212 Fiftieth Report ox the State Museum 



Encouraginf^ natural enemies. — Among the most beneficial may be 

 counted many of our insectivorous birds. They have repeatedly been 

 observed feeding on the army-worms in badly infested fields. If the 

 grain fields are not sown too thickly, not only is a better crop secured, 

 but the birds, having more wing room in the grain, will feed to a much 

 larger extent on the caterpillars. Unfortunately, little can be done 

 toward encouraging the insect enemies of the army-worm beyond pro- 

 tecting them so far as possible, and giving them the favorable conditions 

 that may attract them. 



Watching for indications. — The measures given above are not to be 

 depended upon entirely, even though carried out to the letter. They 

 should be supplemented by watchfulness. If the army- worm commences 

 its operations in a field in unusual abandance, it is of the utmost import- 

 ance that Its presence should be known at once. The discovery is usually 

 made, and advice sought in the matter, when it is too late to save more 

 than a scanty half or less of the crop attacked. It is not a difficult task 

 to discover the caterpillars some days before they are usually seen, and 

 no man should begrudge the time devoted to the search. The thickest 

 portion of a field should be examined for their small black or brown 

 droppings, and the condition of the lower leaves of the grass or grain 

 noticed. If the leaves are injured or absent, something has been eating 

 them. The enemy may be found hidden under loose shelter of any kind 

 on the ground or just below the surface, or when very small, upon the 

 plants. If they are discovered before serious injury has been done to the 

 crop, it is comparatively easy to decide whether or not to cut it at once. 

 If the field is thickly infested, they will destroy the crop unless it is taken 

 from them. 



The commencement of an army-worm attack, as above noted, will 

 rarely be detected. It is only when their operations can no longer be 

 hidden from ordinary observation that alarm is excited, and the necessity 

 of active measures for arresting their destructive marches from field to 

 field becomes apparent. Some of the following measures will then be 

 found of service : 



Lime., dust^ etc. — If the army-worms are numerous in a field — at an 

 early stage in their operations, it would probably be wise to cut the 

 crop at once and save what is left of it, although air-slaked lime, land 

 plaster, or even road dust freely distributed over the vegetation when it 

 is wet with dew or rain, would render it unpalatable to the caterpillars 

 and compel them to seek other food. 



