214 



THE AMERICAN ENTOMOLOGIST. 



principle of forcing the licjuid through a 

 crescenl-shaped slit or broad lips of vari- 

 ous dimensions, whether cut into a moulded 

 nozzle or made by soldered pieces of tin 

 or zinc, is a most valuable one, not only 

 because of the fineness of the mist that 

 can be produced, but because of the re- 

 duced risk of filling up or clogging. 



FURTHER NOTES AND OBSERVATIONS ON THE 

 ARMY WORM. 



\^Concludeii from p. 185.] 

 HOW FAR IS BURNING OVER A PREVENTIVE. 



That fields which have been burned over 

 in the winter are free from the destructive 

 presence of the worm is a fact in the history 

 of its visitations. But opinion has varied 

 as to the precise effect produced by the 

 burning over. I have shown that it de- 

 stroys the appropriate nidus for the laying 

 of the eggs by the moth in the spring. 

 Now that larval hibernation is established, 

 we can readily see that the fires would de- 

 stroy these hibernating larvae and prevent 

 the appearance of the moths and of a sec- 

 ond destructive brood from them. But we 

 must not suppose that the burning over 

 would prevent all appearance of the worm; 

 it merely prevents its appearance in de- 

 structive numbers. The moth will, when 

 exceptionally numerous, lay her eggs with- 

 out concealment and upon plants, such as 

 clover, which the larva does not relish.* 

 In such cases of exceptional abundance 

 we may well suppose that the moth will fly 

 into fields which had been burned over 

 and supply them with eggs, but the in- 

 stances in which this would result in mate- 

 rial damage to the crop would be very rare. 



CONNECTION OF WET AND URV SEASONS 

 WITH ARMY WORM INCREASE. 



That the army worm appears in de- 

 structive numbers after a period of dry 

 seasons is a fact already recognized, and 

 is in accordance with the experience of the 



* I h.ave recently received from Prof. I.intner, State Ento- 

 mologist for New York, what are apparently the pressed eggs 

 and egg shells of this moth, thickly covering clover leaves, 

 and mixed with an abundance of white gummy matter, with 

 which the moth usually secretes them, all indicating that in 

 this instance the moths (doubtless from excessive numbers) 

 had "slopped over." Prof. Comstock likewise informs me 

 that he has found the eggs laid between the folded lobe of a 

 clover leaf. 



present year. The portions of our country 

 visited by the worm this year were afflicted 

 with drought last summer, and the winter 

 was remarkable for its mildness and tjie 

 slight fall of snow. Fitch's theory of the 

 appearance of the worm reijuired that this 

 spring should be a wet one in order to 

 drive the moths from the swamps and 

 cause them to lay their eggs on the up- 

 land. But the facts are just the reverse. 

 Farmers from Virginia to Vermont have 

 complained loudly of the excessive drought. 

 Rivers in some of the Atlantic States have 

 not been so low for a generation, and allu- 

 vial meadows which have been subject to 

 a spring flooding, have this year remained 

 dry. These facts clearly disprove Fitch's 

 theory, and we must believe that the army 

 worm is most likely to appear after dry 

 seasons, regardless of the wetness or dry- 

 ness of the season in which it occurs. A 

 critical examination of Fitch's arguments 

 in supjjort of his theory shows that lie not 

 only had no personal acquaintance with 

 the worm, but also made some false meteor- 

 ological deductions, such as comparing 

 the rainfall of India (?) with the appearance 

 of the worm here. With equal reason 

 might we argue that 1879 was wet in our 

 Atlantic States because of the excessive 

 ])recipitation in the British Islands during 

 that year. It is evident that Fitch was 

 hard pressed for arguments to support the 

 theory. That the season of 1861 was re- 

 markably wet in the Eastern States, Fitch 

 gives no evidence, and while the mean 

 rainfall, according to statistics was greater 

 in 1 86 1 than in i860, it does not follow 

 that the spring and early summer of 1861 

 were, on that account, unusually wet. 

 From the well known connection of the 

 presence of plant lice with dry seasons, 

 and from the memorable dejjredations of 

 the grain aphis in that year throughout the 

 Middle and New England States, it is very 

 {(uestionable whether the summer of 1861 

 was wet. It is far more probable that the 

 season was a dry one like the present, in 

 which also various plant lice have done 

 great damage. 



The view that the army worm has its 



