328 ECONOMIC ENTOMOLOGY 



punctured; wing-covers ridged lengthwise; April- June. One genera- 

 tion each year; nocturnal. 



^iS^- — White, bean-shaped, ^q inch long; deposited in the meal. 



Larva. — Cylindrical, waxy and slender; i inch long, resembling 

 wireworms; yellowish, darker at each end. Mature in 3 months. 



Pupa. — Duration about 2 weeks. 



The Dark Meal-woim (Tenebrio ohscurus Fab.) is dull pitchy 

 black and has similar habits to the preceding. 



Control. — Subject infested rooms to a temperature of i2o°-i25°F. 

 for 6 hours; fumigate with hydrocyanic acid gas or carbon bisulphide. 



Confused Flour Beetle {TrihoUum confusum Duval). Adult. — A 

 small, shining, reddish-brown beetle, % inch long; flattened, oval; 

 head and thorax finely punctate; wing-covers ridged lengthwise 

 and sparsely punctate. 



Eggs. — Minute, white, hatching in 6 days. 



Larva. — Cylindrical, wiry, yellowish-white, l<, inch long; mature 

 in 24 days. 



Pupa. — White, matures in 6 days. 



CURCULIONID^ (WEEVILS) 



Common Economic Genera: 



A. Claws simple, pygidium not exposed. 



B. Antennas straight, club annulated, claws toothed, gular peduncle 

 broad. — Ithycerus. 

 BB. Antennas elbowed, rostrum with distinct scrobes, gular peduncle long; 

 front coxae contiguous. 



C. Mandibles usually emarginate, 2-toothed at tip. — Phytonomus. 

 CC. Mandibles bi-emarginate, 3-toothed at tip. 



D. Lateral angles of first ventral segment uncovered. — Lixus. 

 DD. Lateral angles of first ventral segment not visible. — Fissodes. 

 A A. Claws appendiculate, toothed or cleft (except in Tylodenna). 



B. Ventral sutures straight, hind angles of prothorax rectangular or 

 rounded, prosternum short, broadly emarginate; eyes rounded, 

 distant. — Anthonomiis. 

 BB. Ventral sutures more or less curved. 



C. Beak received in or upon the breast in a pectoral groove confined 

 to prosternum; beak long; tarsi dilated; front coxae contiguous. — 

 Conolrachelus. 

 CC. Pectoral groove extending into the mesosternum, sharply 

 limited behind; front coxas not contiguous; metathoracic epimera 

 distinct, mesosternum feebly emarginate. — Tyloderma. 



