Megalostomis (Heterostomis) lacordairei Lacordaire

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 : 62-65

Megalostomis (Heterostomis) lacordairei Lacordaire

( Figs. 1–5 , 11–20 ).

First instar larva (characters defining the tribe are not repeated here) ( Figs. 2–5 , 11–20 ).

Maximum dimensions: Body length 3.46 mm; head width 0.63 mm. Body of typical shape; coloration pale yellow when alive (body coloration turning white after preservation in ethanol). Head with a characteristic sculpture pattern, of round tubercles grouped in stripes between setae, on frons and epicranial halves ( Fig. 2 ). Frons with 13 setae, spatulate papillate in shape. Labrum incised on anterior margin, without distinct lobes. Epipharyngeal sensilla in clusters of 3 (anterior) and 2 (posterior). Maxillary galea with row of 5 dorsal setae plus 2 setae at base.

Egg and first larval case ( Fig. 5 ) ovoid, yellow, without fecal plates, covered with a bright, transparent, secretion.

Material examined. Three first instar larvae (two slide-mounted) from eggs deposited by adults collected in ARGENTINA : Catamarca Province, between Esquiú and Ramblones (Lat. - 29.288054; Long. - 65.367721), 3 March 2006, feeding on leaves of Prosopis sp., F. A. Agrain, S. Roig and T. Erwin coll. (IADIZA). A total of 34 adults (both sexes) were collected by hand, from host plant foliage; some females laid eggs, together producing seven eggs soon after capture, and although eggs were later contaminated by fungi, three first instar larvae successfully hatched after six days.

Remarks. The lack of egg fecal coating by the female of Megalostomis (Heterostomis) lacordairei cannot be due to inadequate nourishment, as has been suggested for Clytra quadripunctata by Rosenbauer 1852, since oviposition occurred within a few minutes after females were captured, and thus they were naturally fed (there were abundant fresh leaves available in the collecting site, and plant material was found in the digestive system of dissected females).

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.