Chorosoma schillingii

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 : 376-383

Chorosoma schillingii

General nymphal description ( Figs. 14–18 , 24–33 , 42–45, 47 , 63–71 , Table 2). Body elongate, narrow, distinctly longer than wide, lateral margins subparallel ( Figs. 42, 43 ); abdominal segments 2–8 dorsoventrally, narrowly flattened laterally.

Color. General body color beige with longitudinal pink strip each side dorsolaterally from eyes to apex of abdomen; similar strip present each side ventrolaterally. Antennae generally brown. Apex of antennomere 4 and ventral surface of antennomere 1 pale; white rings on apices of antennomeres 1–3, reaching base of following antennomere in 1 st –3 rd instars; antennae entirely dark brown in 4 th and 5 th instars. Legs brownish, each apical tarsomere dark brown. Eyes red.

Head ovoid to trapezoidal, distinctly longer than wide, anteclypeus (A) longer than mandibular plates (Mp) ( Fig. 44 ). Antennae four-segmented, antennomeres cylindrically shaped, antennomere 1 short, robust; antennomeres 2–4 long, slender; antennomere 2 swollen basally; antennomere 4 slightly stouter than 3 and pointed apically in 2 nd –5 th instars ( Figs. 14–18 ). Labium four-segmented, length decreasing during development from distinctly reaching beyond hind coxae to only reaching between middle coxae.

Legs with two-segmented tarsi and two claws.

Two unpaired ostioles of DAGs on distinct medial sclerites on anterior and posterior areas of abdominal segment 5 ( Figs. 42, 43 ).

Trichobothria (T1, Ts) ventrally on abdominal segments 3–7. Spiracles (Sp) ventrolaterally on abdominal segments 2–8 ( Figs. 29–33 , 63–71 ).

Chaetotaxy. Dorsal and ventral surfaces covered with long, white setae; and long, dark brown setae, with white setae only on abdominal segments 6–9 and on antennae. Numbers of both types of setae increase during development. Specific structures such as flat setae or thorn-shaped processes in R. maculatus not found in C. schillingii nymphs.

Figures

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 24–28. Chorosoma schillingii, nymphal instars, thoracic terga (dorsal view; chaetotaxy omitted on the left side of body). (24) 1 st instar. (25) 2 nd instar. (26) 3 rd instar. (27) 4 th instar. (28) 5 th instar. Scale bars: 24–27 = 0.5 mm, 28 = 1.0 mm. Lettering: Bs, distinctly sclerotized black spot; Mg, mesonotal groove; Ms, mesonotum; Msp, mesonotal wing pads; Mt, metanotum; Mtp, metanotal wing pads; Pr, pronotum; Sc, beginning of scutellum; Sf, shallow furrow; Ss, spot with different microsculpture of cuticle; dashed line, outline of area with different microsculpture of cuticle.

FIGURES 29–33. Chorosoma schillingii, nymphal instars, (ventral view of abdomen, real chaetotaxy omitted except the right half of abdominal sterna VI–IX; right half of figure = natural left side of body with trichobothrial alveoles illustrated as open circle; left half of figure only with symbols illustrating trichobothrial pattern). (29) 1 st instar. (30) 2 nd instar. (31) 3 rd instar. (32) 4 th instar. (33) 5 th instar. Scale bars: 29–31 = 0.5 mm, 32, 33 = 1.0 mm. Lettering: III–VII, abdominal segments; Sp, spiraculum; solid circle and short seta, precursor seta; open circle and short seta, short trichobothrium; open circle and long seta, long trichobothrium.

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 63–71. Chorosoma schillingii, detail of abdominal trichobothria (ventral view; SEM, real situation, schemes on Figs 29-33). (63–66) 1 st instar. (67–71) 2 nd instar. (63, 64, 67–69) right side of abdominal venter. (65, 66, 70, 71) left side of abdominal venter. (63) sternum 3 and 4. (64, 69) sternum 5. (65, 70) sternum 6. (66, 71) sternum 7. (67) sternum 3. (68) sternum 4. Lettering: Ps, precursor seta; Tl, long trichobothrium; Ts, short trichobothrium.