50 



ENTOMOLOGICAL SOCIETY OF ONTARIO. 



The moths feeding on flowers are more likely to be found near low ground, and hence 

 they appear to come from such place?. There appear to be three generations represented 

 in a setson or two broods in a yetr ; the tint wintering as larvae, the second forming the 

 "Armies," and the third larvae derived from these after the imago has been developed ; 

 the last wintering as larvae. The army worm usually winters in the larval form, but 

 sometimes as the moth. 



In the vicinity of our fields at Guelph, where the caterpillars were so numerous, we 

 have as yet (Oct. 18th) failtd to find any of the second brood. 



The following stages (taken from Ri'ey's report 1882) in the life history of an Army 

 worm gives a good idea of the length of time that elapses in passing from the egg to 

 imago. Eggs laid M*y 4th, hatched May 11th, 1st moult May 17th, 2nd moult May 

 20th, 3rd moult May 23rd, 4th mo alt May 26th, 5ih moult May 29th : pupa June 2nd, 

 imago June 17th. 



At the College the first caterpillars were observed on the 8th of July ; on the 9th 

 there was a preceptible increase, 12th a marked increase; 13th large numbers; 14th, 

 15th still very numerous ; on the 16oh a perceptible decrease ; 17ih the decrease quite 

 marked; 18th, 19th comparatively few; 20ih only a few stragglers could be seen, and, 

 most of these, were light colored. Towards the close of the attack, a bacterial disease 

 seemed to destroy some of them. It is a matter of surprise to many how these caterpillars 

 appear and disappear so suddenly, but a little reflection upon their life history explains 

 the mystery. 



Hidden in the grass by day, and feeding at night, they escape observation. If one 

 or more dry seasons come, they multiply rapidly. Large numbers winter in the larval 

 condition, and during the following spring moths appear and lay many eggs, which hatch 

 and give rise to innumerable caterpillars which from a scarcity of food are forced to "march" 

 and thus become suddenly conspicuous. These develop, pass into the ground to enter the 

 pupa stage, and thus disappear suddenly. 



Dry weaihpr seems favourable for their development. Consequently a dry season, 

 followed by a mild winter, and a dry summer, as in 1895, and 1896", supplied conditions 

 very suitable for increase of the army worm in many parts of Ontario. 



Having referred to the distribution, and life history of this insect, and some of our 

 investigations in connection with it, we miy now direct attention to some of the means 

 by which it is, and may be prevented from being a source of alarm. 



Natural remedies. The army worm has many enemits; nearly all insectivorous 

 birds relish it as a sweet morsel, and are ready to feed upon it the moment it becomes 

 conspicuous. In Guelph, this season, the English sparrows congregated in great num- 

 bers, where the caterpillars were numerous, and fed voraciously upon them. In some 

 parts of the United States the bobolink is called the army worm bird. 



Fig. 47. 

 Tiger Beetle. 



F!g. 4S. 

 (Calosomu calidun.) 

 [After rtiiey ] 



Fig. 49. 

 Ground beetle (Har- 

 pilus califjinosus ) 

 [After Kiiey.] 



Fig. P0. 

 Kemcraca leucaniae. 



The ground beetles, Calosoma calidun, fig 48, and Flarpalus calignosus, fig 49, es- 

 pecially the former, were very numerous in the infested fields. Tiger beetles (Gincin- 



