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Prionus coriarius
Classification
Diagnostic Features of Larvae
- Mature larva. Length up to 76 mm; breadth (at prothorax) 14.25 mm. Form subcylindrical, very robust, gradually tapering posteriorly to ninth segment. Head moderately depressed, slightly transverse (maximum head-width 9.2 mm). Genae very strongly shouldered, rugose, darkly pigmented and bearing a few pale setae. Mouthframe strongly sclerotized, rugose, broadly pitchy. Frons with a broad pitchy anterior margin which merges posteriorly into a ferruginous area, which in tum gradually merges into a smooth testaceous area. Front margin of frons comprising a pitchy, heavily sclerotized ridge, which is abruptly sloping; upper boundary varying from straight to slightly bilobed, keel-shaped and notched medially; lower boundary produced over clypeus in four rugose lobes, the paramedian pair being small and blunt. Postcondylar carina distinct. Subfossal process acutely conical. Antenna three-segmented; second segment barrel-shaped, obliquely truncate apically, and bearing a minute oval sensory organ and a dome-shaped apical segment. Mandible very robust, pitchy, shining, with outer face strongly rugose. Labrum transversely oval, leathery, and with numerous stout setae. Ocelli absent. Gula extremely short; sutures diverging to meet anterior portion of occipital foramen. Prothorax moderately depressed, about twice as broad as long, with a conspicuous transverse ferruginous band near front margin. Pronotum rectangular, delimited laterally by a pair of conspicuous grooves; median cleavage line shallow, distinct; anterior region transversely rugose, bearing a few scattered setae; posterior region irregularly rugose, glabrous. Eusternum distinctly separated from presternum by a V-shaped suture. Sternum coarsely rugose, with a few scattered short setae. Mesonotum and metanotum irregularly rugose, almost glabrous. Abdomen with dorsal and ventral ampullae on segments one to seven. Pleural discs present on segments one to six; each radially striate, with a deep pore. Segments eight and nine feebly rugose, the latter large, extended, and with a few short, pale setae. Tenth segment trilobed, each lobe strongly protuberant, rugose and bearing a few fine setae. Legs rather short (slightly longer than maxillary palpi), ferruginous, very setose. Spiracles of mesothorax broadly oval; metathoracic pair minute; abdominal spiracles with peritreme broadly oval, thick, and slightly raised above general level of cuticle.
Pupa. Length 29-40 mm; maximum breadth 15 mm. Head almost concealed from above by prothorax; glabrous, with four converging series of striae on disc. Antennae thick (serrate in male), extending as far as first abdominal segment. Labrum triangular, elongate, glabrous. Pronotum strongly transverse, with three pairs of lateral tubercles, the middle pair being the most strongly produced; transversely striate, glabrous. Mesonotum similarly striate, glabrous; scutellum prominent, fleshy, glabrous. Metanotum almost smooth. Elytra and wings extending as far as fourth abdominal segment. Abdomen with tergites rugose, the first six bearing scattered minute papillae; sternites smooth (except last two), and glabrous; ninth tergum markedly rugose, with two paramedian, elongate, fleshy protuberances. Legs with hind femora extending only as far as third abdominal segment. Functional spiracles present on first six abdominal segments, the seventh pair being almost closed and probably non-functional; peritreme narrowly oval and rather thick.
Egg. Form elongate-ovoid, with rounded ends, the posterior pole being slightly attenuated. When first deposited, the egg is almost white, becoming light brown later, and, if the secretion has been applied thickly, slightly shining as though varnished; but often the secretion fails to cover the egg completely and leaves dull patches. The average dimensions of twelve eggs were 4.1 mm long by 1.4 mm at their greatest width. The chorion is opaque, exceedingly thick and coarsely reticulated, each polygonal area being depressed and having a minute though deep puncture in the middle. Adapted from Duffy (1953).
Biology and Economic Importance
- Biology and economic importance for this taxon coming soon.
Selected References to Larvae Specimens
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