Description subantarcticus
Creators: name: Pereyra, Hugo A.
name: Pancotto, Verónica A.
name: Coscarón, M. Del Carmen
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Aenictopecheidae
Description

description: Description of immature stages
Fifth Instar (Figs. 2A, B)
As described by Wygodzinsky & Schmidt (1991) the fifth instar nymph: “general shape is stout. Eyes well developed. Antennae slender. Neck not distinct. Wing pads not meeting medially, longer than wide, rounded posteriorly. Abdomen membranous; terga III–VII with ordinary setae and with macrochaetae (1+1 submedian, 1+1 sublateral and 1+1 lateral)”.
Male: Length 4.68–4.73 mm; average width 0.93–0.99 mm; head length 0.72–0.73 mm and width 0.50–0.51 mm; interocular distance 0.30–0.31 mm; pronotum length 0.59–0.78 mm and width 0.91–0.95 mm; forewing pads length 1.26–1.27 mm and width 0.35–0.43 mm; hindwing pads length 1.09–1.12 mm and width 0.35–0.39 mm; additional body measurements are provided in Table 1.
Female: Length 5.90–7.01 mm; average width 1.17–1.57 mm; head length 0.76–0.82 mm and width 0.47– 0.57 mm; interocular distance 0.31–0.36 mm; pronotum length 0.58–0.85 mm and width 0.94–1.01 mm; forewing pads length 1.04–1.36 and width 0.42–0.48 mm; hindwing pads length 1.01–1.11 mm and width 0.33–0.34 mm; additional parameters are presented in Table 1.
Colouration.Body reddish to orange,differing from adults which are dark to black.Eyes bright red,intersegmental junctions throughout body lighter colour, red in region of ecdysial suture. Anterior and posterior lobes of head dark brown, distally tinged with red dorsally except basal edge of eyes, light brown tinged with orange ventrally, labial segments brown; antennae brown; pronotum, mesonotum and metanotum dorsally light brown tinged with red, ventrally lighter brown than dorsally; wing-pads dark to light brown; abdomen in dorsal view red tinged with orange, ventral view light red tinged white orange except alternated creamy areas, distal area brown as in Figure 2A, B. Mid and hindlegs pale yellow to yellowish, slightly darker in middle part of femur and basal part of tibia. Hind coxa and trochanter brown except intersegmental line and surrounding areas. In dorsal view more than half of femur whitish, in ventral view most of femur brown, in both views with well-defined colour pattern. Tibia darker basally, brown dorsally and lighter ventrally, colour boundary not defined; bristles yellowish.
General morphology similar to that of adult, head, abdomen and appendages polished, body and appendages covered with numerous long and delicate bristles, shorter ones also present on forewing pads.
Head longer than pronotum, eyes large, in lateral view almost attaining dorsal and ventral outline of head.Antennae pilose, as long as head and pronotum together; first segment shortest, third segment longest, proportions 1:1.9:2.0: 2.2 in male, 1:2.1:2.4: 2.3 in female, apical segment slightly spindle-shaped. Rostral segments conical, basal segment shorter, third segment longer than other segments, proportions 1:1.35:2.55: 1.68 in male, 1:1.41:2.29: 1.37 in female.
Pronotum trapezoidal, disk rather flattened, anterior margin straight to slightly concave, posterior margin straight. Length to width 1: 1.5 in male, 1: 1.6 in female.
Mesonotum without distinct lobes, slightly flattened dorsally, lateral margins rounded, anterior margin straight to slightly concave, posterior margin slightly rounded. Length to width 1: 1.5 in male, 1: 1.8 in female. Forewing pads membranous inserted anteriorly, wings base half wide of mesonotum, longer than broad, posteriorly rounded, reduced venation, marked depression on middle-lateral costal margin (wing costal fracture in adults). Forewing pads length to width 1: 0.3 in male, 1: 0.4 in female.
Metanotum lateral margins rounded, anterior margin slightly concave, posterior margin U-shaped. Length to width 1: 2 in male, 1: 1.8 in female. Hindwing pads membranous, posteriorly rounded, medially spaced, inserted anteriorly, wing base wider than half of metanotum, extended 0.2 mm respect forewing pads, smaller than forewing pads. Length to wide 1:0.3 both male and female.
Forelegs similar to adult, length to width 1:0.4 femur, and 1:0.4 tibia in male; 1:0.5 femur and 1:0.4 tibia in female. Tarsal and tibial spines similar to adult; mid and hindlegs slender. Hindlegs length to width 1:0.19 femur and 1:0.14 tibia in male, 1:0.14 femur and 1:0.17 tibia in female.
