It is distributed in Bolívar, Magdalena and Santander (Fig. 25). Its altitudinal distribution range is between 10 and 150 m.

The type specimen of Mantispa (Trichoscelia) fasciatella shows the anal region of forewing dark amber pigmented. The specimens studied here show the same region orange and the medial transverse stripe narrower (Fig. 16 c).

Plega fasciatella has a mimetic pattern of orange and black bands, which is generally characteristics of many braconines (Braconinae) possessing abdominal glands which produce a repulsive substance in the abdomen. Interestingly, several Ichneumonidae, Tenthredinoidea ( Argidae, especially of the genus Scobina, and some Tenthredinidae), and some Chalcididae also possess this pattern. Even outside of Hymenoptera, some Reduviidae, known for their aggressive nature, are characterized by a similar colour pattern (Bolivar R. Garcete-Barret, pers. comm.).

Distribution. Colombia, Venezuela.