Dec. is, 1920 Rice Weevil, (Calandra) Sitophilus oryza 419 



clear and free and is slightly larger than the grub, so that the latter can 

 readily turn around if it desires. If it is disturbed, the grub will turn its 

 head toward the point of attack, gnashing its mandibles. 



PREPUPAL STAGE 



When it is fully grown, the larva constructs a pupal cell. It uses the 

 end of its burrow for this purpose, strengthening the weak and soft 

 sides of the cavity with a cement formed from a larval secretion mixed 

 with frass and waste material of the burrow. This forms a hardened 

 shell around the larva. After it is completed the larva becomes sluggish, 

 lengthens out, and loses its plump appearance. This prepupal stage 

 invariably lasts for one day except during the winter months when it 

 usually lasts for two days; then the pupal form is assumed. 



PUPAL STAGE 



The pupal stage normally lasts for five days. On the fourth day the 

 mouth parts begin to color, then the tips of the inner wings. Spots of 

 color show on the prothorax, the beak, and the appendages and finally 

 on all parts of the body. On the fifth day the adult form is assumed. 



DESCRIPTION OF PUPA 



Pupa uniformly pearly white when first formed. Length 3.75 to 4 mm.; width 

 about 1.75 mm. Tips of wing pads attaining seventh abdominal segment, tips of 

 metathoracic tarsi extending beyond tips of inner wings. Head rounded, beak 

 elongate and slender. Head with two prominent spines toward vertex, a group of 

 two small spines and two spinules on each side above eyes, two pairs of small spines 

 near anterior margin, and one on each side of front between the eyes. Three pairs 

 of spines on beak between frontal ones and base of antenna, a pair of small ones on 

 beak midway between base of antenna and tip of beak, a pair on sides of beak between 

 latter pair and tip of beak, and two pairs of smaller ones on tip of beak. 



Prothorax provided with one pair of anteromarginal setigerous tubercles, one pair 

 of anterolateral, two pairs of mediolateral, and four pairs of dorsal setigerous tubercles. 



Mesonotum and metanotum each provided with three pairs of spines. 



Abdomen with seven distinct dorsal tergites, the seventh being much larger than 

 the rest, dorsal area of each armed with a pair of large and a pair of smaller spines. 

 Lateral area of each tergite armed with a spine, at the base of which is a small seta. 

 Epipleural lobes each armed with two minute spines. Ninth segment as usual 

 armed with two prominent spines. 



ADULT 



The mature weevil measures from 2.1 to 2.8 mm. in length and is a 

 dull brown. It has the thorax densely pitted with round punctures, 

 and the elytra are marked with four reddish spots. 



The adult weevil on first transforming is soft and is light in color and 

 stays within the pupal cell until it has hardened and become darker. 

 It usually emerges from the grain within a few days after transforming 



