BARRA ARE PM ERR EEE PE EB OO BPR Pee tee 
THE HORSE-RADISH FLEA-BEETLE, 13 
to be no way to destroy it. It is very small, yellow with black stripes, and it 
hops; inside of the leaves there are about 25 or 50, according to the size of the 
jeaf. They do their damage when the horse-radish first sprouts after planting, 
eating off the sprouts as they come up. We have for years hauled out all old 
dead leaves, after marketing the horse-radish, and burned them. Paris green 
kills the leaves; kerosene solution does not kill the bug. Every year I plant 
about 35,000 plants, and the last two years only about 8,000 developed ; besides 
the loss, I have less and less plants each year. There are several planters who 
have lost their entire crop on account of this insect. 
NATURAL ENEMIES. 
No parasite or disease of any sort has been observed in the field or 
in confinement. This is undoubtedly an oversight, since other flea- 
beetles have natural enemies, such as parasites of the adults, and in 
time these will probably come under observation. From Glencoe, Il., 
a larva apparently predacious on the larva of this species was received. 
ASSOCIATED INSECTS. 
Associated with this’species at Madison, Wis., were three species 
of minute maggots, (4lachiptera) Crassiseta nigriceps Loew, Oscinis 
pallipes Loew, and Agromyza scutellata var. variegata Meig. The 
first was found in horse-radish stems with the flea-beetle, and adults 
were reared from larve boring in the same stems, often in the same 
tunnels, as the flea-beetle larva. The third species was reared in 
horse-radish flea-beetle rearing cages with the preceding. This and 
probably one or more related species have often been reared from 
horse-radish stems both at Green Bay, Wis., and Madison, Wis., but 
just what part they play in the economy of this beetle is unknown. 
The adults frequently annoy the beetles by flying around and appar- 
ently attempting to alight on them. 
METHODS OF CONTROL. 
SPRAYING. 
The injurious flea-beetles of the group to which this species belongs 
have never been satisfactorily treated by means of insecticides, to the 
knowledge of the authors. The same applies to other groups of small 
flea-beetles which attack solanaceous plants, like potato and egg- 
plant. The powerful hind legs which enable these insects to Jump 
like fleas assist them in escaping from plants during spraying op- 
erations, and it is a matter of general knowledge among practical 
entomologists that it can not be very well determined how much 
poison, if any, they obtain by feeding on the poisoned surface of 
leaves. Many experiments have been made, and in practically every 
case the results have been negative. On the other hand, where Bor- 
