53 
upon a common cruciferous weed, the prairie wall flower {Erysimum 
parviflorum). 
Brief mention is made of this insect by Dr. Fletcher in the Trans- 
actions of the Royal Society of Canada for 1899-1900 (vol. V, 2d ser., 
p. 212). 
NATURAL HISTORY. 
From the sources of information that have been furnished, it 
appears that eggs are laid normally in autumn, although sometimes 
earlier, and that the species hibernates in this stage. The larvae 
hatch in early spring long before cultivated crucifers appear above 
ground. According to Dr. Fletcher, the, larvae feed both in the day- 
time and by night, and are comparatively active, although, as is well 
known, the larvae of the larger leaf -beetles are mostly rather sluggish. 
When disturbed they drop from their food plant. 
The beetles seem to make their first appearance in the Northwest 
Territories during July and August, and do their worst injury through- 
out September, continuing in the field in some instances as late as 
October. The occurrence of the beetles in the latter part of June, as 
noted by Mr. Gregson, at Waghorn, is perhaps rather exceptional. 
Eggs are laid in clusters, loosely fastened together in the same 
manner as those of the Colorado potato beetle, and are deposited 
under clods or in cracks in the soil in similar locations. 
Larvae have been noticed to bury themselves in the earth to a depth 
of about an inch, and to change at once, in small smooth cavities, to 
pupa?. 
REMEDIES. 
The measures to be employed for the destruction of this turnip 
beetle are practically the same as those used against the Colorado 
potato beetle. Paris green is the best of these, and may be applied 
dry, mixed with from ten to twenty parts of cheap or spoiled flour, 
fine plaster, or air-slaked lime; or as a spray, mixed with lime or 
Bordeaux mixture at the rate of a quarter of a pound of the Paris 
green to 40 gallons of the diluent. In order to insure success, where 
the insect abounds in great numbers the wild food plants of the insect 
should also be treated. 
Hand-picking or jarring the beetles from infested plants into pans 
or other receptacles containing a little water on which a thin scum of 
kerosene is floating may also be employed. It follows, as a matter of 
course, that rotation of crops is advisable; and the planting of crops 
subject to the attack of this species, particularly crucifers, should be 
avoided in the vicinity of wild plants affected by the same species. 
