338 



ECONOMIC ENTOMOLOGY 



Eggs. — Minute, white, deposited in cavity of kernel. 

 Larva. — Small, robust, whitish, legless; one larva to a kernel of 

 wheat, but several in corn. 



Pupa. — White, clear and transparent. 



Control. — Superheat for 6 hours at i2o°-i2 5°F.; fumigate with 

 hydrocyanic acid gas or carbon bisulphide. 



The Rice Weevil (Calandra oryzce) 

 is also of economic importance, espe- 

 cially in the South (Fig. 218). 



Com Bill-bugs (Sphenophorus spp.). 

 — Adults. Snout-beetles, dull black, 

 surface marked with small pits and 

 narrow grooves; irregularly oval and 

 rounded; }i-^ inch long; hibernate 

 under rubbish; single brooded (Fig. 219). 

 Eggs. — Laid in May and June in 

 roots and stems of grasses. 



Larva. — Thick-bodied, oval, footless 

 grub, with a hard brown head; feeding 

 in corn stem or in root bulbs of grasses; 

 June-August. 



S. maidis. — Does injury to corn 

 both as grub and adult. The grub 

 burrows in lower part of stalk, and the 

 adult occupies the burrow. Other 

 in the leaves of xorn. 



Fig. 219. — The maize bill-bug 

 {Sphenophorus maidis) . Pour times 

 enlarged. 



species make holes and slits 



SCOLYTID^ OR IPID^ (BARK-BEETLES) 



Three common Fruit Bark-beetles are Eccoptogaster rtigulosus, 

 Phthorophloeus litninaris and Anisandrus Pyri, which may be dis- 

 tinguished by the following characters: , . 



A. Venter of abdomen with caudal part bent abruptly upward. 

 Antennal club flat and marked by angulated sutures. — Eccop- 

 togaster rugulosus (Fruit-tree Bark-beetle). 

 AA. Venter of abdomen normal, regularly curved. 



B. Antennal club lamellate, of three separate, laterally pro- 

 duced segments ; head visible from above. — Phthorophloeus 

 litninaris (Peach-tree Bark-beetle). 



