Mesomphalia turrita ( Illiger, 1801 )

Simões, Marianna V. P. & Monné, Marcela L., 2014, Description of immatures of Mesomphalia gibbosa (Fabricius, 1781) and Mesomphalia turrita (Illiger, 1801) (Coleoptera: Chrysomelidae: Cassidinae: Mesomphaliini), Zootaxa 3861 (5), pp. 466-478 : 470-476

Mesomphalia turrita ( Illiger, 1801)

( Figs 8–39 )

Biology ( Figs. 8–11 ). Two females each oviposited nine eggs, which were kept in the laboratory to obtain firstinstar larvae. The adults did not demonstrate parental care. Two oviposition patterns were observed. The first was observed in the laboratory, where the eggs were laid directly on the surface of the leaf with only the first egg attached to a filamentous stalk (= remainder, Świętojańska 2009) and positioned separately in two groups of five and three eggs. The second oviposition pattern was observed in the field. The eggs were laid on the bottom of a leaf, with all nine eggs together and attached to a filamentous stalk in a crescent shape. First-instar larvae showed gregarious behaviour ( Figs. 8–11 ) and fecal material was piled on the supra-anal processes, with the next two instars retaining the exuviae of the previous instars.

Eggs ( Figs. 12–14 ). Measurements (n = 9). Length: 2.5–2.8; width: 1.1–1.2. Eggs ( Fig. 12 ) are elongate-oval, brown, with a dark-brown elevated and tapered micropylar area. The surface of the chorion ( Figs. 13–14 ) is irregular, with sparse depressions and short, uneven longitudinal ridges of wax secreted by the female during oviposition.

First-instar larva ( Figs. 15–38 ). Measurements (n = 6). Length without head, from anterior border of pronotum to base of supra-anal processes: 3.1–4.0; width of mesonotum excluding lateral scoli: 0.8–1.0.

Body ( Fig. 15 ) flattened dorso-ventrally, oval, dorsal side with microtrichia, moderately narrowed posteriorly, widest across meso- and metathorax. Fourteen pairs of lateral scoli ( Figs. 33–34 ) and pair of supra-anal processes ( Figs. 37–38 ). Scoli of pairs IV, VII–XI shortest and XII–XIV longest; supra-anal processes ( Figs. 37–38 ) about 1.4 times longer than longest lateral scoli. Lateral scoli unbranched ( Fig. 33 ), covered with numerous long pointed setae, apex ( Fig. 34 ) with one long pointed seta. Each supra-anal process covered with numerous long pointed setae, apically unarmed ( Fig. 37 ) or with two pointed setae ( Fig. 38 ).

Color: Integument of ethanol-preserved larva yellow with dark-brown head, pronotum, lateral scoli, supra-anal process, abdominal tergites X–XI, legs, round spots on meso-, metanotum and abdominal tergites.

Head ( Figs. 16–17 , 20 ) well sclerotized, hypognathous, retracted into prothorax, frons with slight transverse depression under Fb rows of setae. Endocarina complete, connected with fronto-clypeal suture. Antennae ( Figs. 18–19 ) short, two-segmented, set in membranous ring. First segment short, ring-like and transverse; second stout, as wide as long, with one seta at base and group of four peg-like sensilla at apex and one conical minute process (sensory appendix). Frontal side of head with four small, vertically directed, pointed setae (V 1–4), and five frontal rows of setae: row Fa with 3 setae, Fb with eight to ten setae, Fc with three setae, Fd with one seta, Fe with two setae. Tempora with three setae (T 1–3) slightly shorter and thinner than setae of frons. Six paired prominent stemmata laterally ( Fig. 17 ). Fronto-clypeal suture present. Clypeus distinct, wider than long with three setae, two positioned on right side and one on left side. Labrum ( Figs. 21–22 ) two times wider than long; anterior margin with eight short stout setae medially ( Fig. 22 ); seven long pointed setae on each side, all visible in dorsal as well as ventral views. Dorsal side of labrum ( Fig. 21 ) with four long setae and two short setae near anterior margin. Mandibles heavily sclerotized, curved and stout, with four distinct triangular teeth in one row. Dorsal side of mandibles ( Fig. 23 ) at apex and near base with two long setae each. Maxillae and labium ( Fig. 24 ) connate. Each stipes with three pointed setae. Mala and lacinia ( Fig. 25 ) not distinct from palpiger. Palpiger with two long ventral setae. Lacinia protuberant, covered with numerous spines placed dorsally on palpiger. Maxillary palpus ( Fig. 25 ) two-segmented: first segment with two short setae; second segment with group of sensilla apically, and one seta subapically. Labial palpi ( Figs. 26–27 ) one-segmented, with apical group of sensilla. Prementum ( Fig. 24 ) trapezoidal with two short setae. Postmentum with six setae.

