36 ENTOMOLOGICAL NEWS [Jan., '15 



Army Worm Plague in Philadelphia (Lep.). 



The army worm (Leucania unipuncta), the moth of which is always 

 more or less common around Philadelphia, proved a veritable plague 

 last year (1914). The first brood of the moth made its appearance 

 about the twentieth of June. The young worms were noticed by the 

 writer about July sixth, but the general public did not notice them 

 until about July fifteenth, at which time the worms were from one- 

 quarter to three-quarters of an inch in length. There was scarcely a 

 section of Philadelphia that did not have more or fewer of the worms. 

 Newspapers, of course, exaggerated the matter, although it was bad 

 enough. I visited a number of places where the worms were said to 

 number in the thousands, but in many cases found they could be num- 

 bered in the hundreds. In some gardens I found plenty of worms, 

 while in adjacent gardens none were to be found. Investigation in 

 most cases showed that the gardens seriously affected were those 

 that were not kept in order long grass and weeds having full pos- 

 session. Contrary to the generally accepted theory, that the worms 

 ate the grass clean down to the ground, I found that they often left 

 from a quarter to a half inch of the base of the grass blade remain- 

 ing. It has been noticed that the army worm ofttimes becomes a plague 

 when a wet season follows a dry one, and this was just the condition 

 of affairs around Philadelphia last year. Our spring was unusually 

 dry, little rain fell during the month of April, and only four and a half 

 inches during the two months of May and June. July was just the 

 opposite, seven and three-quarter inches of rain falling. The majority 

 of worms reached their full growth about the first of August. The 

 moths from these worms started to emerge from the pupa about the 

 eighth of August, the great majority emerging between the tenth and 

 thirteenth. The moth is attracted to the electric light, but not to such 

 an extent as one would suppose, considering the number of moths 

 there are around. While sugaring for moths, Leucania unipuncta often 

 proves a nuisance, coming in such numbers to the bait as to preclude 

 the more desirable moths that the collector wishes to secure. The 

 second crop of full grown worms was observed around the eighteenth 

 of September, but they were so few in number that the general public 

 did not notice them. Spraying with a mixture of arsenate of lead and 

 water, and the sieving of dry slacked lime over the places infested, 

 was found to be effective in destroying the worms. A mixture of 

 Paris green and bran was recommended, and used to some extent, but 

 some of our bird friends objected to this method, claiming that many 

 of our birds lost their lives through its use. PHILIP LAURENT, Mt. 

 Airy, Philadelphia. 



