Rhopalus maculatus (Fieber, 1837)

Rohanová, Markéta & Vilímová, Jitka, 2019, Nymphal development of Rhopalus maculatus and Chorosoma schillingii (Hemiptera: Heteroptera: Rhopalidae: Rhopalinae) and development of trichobothrial pattern in Rhopalidae, Zootaxa 4564 (2), pp. 367-390 : 370

Rhopalus maculatus

General nymphal description ( Figs. 1–8 , 9–13 , 19–23 , 34–41 , 46 , 48–62 , Table 2). Body weakly elongate to oval, lateral abdominal margins slightly convex.

Color. General body color green in 1 st instar, pink with red spots around bases of setae in 2 nd –5 th instars. Head, antennae, labium, thorax, and femora reddish brown. White rings on apices of antennomeres 2–3 and on bases of antennomeres 3–4, apex of antennomere 4 pale in 1 st –4 th instars, brown in 5 th instar. Reddish brown spots around bases of setae on tibiae. Eyes red. Thorax with mediolongitudinal only lightly pigmented stripe.

Head triangular in outline, anteclypeus (A) longer than mandibular plates (Mp) ( Figs. 1–3 , 34, 35 ). Antennae four-segmented with cylindrically shaped antennomeres; antennomere 1 short, robust; antennomeres 2–4 long, slender, 4 slightly swollen medially, pointed apically ( Figs. 1–3 , 9–13 ); antennomeres 2–3 roughly similar in length in 1 st instar, antennomere 2 longer than 3 in 2 nd –5 th instars ( Figs. 9–13 , Table 2).

Labium four-segmented, length decreasing during development relative to body length, reaching beyond or between hind coxae.

Legs with two-segmented tarsi and two claws ( Figs. 1–3 , 34 ).

Two unpaired ostioles (Os) of DAGs on distinct, dark, pigmented, medial sclerites between abdominal segments 4–5 and 5–6; evaporatorium compounded from medial area between ostioles and two pairs of stripeshaped areas laterally from ostioles ( Figs. 1–3 , 34, 35 , 40, 41 ).

Trichobothria ventrally on abdominal segments 3–7. Spiracles ventrolaterally on abdominal segments 2–8 ( Figs. 19–23 , 48–62 ).

Chaetotaxy. Two types of covering setae distinguishable in all instars: long, stout, erect, black setae slightly swollen apically; and short, stout, dark brown setae. Dorsal surface of head, thorax, and abdomen, and entire antennae and legs, covered with long, stout, erect, black setae. Ventral surface of abdomen with dark brown setae that are shorter than setae on dorsal surface. Setae on dorsum arranged in roughly regular rows symmetrically along longitudinal body axis ( Figs. 1–3 ). Setae on both dorsal and ventral surfaces increase in number during ontogenetic development, present in alveoles that are almost flat in 1 st instar, protuberant in 2 nd –5 th instars. General pattern of setae constant within each nymphal instar. Two other types of setae, not regularly arranged, occur in 3 rd –5 th instars: fine, short, dark brown setae located among long setae on abdominal venter; and fine, white setae of variable length, often short, on dorsal surface.

Figures

FIGURES 1–8. Rhopalus maculatus, nymphal instars (dorsal view; chaetotaxy, antennae, and legs omitted on left side of body). (1–3) Dorsal habitus: (1) 1 st instar. (2) 2 nd instar. (3) 3 rd instar. (4–8) Thoracic nota: (4) 1 st instar. (5) 2 nd instar. (6) 3 rd instar. (7) 4 th instar. (8) 5 th instar. Scale bars: 1, 2, 4, 5 = 0.5 mm; 3, 6–8 = 1.0 mm. Lettering: A, anteclypeus; Bs, distinctly sclerotized black spot; Fs, flattened seta; Mg, mesonotal groove; Mp, mandibular plate; Ms, mesonotum; Msp, mesonotal wing pads; Mt, metanotum; Mtp, metanotal wing pads; Os, ostiole/s of dorsal abdominal scent gland/s; Pr, pronotum; Sc, beginning of scutellum; Tf, transverse furrow on pronotum; Tp, thorn-shaped process; dotted line, outline of more pigmented area; black, distinctly pigmented structure.

