70 
They have received this name because they produce. blisters 
upon a delicate skin, being in fact closely related tothe Span- 
ish fly, so well known in former times, and even now, as avery 
important means to draw blisters. Our blister-beetles can be 
used for the same purpose and are bought by manufacturing 
chemists. 
CABBAGE INSECTS. 
The cabbage plant, in allits numerous varieties, has a large 
number of insect enemies, besides other organisms which cause 
the plant to suffer anddie. Among the more destructive in- 
sects that feed upon the cabbage and allied plants, we have a 
number of moths and butterflies that cause great losses. As 
soon as the young cabbage is transplanted, it is attacked by 
various species of cut-worms, which, in most seasons, cut off a 
large percentage of the young plants, thus necessitating re- 
planting, These cut-worms, as will be shown elsewhere, 
can be prevented from doing much damage by the use of tin 
collars. As soon as the young plants acquire a good stand in 
the soil, other winged enemies appear. Chief among them are 
two white butterflies that may be observed flying about during 
the first warm days of spring. They are indeed harbingers of 
spring and they delight the eyes of all observers so much more 
because insects of all kinds have been absent for the last six 
months. These butterflies, though apparently such frail ob- 
jects, can stand a great deal of ill treatment at this period. It 
is not uncommon to find them frozen and apparently dead, yet 
they recover as soonas the rays of the sun warm them back to 
life. There are two species of such butterflies common every- 
where in our state. Both are white, with black markings and 
more or less yellow on the under side. One of these species is 
the native cabbage butterfly (Pieris protodice Bd.—Lec.). Itisa 
very pretty insect, as shown by the illustration (Plate 8, a tod). 
The sexes differ greatly and seem to belong to different insects, 
as may easily he seen by comparing their pictures. The sec- 
ond species (Plate 7, a to d), isthe imported cabbage butterfly 
(Pieris rape Linn.), an insect that, like the English Sparrow, 
has already driven away the native species in many places, and 
is doing so now in our state. It was imported into Canada in 
1857, whence it spread very rapidly in all directions, becoming, 