Genitalia development in female and male evident.
Material examined: 2 males, 2 females.
Fourth Instar (Figs. 2C, 3)
Male: Length 3.67–3.91 mm; average width 0.81–0.89 mm; head length 0.67–0.70 mm and width 0.43–0.46 mm; interocular distance 0.28–0.32 mm; pronotum length 0.39–0.56 mm and width 0.77–0.84 mm; forewing pads length 0.47–0.57 mm and width 0.20–0.22 mm; hindwing pads length 0.44–0.45 mm and width 0.15–0.21 mm; additional body measurements are provided in Table 1.
Female: Length 4.49–4.53 mm; average width 0.98–1.31 mm; head length 0.68–0.69 mm and width 0.44–0.49 mm; interocular distance 0.28–0.32 mm; pronotum length 0.57–0.61 mm and width 0.87–0.88 mm; forewing pads length 0.63–0.68 mm width 0.25–0.27 mm; hindwing pads length 0.49–0.51 mm width 0.21–0.26 mm; additional body measurements are provided in Table 1.
Morphology similar to fifth instar, except in the following characters. Head, thorax and forelegs lighter. Third and fourth antennal segments are subequal. Rostral segments, proportions 1:1.20:2.30: 2.25 in male, 1:1.10:2.20: 1.51 in female.
Mesonotum and metanotum wider than long, ratio 1:2.0 and 1: 2.3 in male, 1:2.2 and 1: 1.5 in female, respectively. Forewing pads oval-shaped membranous inserted anteriorly and overlapped less than half of wide mesonotum and metanotum, approximately half length of 5th instar. Forewing pads with a slight depression on the inner side margin of the forewing pads. Hindwing pads extended 0.3 mm respect forewing pads.
Genitalia development as seen in Fig. 3.
Material examined: 3 males, 2 females.
Third Instar (Fig. 2D)
Length 2.92–2.94 mm; average width 0.60–0.61 mm; head length 0.51–0.52 mm and width 0.34–0.35 mm; interocular distance 0.22–0.23 mm; pronotum length 0.439–0.47 mm and width 0.50–0.62 mm; additional body measurements are provided in Table 1.
Similar to fourth instar, differing in the following characters. Colour of thorax and abdomen similar, dark orange on the edges. Head and forelegs lighter than 4th instar. Antennal segments of diferents size, rostral segments, proportions 1:1.3:2.0:1.5.
Pronotum subquadrangular, with anterior edges shallowly concave, posterior edges rounded. Mesonotum and metanotum subtrapezoidal, length-width 1:14, 1:1.8 and 1:2.7. with globose posterior margins. Wing pads absent.
Material examined: 2 specimens.
Second Instar (Fig. 2E)
Length 2.30–2.83 mm; average width 2.56–2.71 mm; head length 0.33–0.45 mm and width 0.26–0.35 mm; interocular distance 0.17–0.25 mm; pronotum length 0.32–0.42 mm and width 0.42–0.58 mm; additional body measurements are provided in Table 1.
Similar to third instar, differing in the following characters. Head and forelegs lighter, rostral segments, ratio 1:1.11:2.10:1.50. Pronotum, mesonotum and metanotum length to width 1:1.3, 1:3 and 1:2.4. posterior margins globose.
Material examined: 12 specimens.
First Instar (Fig. 2F)
Length 1.82–1.83 mm; average width 0.52–0.53 mm; head length 0.26–0.30 mm and width 0.23–0.27 mm; interocular distance 0.14–0.19 mm; pronotum length 0.21–0.29 mm and width 0.35–0.44 mm; additional body measurements are provided in Table 1.
Similar to second instar, differing in the following characters. Colour of head and first pair of forelegs similar to thorax and abdomen. Fourth antennal segment longer, second and third subequal. Third and fourth rostral segments subequal, proportions 1:1.2:1.7:1.9.
Mesonotum and metanotum, length to width 3:2 and 1:2.08, posterior margins globose.
Material examined: 2 specimens.
description: Published as part of Pereyra, Hugo A., Pancotto, Verónica A. & Coscarón, M. Del Carmen, 2023, Description of immature stages of Gamostolus subantarcticus (Hemiptera: Heteroptera: Aenictopecheidae) from Tierra del Fuego, Argentina, pp. 177-184 in Zootaxa 5339 (2) on pages 179-181, DOI: 10.11646/zootaxa.5339.2.4, http://zenodo.org/record/8297263