Dec. is, 1920 Rice Weevil, (Calandra) Sitophilus oryza 417 



DESCRIPTION OF LARVA 



Mature larva from 2.5 to 3 mm. in length. A pearly white, fleshy grub, very thick- 

 bodied, the ventral outline being approximately straight while the dorsal outline is 

 almost semicircular. Head light brown in color, the anterior margin and mandibles 

 much darker. Head longer than broad and somewhat wedge-shaped, the sides 

 broadly rounded from middle to apex, which is slightly angular. Sides nearly straight 

 from middle to the anterior angles, and lateral area with an oblique, longitudinal, 

 lighter stripe or area. Epicranial and frontal sutures distinct and light in color; also 

 two oblique, longitudinal, light stripes rising from frontal sutures and coalescing with 

 epicranial suture near base of head. Frons subtriangular with a distinct, dark, 

 median line indicating the carina running from the posterior angle to beyond the 

 middle. Sutural margins irregular or sinuate. Frons provided with five pairs of 

 large setse, the sutural margins each bearing a large seta. Each epicranial lobe bearing 

 the following sets: One close to posterior angle of frons and located within the oblique, 

 longitudinal stripe rising from the frontal suture; one very small seta posterior to this 

 and near occiput; two anterior to it on disk of epicranium; two opposite middle of 

 frons; one opposite middle of mandible; one opposite hypostomal angle of mandible; 

 and one 011 hypostoma near base of mandible. Epistoma represented by thickened 

 anterior margin of front, distinctly darker in color, with anterior margin declivous and 

 slightly curving and lateral angles slightly produced and elevated where they sup- 

 port the dorsal articulation of the mandibles. Pleurostoma represented by the darker 

 declivous area surrounding the mandibular foramen. Mandibles stout, triangular, 

 with the apex produced into a broad apical tooth; inner edge toward the apex pro- 

 vided with a subapical tooth and a small medial tooth; no molar part. Dorsal 

 area of mandible provided with a pair of stout bristles set apart. Eye represented 

 by a well-defined black spot beneath the exoskeleton. Clypeus attached in front of 

 frons and broadly transverse, broad at base, sides narrowing toward the apical angles, 

 slightly longer and broader than labrum, and bearing on epistomal margin two fine 

 setse on each side. Labrum distinctly broader than long, with two small lateral and 

 a larger, rounded, median lobe. Labrum provided with six large setse behind mid- 

 dle, two marginal, short, thickened setae on each lateral lobe, and six similar marginal 

 setae on median lobe. 



Maxilla with cardo present and distinct, stipes not divided into stipes proper, sub- 

 galea, and palpifer but one continuous piece, with the anterior inner angle produced 

 into a single setose lobe. Palpus 2-jointed, bearing a single seta near apex of first 

 segment. There are three other setae on maxilla, two located on the vaginant 

 membrane between palpus and palpifer and one stouter and longer midway between 

 palpus and cardo. No articulating maxillary area between maxilla and mentum- 

 submental region. 



Labium: Submentum and mentum fused and represented by a broad lobe bearing 

 three pairs of stout setae. Stipes labii posteriorly enforced by a median, triangular 

 chitinization, the anterior, median section produced anteriorly between the palpi 

 into a small lobelike ligula which is fused with the lingua. Each stipes labii bearing 

 a single seta. The short, conical, 2-jointed palpi are situated on the anterior angles 

 of the stipites. The ligula bears four small setae. 



Prothorax dorsally not divided, but two areas, praescutal and scuto-scutellar, are 

 roughly indicated by rows of setae. The mesothoracic and metathoracic segments 

 are above divided into two distinct areas, the anterior of which represents the prae- 

 scutum and the posterior the scuto-scutellum and alar area. The thoracic spiracle 

 is located on a lobe pushed into the prothorax from the epipleurum of the mesothorax. 

 It is bifore, elongate, larger than abdominal spiracles, and placed with the fingerlike 

 air tubes pointing dorsad. 



