ASPARAGUS BEETLES AND THEIR CONTROL. 11 



SPRAYING APPARATUS. 



Extensive experiments have proved that for economy and efficiency 

 the best spraying machinery should be used, even though its initial 

 cost is greater. The "vermorel," ''cyclone/' and "giant-disk" types 

 of nozzles are the most effective as well as the most economical. Wlien 

 the arsenical is forced through a nozzle of any of these t3^pes the spray 

 is mistlike in appearance and adheres to the fohage instead of forming 

 small drops which may roll off. A sprayer of the compressed-air 

 type is the best, the smaller ones being operated by hand and the 

 larger ones by machinery driven by horsepower. 



THE TWELVE-SPOTTED ASPARAGUS BEETLE. 



A somewhat less injurious species than the preceding is the twelve- 

 spotted asparagus beetle ^ known to many growers as the red 

 species. It is generally distributed in Europe, where it is apparently 

 native, and, although common, not especially destructive. Like the 

 preceding, it lives exclusively on asparagus, and its chief damage is 

 due to the depredations of the hibernated beetles in early spring upon 

 the young and ecUble asparagus shoots. Later generations attack the 

 foliage, living, for at least a considerable portion of the larva stage, 

 within the ripening berries. 



INTRODUCTION AND SPREAD IN THE UNITED STATES. 



The presence of this insect in America, as has been stated, was first 

 discovered in 1881 in the vicinity of Baltimore, Md. This beetle 

 was noticed in considerable numbers from the first, showing that 

 it had probably been introduced several years earher. It was then 

 seen only on volunteer asparagus growing on the salty margin of 

 a river, although beds of cultivated asparagus were plentiful in the 

 immediate vicinity. Two years later it had proved even more 

 troublesome than the common asparagus beetle. 



It has been said of this species that it is one of the most interesting 

 insect pests of which we have knowledge. Its mysterious introduc- 

 tion into the United States, the discovery of its presence in Baltmiore, 

 the rapid spread from that center, the keen race northward with the 

 common species, their simultaneous arrival m Canada and progress 

 westward, are only a few of the mterestmg phases of the history of 

 the twelve-spotted asparagus beetle. Nearly every year since then it 

 has been reported in new localities in the United States and Canada, 

 imtil now it is weU distributed westward and northward. In the 

 Niagara peninsula the two specii^s arrived almost simultaneously, 

 the twelve-spotted fonn being the dominant one. 



' C'rioceris duodeci in punctata L. 



