Clytrini

Agrain, Federico A. & Marvaldi, Adriana E., 2009, Morphology of the first instar larva in the tribe Clytrini, with two new descriptions in the subtribe Megalostomina (Coleoptera: Chrysomelidae: Cryptocephalinae), Zootaxa 2147, pp. 59-68 : 61-62

Tribe Clytrini Lacordaire

The following tribal description is based on the first instar larvae of two species in the genera Megalostomis and Coscinoptera described herein, and on published information of ten species in six genera: Lachnaia ( Fiori 1948) , Smaragdina ( Medvedev 1962) , Clytra ( Lee & Morimoto 1991a), Anomoea ( LeSage & Stiefel 1996) , Coptocephala ( Pietrykowska 2000) , and Labidostomis ( Wąsowska 2007) .

General body aspect (see Figs. 3, 8 ). Body J-shaped; head hypognathous, legs long and well developed.

Head (see Figs. 11–17 , 21–27 ). Fully exposed, subcircular, well sclerotized, surface of frons and epicranial halves with tuberculate sculpture pattern. Epicranial line (coronal suture) well developed, about 1/3 the length of head, frontal lines broadly divergent and weakly bisinuate. Endocarina absent. Stemmata well developed, 6 in number, in two groups: 4 behind antenna and visible in dorsal view, and 2 below antenna and visible in ventral view. Antennae mounted on ventral surface and partially hidden in dorsal view by frontal projection, 2-segmented, basal segment with 2 sensilla, apical segment with several sensilla and minute setae plus one long seta close to the sensorium, the latter dome-like. Epicranium with 4 minute posterior epicranial setae accompanied by 1 sensillum; 5 dorsal epicranial setae, spatulate and papillate, with 3 dorsal sensilla; 3 lateral epicranial seta and 3 stemmatal setae; frons usually with 6 spatulate and papillate setae (more than 6 setae, 13-14, in Megalostomis lacordairei and Coptocephala rubicunda (Laicharting)) . Frons, clypeus and labrum fused, without distinct frontoclypeal or clypeolabral sutures. Clypeus-labrum transverse, on each side with 4-5 setae and 2 sensilla: 1 seta and sensillum apparently of clypeus and 3-4 labral setae, 1 on disc and near labral sensillum and 2-3 along antero-lateral margin. Labrum incised on anterior margin, usually sinuate. Epipharynx with 5-7 pairs of setae on anterior margin. Head in ventral view, with tentorial bridge narrow, with a pair of anterior tentorial arms. Mandibles robust, symmetrical, 4-toothed: two apical teeth and 2 blunt projections on incisor section; without mola, penicillus and retinaculum; 2 mandibular setae, longitudinally placed on outer margin, 2 sensilla, one near base of innermost tooth and the other between setae. Maxilla: cardo with 1 seta; stipes more than 2 X longer than wide, with 2 large setae and 1 sensillum on outer margin and 1 minute inner apical seta; palpiger sclerotized and with 2 setae and 1 sensillum; maxillary palp 3- segmented, basal segment with 2 sensilla, middle segment with 2 setae and 1 sensillum, apical segment with 1 seta and 1 sensillum plus elongate “accessory process”; lacinia fused with stipes, forming inconspicuous lobe at base of galea, bearing 2 stout setae on inner side; galea with 5 ventral setae and 1 sensillum, and a row of 4- 5 dorsal setae plus 2 other setae at base. Labium with prementum and postmentum not fused. Postmentum connected ventrally with thoracic sternum and laterally directly with maxillae, without articulatory area or lobe; 3 postmental setae (pms), basal pair (pms1) distantly separated from pms2 and pms3, 1 sensillum between pms2 and pms3; prementum with 1 minute seta (at base) and 1 long seta and 1 sensillum; ligula membranous, with 3 setae and 2 sensilla; labial palp 2-segmented, basal segment with 1 sensillum, apical segment with 1 sensillum and sensory papilla at apex.

Thorax ( Figs. 18–20 , 28–30 ). Pronotum sclerotized, pigmented (brown), pale median line separating both halves, each with 14 pronotal setae and 7 sensillae (5 of these on anterior margin). Meso- and metathorax pigmented laterally, only weakly sclerotized. Egg bursters present on meso- and metathorax, on weakly sclerotized dorso-lateral postero-interior (DLpi) tubercles, each consisting of a small subtriangular “spine” situated anterior to base of very long seta and near short seta ventral to these. Meso-thoracic spiracle, uniforous, peritreme broad and reticulate, subcircular to oval. Legs, well developed, similar sized, similar shaped, and sclerotized; with coxa, trochanter, femur, tibiae and tarsungulus; first four bearing setae and sensilla, the tarsungulus slightly curved (claw like), with 1 seta at base.

Abdomen ( Figs. 3, 8 , 18 , 28 ). Abdominal segments not sclerotized, widest at middle part (abdominal segments V and VI), distal end (segments V- X) bent downwards and recurved ventrally (body J-shaped). Spiracles on abdominal segments I to VIII, lateral, similar to thoracic spiracle, with reticulate peritreme, but smaller.

(6–10) Coscinoptera argentina Burmeister , 6. Adult female, habitus, anterolateral; 7 – 10. First instar larva, 7. Head capsule, one half dorsal, showing cuticle sculpture pattern of frons and epicranium; 8. Habitus, lateral; 9. Detail of thoracic spiracle; 10. Larva in its case.

Figures

FIGURES 1 – 10. (1 – 5) Megalostomis (H.) lacordairei Lacordaire. 1. Adult female habitus, anterolateral; 2 – 5. First instar larva, 2. Head capsule, one half dorsal, showing cuticle sculpture pattern of frons and epicranium; 3. habitus, lateral; 4. Detail of thoracic spiracle; 5. Larva in its case.

FIGURES 11 – 20. Megalostomis (H.) lacordairei, first instar larva. 11, 12. Head, dorsal and ventral; 13. Detail of (left) antenna; 14. Clypeus-labrum; 15. Epipharynx; 16. Mandible; 17. Maxilla and labium (a, ventral; b, dorsal maxilla); 18. Thorax and 1 st abdominal segment, dorsolateral (one side); 19. Detail of tubercle bearing egg burster and setae; 20. Pro- leg, lateral. Scales = 0.1 mm.

FIGURES 21 – 30. Coscinoptera argentina, first instar larva. 21, 22. Head, dorsal and ventral; 23. Detail of (left) antenna; 24. Clypeus-labrum; 25. Epipharynx; 26. Mandible; 27. Maxilla and labium (a, ventral; b, dorsal maxilla); 28. Thorax and 1 st abdominal segment, dorsolateral (one side); 29. Detail of tubercle bearing egg burster and setae; 30. Proleg, lateral. Scales = 0.1 mm.