250 Bulletin 133. 



The Next Army-worm Year. 



Will the army-worms come again next year ? In 1896, this was 

 the question uppermost in the minds of many New York farmers 

 whether they suffered from the ravages of the insect during the 

 year or not. This spring there are reports from some localities 

 in the state that farmers are planning to not sow oats and other 

 grains for fear of another invasion of the worms this summer. 

 Of course, no one can say definitely when New York crops will 

 again be ravaged by the pest. Many of our insect foes may come 

 one year in very destructive numbers, but it often happens that 

 the next season we see or hear very little of them. The preval- 

 ence of insect life may be likened to a pendulum that swings 

 irregularly in response to the action of some of nature's forces ; 

 in the case of insects, their parasitic and predaceous enemies and 

 the variation in their food supply and in climatic conditions are 

 among these forces. However, man has not yet been able to 

 formulate these " ups and downs " so that he can rarely predict 

 with any certainty whether an insect will appear in injurious num- 

 bers at any time, even though it may have appeared in very 

 destructive numbers only the year before. This is especially true 

 of the armj^-worm. No one can predict when we will or will not 

 have an * ' army-worm year. ' ' It has been noted that often an 

 outbreak of the worms has occurred during years which had an 

 unusually dry spring and were preceded by an abnormally dry 

 year ; a dry spring gives a more favorable opportunity for the 

 development of the little hibernating caterpillars and those which 

 may hatch early from eggs laid by moths which hibernated. But 

 this combination of climatic conditions does not invariably bring 

 army-worms in injurious numbers. 



Since 1825, the insect has appeared in injurious numbers some- 

 where in the country nearly every year. It has also been injuri- 

 ous somewhere in New York state at intervals of from one to 

 three years since 1872. But, and here is an important historical 

 fact, rarely if ever, has it ravaged crops i7i the samelocaliiy during 

 two years in succession. There has been only three general out- 

 breaks of the insect in New York ; those occurred in 1861, 1875, 

 and 1880. The other outbreaks were mostly confined to a county 



