4(i THE REPORT OF THE No 19 



and E. vittata. Of these Epicanta rittata was perhaps most commonly seen. All are rather 

 soft-bodied insects, and may be distinguished by their color. E. Pennmjlirudca (fig. 21 b) is 

 uniformly black ; E. cincrea (fig. 21 o) is blackish with grey streaks along the margins of wing 

 covers and middle of thorax ; and E. rittata (fig. 22) yellowish with black stripes. The stripcfl 

 species was present in large numbers on beet crops; the ash-colored sjjecies on vetch, hoi .si 

 beans, lucerne, and the black blister beetle on Golden Rod. 



VVhen the life-history of blister beetles is studied it is found that their larvie prey up n 

 grasshoppers, and hence are beneficial. A question, therefore, arises : " Should we destmy 

 the beetles and ti-y to lessen their numbers?" It must be understood that the more adults we 

 kill the fewer larv;e will develop to destroy the eggpods of grasshoppers, and the greater the 

 number of grasshoppers aj)pearing the foUnving season. When these factors are borne in 

 mind there is good reason for allowing the adult beetles to feed unmolested. They never 

 remain long enough to do much serious injury. They usually appear in large numbers for a 

 week or ten days, but they disappear as suddenly. It is a matter of observation that blister 

 beetles are more numerous than usual the season following one when grasshoppers were very 

 'abundant. 



Before the advent of the Colorado Potato Beetle these blister beetles were the "potato 

 beetles." In many districts in the northe-n pirt of the province they are still the "potato 

 beetles." 



Plant Lice. 



Plant lice, or Aphids, (Fig. 23), were more abundant than usual this past season. The 

 early spring with its moist, cloudy weather was strongly in favor of their rapid development : 

 and among the more common forms that did considerable mischief were the Cherry Aphis 

 (il///iu.s cerasO, Apple Aphis {Aphis mali). Plum Aphis (Aphis prunicola), Currant Aphis {Myzv.< 

 rihis), the Rose Aphis, and the Grain Aphis. As Aphids are sucking insects, that take their 

 nourishment in the form of plant juices through a slender tube, arsenical poisons on the plants 

 have no effect. Frequently the presence of a few plant lice in the early part of the season is 

 altogether neglected, when a little trouble at that time would practically exterminate them. 

 Many persons are unwilling to believe that from a few Aphids tens of thousands of them will 

 develop before July. Huxley once computed that " the uninterrupted breeding of ten genera- 

 tions of plant lice from a single mother would produce a mass of organic matter equivalent to 

 that of 500 million of human beings." As Dr. Howard remarks, this great productivenesses due 

 more to the early age at which the Aphids begin to reproduce, rather than to any extrena 

 prolificacy. 



The majority of the generations or broods produced during the summer are wingless, but 

 at intervals winged broods occur. This is very probably a provision for the distribution of 

 the species. The last brood of the season is a winged one, compo'sed of both males and 

 females. Soon after mating the males die, while the females perish after the deposition 

 of the eggs. 



Plant-lice have possibly more enemies, which feed upon them, than most other injurious 

 insects. These enemies are Lady-birds, Braconids, Aphis lions, maggots of Syri)hus-fiies, and 

 certain other dipterous maggots. All of these kill immense numbers of Aphids, and in some 

 instances exterminate them, but in most cases extreme rapidity of development more than 

 counterbalances great mortality. 



The Cukkant Anus {Mii::vs rifiis). 



Althou,di never a serious pest, this Aphis disfigures and renders unsightly the leaves 

 o" currints. Attention is here called to it on account of the many inquiries. 



