102 



corn-borer) had become established in eastern Massachusetts [see this 

 Review, Ser. A, vi, p. 554], the maize crop being so seriously damaged 

 as to cause the gravest apprehensions should this insect spread into 

 the great maize belt of the middle west. As the insect hibernates 

 in the stalk of the host-plant, winter destruction is possible, though 

 extermination would be a matter of great difficulty and expense 

 owing to the number of food-plants of this moth. An extension of 

 the alfalfa weevil [Hypera variabilis] into Colorado during the summer 

 of 1917 and affecting about 3 square miles is being dealt with by 

 co-operative treatment. In Utah, Idaho and Wyoming, where the 

 weevil has been present for some years, its natural enemies, introduced 

 from Europe in large numbers, have greatly increased and are giving 

 material aid in controlling it. During 1917 considerable damage 

 was done throughout northern Texas by the chinch bug [Blissus 

 leucopterus], but the outbreak of 1918 was subdued partly by the very 

 heavy spring rains, and largely by communal action early in the season. 

 Forage crops throughout the western and north-western states sustained 

 severe and widespread injury by grasshoppers in 1917, the loss in 1918 

 being greatly reduced by the co-operative movement organised 

 against them. A similar campaign in eastern Kansas against the 

 Hessian fly [Mayetiola destructor], in the autumn of 1917, secured the 

 ploughing down of stubble and the general observation of the safe 

 planting date, resulting in greatly improved conditions during 1918. 

 Winter wheat was rather seriously injured by a wheat-infesting 

 sawfly in Maryland, the pest being present throughout that State, 

 as well as in Pennsylvania and northern Virginia. This insect has 

 been identified as Trachelus tabidus, a European species present in 

 Pennsylvania since 1913, and hibernating in the wheat stubble of the 

 current year. 



During the course of stored-product insect investigations under 

 Dr. E. A. Back, arrangements were made with the Quartermaster's 

 Department of the Army whereby food and clothing supplies intended 

 for overseas shipment were frequently inspected by experts, thus 

 rendering possible the detection and check of insect ravages before 

 great loss had been caused. 



Under the direction of Dr. F. H. Chittenden special attention was 

 given under an emergency appropriation of £6,000 to the study of the 

 sweet-potato weevil [Cylas formicarius] in its occurrence in the Gulf 

 States. The methods adopted included a farm-to-farm survey, large 

 scale experiments at field stations, demonstration of eradication projects, 

 and an educational campaign by inspectors. As a result of these it 

 seems probable that the end of another season's work may find the 

 sweet-potato crop of the least-infested of these States to be nearly 

 free from the weevil. The experimental curing of sweet-potatoes by 

 heat has shown the possibility of destroying 95 per cent, of weevils 

 in storage houses by heating the tubers to 115° F. for 8 days. In 

 badly infested districts in Texas, losses due to weevil injury have been 

 reduced from 50 per cent, to less than 10 per cent, by the timely 

 application of arsenical sprays. 



Work against southern field-crof) insects carried out under 

 Dr. W. D. Hunter have resulted in the discovery that the cotton boll 

 weevil [Anihonomus grandis] can be controlled by dusting with lead 

 arsenate or calcium arsenate [see this Revieiv, Ser. A, vii, p. 74]. 



