PARASITES OF GIPSY-MOTH PIT.E. 
253 
tience, but are none tlie less necessary if we are ever to know all that 
is to be known about the subject. 
None of the beetles mentioned is likely to attack the later-stage 
caterpillars, but among the larger Carabida? is to be found a variety 
oi species which arc not only able, but more than willing to destroy the 
lull-fed caterpillars and pupae whenever opportunity offers. There are 
many such in Europe which do not occur in America, and altogether 
a considerable number of different species has been received from 
abroad and tested as to ability to assist in the control of the gipsy 
moth in this country. 
Three characterisl ics in addit ion to ability and willingness to attack 
the gipsy ninth are necessary if the introduction of a beetle is to be 
seriously undertaken as an economic experiment. It must breed at 
the proper season of the year, so that its larva 1 may receive the ad- 
vantage of the practically unlimited food supply which the present 
superabundance of the gipsy moth gives: it must be able to with- 
stand the rigors of the New England climate, and not only the adult 
beetles but their young must be arboreal in habit. An abundance 
of species both native and foreign will feed freely upon the gipsy 
moth in confinement, but of these only a few will seek out the cater- 
pillars or pupa? in the situations in which they are to be found in 
America. The adults of a port ion of t his number do habitually climb 
into the trees in search of their prey, but not all such are similarly 
arboreal during their larval stages. Of those which are arboreal, or 
which appear to be arboreal, during all of their active life, a part 
appear to breed at the wrong season of the year and another part do 
not extend their range into a sufficiently high Latitude to make them 
effective as enemies of the gipsy moth. There is not a single species 
native to America which meets all of the delicate requirements of the 
situation, but such a species has been found abroad in Calosoma si/co- 
phanta L. (See PI. I, frontispiece, adult eggs, larva 1 , and pupa.) This, 
of all of the numerous species of predaeeous beetles which have been 
investigated at the laboratory, bids fair to be of real assistance in 
the fight which is being waged. 
Like all the larger carabids inhabiting the temperate regions, this 
species is terrestrial during a considerable portion of its life cycle, but 
both adults and young, which are equally voracious, climb freely into 
the trees in search of their prey. The eggs are deposited in the earth, 
and the young larvae upon emerging are possessed of a remarkable 
vitality and sufficient strength and cunning to enable them to seek 
out and successfully to attack, when found, the largest and most 
active of the gipsy-moth caterpillars. They also attack the pupae 
with even greater freedom, and once ensconsed within such a mass 
of pupa 1 as is frequently encountered in partially protected situations 
upon a badly infested t ree, will rapidly complete their growth without 
