Jan. 15, 1921 Four Rhynchophora Attacking Com in Storage 609 



EGG 



Egg opaque, shining white, bottom broadly rounded, top flattened and fitting into 

 a translucent cap. Length, without cap, 0.45 to 0.47 mm.; width 0.27 to 0.32 mm. 



LARVA 



Mature larva 2 to 2.5 mm. in length, a white, footless, fleshy grub, with body curved 

 and wrinkled. Head light brown or straw color, the anterior margin and mandibles 

 a darker brown. Head about as broad as long, almost circular in form. Epicranial 

 and frontal sutures distinct and light in color. There are also two oblique, longitudinal 

 light stripes rising from the frontal sutures and coalescing with the epicranial suture 

 near the base, of the head. Frons sub triangular, with a distinct dark median line run- 

 ning from posterior angle to middle, and indicating carina. Frons provided with 

 four pairs of large setae, sutural margins each bearing one seta. Epicranial lobes each 

 bearing the following setae: One close to posterior angle of frons and located in the 

 oblique, longitudinal stripe rising from the frontal suture, one 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 on hypostoma near base of mandible. Epistoma represented by thickened 

 anterior margin of the front. Pleurostoma represented by somewhat darker, declivous 

 area surrounding the mandibular foramen. Mandibles stout, triangular, with the apex 

 produced into an acute apical tooth. Inner edge toward apex provided with a sub- 

 apical tooth and a small medial tooth, no molar structure. Dorsal area of each mandi- 

 ble armed with a pair of stout bristles set close together. Eye represented by a well- 

 defined black spot beneath exoskeleton. Clypeus broad at base, sides narrowing 

 toward apical angles; distinctly broader but not as long as labrum. Epistomal 

 margin provided with t\vo fine hairs on each side. Labrum about as broad as long, 

 rounded in front, provided with three pairs of large setae and five pairs of short, thick- 

 ened, marginal setae. 



Maxillae terminated by a 2-jointed palpus and setose maxillary lobe. Maxillae each 

 provided with four setae as follows: One on first segment of palpus, two on vaginant 

 membrane between palpus and palpifer, and one stouter and larger one midway be- 

 tween palpus and cardo. The stipes labii enforced posteriorly by a median triangular 

 chitinization bear 2-jointed palpi and a single pair of setae. Ligula bearing four small 

 setae. Mentum and submentum fused and bearing three large setae on each side. 



Pronotum simple and undivided; praescutal and scuto-scutellar areas roughly 

 indicated by rows of setae. Mesothoracic and metathoracic segments divided above- 

 into two areas representing praescutum and scuto-scutellum ; below and adjacent to epi- 

 pleurum is the alar area. Below ventro-lateral suture are a well-defined hypopleurum, 

 coxal lobe, and eusternum. The thoracic spiracle, located on the preepipleural 

 lobe of mesothorax, is bifore, with the fingerlike air tubes pointing dorsad, and is some- 

 what larger than the abdominal spiracles. Ten abdominal segments; ninth small, 

 tenth reduced. Each tergum of first eight abdominal segments divided above into 

 three distinct areas, praescutum, scutum, and scutellum. Below and adjacent to 

 epipleurum is the alar area. Abdominal segments provided with setae as follows: 

 Two on praescutum, five on scutellum, two on alar area, two on epipleurum, one on 

 coxal lobe, and two on eusternum. Each of the first eight abdominal segments bears 

 a bifore spiracle, that of the eighth being slightly larger than the rest. 



Measurements of larval stages 



WIDTH OF 

 STAGE. LARVAL HEAD. 



1 o. 22 to o. 23 mm. 



2 • 33 to .38 mm. 



3 53 to .57 mm - 



17776°— 21 2 