Spiracles of thorax and abdominal ( Figs. 35–36 ) segments I–VII distinctly elevated and their diameter very slightly decreasing posterad. Spiracles of abdominal segment VIII extremely small. Abdomen 11-segmented, with one long seta on each side close to spiracle, and two transverse rows of setae dorsally. Tergite I with six protuberances anteriorly, each armed with one long seta; four protuberances posteriorly, armed with five setae, disposed as 1, 1, 2 and 1; anterior and posterior rows of tergites II–VIII with four protuberances, each armed with one long seta. Abdominal sternites I–IV with 16 setae: six medially on each segment and five laterally; V–VII with 14 setae: six medially on each segment and three long and one short setae laterally; VIII with two short setae medially.

Legs ( Figs. 30–31 ) three-segmented, short, stout and covered with numerous setae. Tibiotarsus wellsclerotized apically, with single simple claw ( Figs. 30–31 ) armed basally and dorsally with pointed setae; claw and pointed setae surrounded by spatulate setae ( Fig. 32 ); ventral setae on tibiotarsus distinctly spatulate, shorter than on dorsal side.

Pupa ( Fig. 39 ). Measurements (n=2). Length of body: 12.0–12.4; width across second abdominal segment, without lateral scoli: 8.0. Length of pronotum: 3.0; width of pronotum: 9.2–9.5.

Body (Fig. 45) oval. Pronotum yellow, with posterior margin and exuvial line brown. Meso- and metanotum yellow with median longitudinal brown stripe. First abdominal tergite brown with posterior third yellow; and median longitudinal brown line. Abdominal tergites II–IX yellow, with lateral end and exuvial line on tergites II–V (or VI) brown. Lateral scoli smooth, I–V brown, VI–VII whitish yellow. Sternites yellow. Antenna, mouth parts, prosternum and legs brown. Elytral portions brownish yellow.

Pro-, meso- and metanotum without processes or lateral scoli. Abdominal tergites and sternites with setae distributed regularly on entire surface; segments I–II with lateral scoli tapered toward their apices; III–V with lateral scoli truncate at base and conical at apex, pointing outward; VI folded laterally; VI and VII–VIII pointing downward. Size of scoli decreasing posterad.

Abdominal segments I–VI with pair of spiracles; diameter of each pair of spiracles decreasing posterad.

Exuvium of last instar remained attached to the pupa on sternum VIII.

Figures

FIGURES 8 – 13. Mesomphalia turrita (Illiger, 1801). Egg and first-instar larva. 8 – 11, larvae showing gregarious habit; 12 – 13, eggs: 12, egg remnants; 13, surface with sparse depressions.

FIGURES 14 – 19. Mesomphalia turrita (Illiger, 1801). Egg and first-instar larva. 14, egg surface with wax and newly hatched first-instar larva; 15 – 19, first-instar larva: 15, general aspect of larvae; 16 – 17, head: 16, dorsal view; 17, lateral view; 18 – 19, antenna, with numbers indicating the peg-like sensilla: 18, frontal view; 19, lateral view (Fa, frontal row of setae; sa, sensory appendix; V 1 – 4, vertically directed setae).

FIGURES 20 – 27. Mesomphalia turrita (Illiger, 1801). First-instar larva. 20, mouth parts, general aspect; 21 – 22, labrum: 21, general aspect; 22, emargination of anterior margin of labrum; 23, part of mandible and anterior margin of labrum laterally; 24, maxillae and labium, general aspect; 25, maxillary palp, labial palp and palpiger; 26 – 27, labium and premantum: 26, general aspect; 27, labial palp (lp, labial palp; mal, mala; mpI, maxillary palp I; mpII, maxillary palp II; post, postmentum; pp, palpiger; pre, prementum; st, stipes).

FIGURES 28 – 32. Mesomphalia turrita (Illiger, 1801). First-instar larva. 28 – 29, setae on anterior margin of pronotum: 28, long seta; 29, minute seta; 30 – 32, proleg: 30, proleg, general aspect; 31, single simple claw at apex of tibiotarsus; 32, greater detail of spatulate setae surrounding claw.

FIGURES 33 – 39. Mesomphalia turrita (Illiger, 1801). First-instar larva. 33 – 34, lateral scoli: 33, general aspect; 34, apex; 35 – 36, spiracle: 35, general aspect; 36, detailed external opening; 37 – 38, supra-anal process: 37, unarmed; 38, armed with two acute setae; 39, pupa, dorsal.