92 
EXPERIMENTS WITH THE EUROPEAN CABBAGE WORM. 
(.Pleris rapes L.) 
Fig. 15— European Cabbage butterfly, male. Fig. 1G.—European Cabbage butterfly, female. 
Whenever any species of noxious insect becomes 
abundant enough to attract general attention, the 
agricultural press, the proceedings of agricultural 
societies, and the conversation of those interested, 
commences to teem with recommendations of reme¬ 
dies. If one attempts to collate these various recom¬ 
mendations, he is at first surprised, then bewildered, 
then discouraged and disgusted at the number of 
substances which his list will include and the ab¬ 
surd and contradictory statements made concerning 
them; and he commonly finds himself thrown back 
at last upon the results of his own individual experi¬ 
ments. While the recommendations made are many 
of them of the highest value, the difficulty is to dis¬ 
tinguish the useful from the worthless in the absence 
of any exact and sufficient knowledge of the facts on 
which they rest. 
Under these circumstances, it evidently becomes one of the duties 
of the State Entomologist not only to make careful and elaborate 
experiments for the destruction of noxious insects, and to embody the 
results of these experiments in the form of recommendations, but also 
to give in full the evidence upon which his recommendations rest, in 
order that each may see for himself the amount and value of the 
proof. 
No better illustration of this fact could have been selected 
than the European cabbage worm; and I have consequently taken 
pains to experiment with a few of the substances most generally 
recommended for the destruction of that pest. It was, of course, im¬ 
possible to make a thorough trial of any considerable number in the 
Fig. 17.—European 
cabbage worm 
and chrysalis: a, 
larva; b, chrys¬ 
alis or pupa. 