FIGURES 9–18. Antennae of nymphal instars (dorsal view). (9–13) Rhopalus maculatus. (14–18) Chorosoma schillingii. (9, 14) 1 st instar. (10, 15) 2 nd instar. (11, 16) 3 rd instar. (12, 17) 4 th instar. (13, 18) 5 th instar. Scale bars: 9, 10, 14–17 = 0.5 mm; 11– 13, 18 = 1.0 mm. Lettering: I–IV, antennomere.

FIGURES 19–23. Rhopalus maculatus, nymphal instars (ventral view of abdomen; right half of figure = natural left side of body, with real chaetotaxy except trichobothria, only their alveoles illustrated as open circle; left half of figure only with symbols illustrating trichobothrial pattern): (19) 1 st instar. (20) 2 nd instar. (21) 3 rd instar. (22) 4 th instar. (23) 5 th instar. Scale bars: 19–21 = 0.5 mm, 22, 23 = 1.0 mm. Lettering: II–VII, abdominal segments; Fs, flattened seta; Sp, spiraculum; Tp, thorn-shaped process; solid circle and short seta, precursor seta; open circle and short seta, short trichobothrium; open circle and long seta, long trichobothrium; black, distinctly pigmented structure.

FIGURES 34–39. Rhopalus maculatus, nymphal instars (SEM): (34, 36, 37) 1 st instar. (38) 2 nd instar. (35) 3 rd instar. (39) 5 th instar. (34, 35) Total body from dorsal view. (36) Head from dorsolateral view. (37–39) The most exposed view. (37) Detail of long flattened seta laterally on abdomen. (38, 39) Detail of thorn-shaped process laterally on abdomen. Lettering: A, anteclypeus; Ds, dark seta on thorn-shaped process; Fs, flattened seta; G, groove on thorn-shaped process; Mp, mandibular plate; Ms, mesonotum; Msp mesonotal wing pad; Mt, metanotum; Os, ostiole of dorsal abdominal scent gland; Pr, pronotum; Tp, thorn-shaped process; Tpa, anterior part of thorn-shaped process; Tpp, posterior part of thorn-shaped.

FIGURES 40–44. Nymphal instars (dorsal view; SEM). (40, 41) Rhopalus maculatus, dorsum of abdomen with ostioles and evaporatorium associated with dorsal abdominal scent glands: (40) 1 st instar; (41) 3 rd instar. (42–44) Chorosoma schillingii. (42, 43) Total body from dorsal view: (42) 2 nd instar. (43) 3 rd instar. (43a) Detail of thoracic nota from Fig, 43. (44) Detail of head, 1 st instar. Lettering: III–VII, abdominal segments; A, anteclypeus; E, evaporatorium; Fs, flattened seta; M, medial sclerite; Mp, mandibular plate; Ms, mesonotum; Msp, mesonotal wing pad; Mt, metanotum; Mtp, metanotal wing pad; Os, ostiole; Pr, pronotum; Tp, thorn-shaped process; dashed line, outline of detail in Fig. 43a.

FIGURES 45–47. Detailed view of base of long trichobothrium and precursor seta in alveoles, 1 st instar (SEM): (45, 47) Chorosoma schillingii. (46) Rhopalus maculatus. (45) base and alveole of long trichobothrium. (46, 47) alveole and precursor seta. Lettering: Ps, precursor seta; Tl, long trichobothrium.

FIGURES 48–62. Rhopalus maculatus, detail of abdominal trichobothria (ventral view; SEM, real situation, schemes on Figs 19-23): (48–52) 1 st instar. (53–57) 2 nd instar. (58–62) 5 th instar. (48–53, 58–61) right side of abdominal venter. (54–57, 62) left side of abdominal venter. (48, 53, 58) sternum 3. (49, 54, 59) sternum 4. (50, 55, 60) sternum 5. (51, 56, 61) sternum 6. (52, 57, 62) sternum 7. Lettering: Ps, precursor seta; Sp, spiraculum; Tl, long trichobothrium; Ts, short trichobothrium.