I02 



THE CEREALS IN AMERICA 



spikes when harvested, and are believed to survive in the straw for months without 

 food or moisture. 



Preventive measures are (i) the burning of chaff and screenings as soon as the 

 wheat is threshed, and (2) deep plowing of stubble field to bury the larvae and pupae 



155. The Wheat Plant-louse. — This insect appears on winter wheat in 

 September, going through several generations in the early fall but doing little damage. 

 If the spring is cool and moist, its natural enemies inay fail to hold it in check and 

 it may then cause considerable damage. Extensive damage has occurred only at 

 rare intervals, as in i86x and 1899.1 No effective remedy has yet been suggested, 



156. Insects Injurious TO Stored 

 Grain. — While upwards of forty differ- 

 ent species of insects occur in grana "ies, 

 the following four species are the most 



Beetle and larva of the granary weevil. 

 (After Chittenden.) 



mjunousrss 



(i) The granary weevil {Calaridva 

 gr anuria L.) 



(2) The rice weevil {Calandra oryza L.) 



(3) The Angoumois grain moth {Sitot- 

 roga cerealella Oliv.) 



(4) The wolf moth {Linta granella L.) 

 The first two are beetles and the last two moths. The larvae of the first three 



live within the grains, as (ip the adults of both weevils. This adds very much to 



their injurious effects, to the ease with which they may 



be distributed, and the difficulty of eradication. All 



breed more rapidly in warm than in cold weather and 



consequently do their greatest damage in the southern 



sections of the country, where they cause enormous losses. 



The simplest and best remedy is the use of bisulphide 

 of carbon at the rate of one pound to one ton of grain or 

 in empty rooms for every 1,000 cubic feet. 



There are a number of insects injurious to flour. 

 The Mediterranean flour moth {Ephestia kueJmiella Zell.) 

 has recently become a most serious pest, requiring 

 the adoption of extensive precautions in flouring mills to guard against its ravages. 



Adult and larva of the 

 Angoumois grain moth. 

 (After Chittenden.) 



II. HARVESTING AND PRESERVATION. 



157. Date of Harvesting. — The wheat harvest of the United 

 States begins in Texas in May and ends in the Dakotas in 

 August. In California the hai-vest begins about June ist and 



1 U. S. Dept. of Agr., Farmers' Bui. 132, p. 24. 



2 For a description and life history of these insects see U. S. Dept of Agr, 

 Farmers' BuL 45. 



