SEQUENCE OF GIPSY-MOTH PARASITES IN EUROPE. 131 
as enemies of the gipsy moth. Of them all, not one refused to attack 
and devour the caterpillars and pupe of the gipsy moth with business- 
like dispatch, once given an opportunity, but with one or two excep- 
tions none has shown a disposition to climb trees in search of its prey. 
Being essentially terrestrial in habit, they were essentially unfitted 
to prey upon an essentially arboreal insect. 
We know little of the predatory beetles which are to be found in 
that part of France which was visited upon this occasion, nor does 
this lack of knowledge vitiate the strength of the argument to any 
great extent. The fact was that if present (and undoubtedly some 
species are to be found) any of the numerous forms which have been 
studied at the laboratory and discarded as unfit for the purposes de- 
sired in Massachusetts would immediately assume high rank as ene- 
mies of the gipsy moth. In other words, the conditions under which 
the gipsy moth exists in southern France are wholly incomparable with 
those under which it exists in New England, and the agencies which 
are effective in accomplishing its control are likewise incomparable. 
The unimportant role obviously played by the parasites immediately 
loses its significance. Those species of true parasites which assist in 
this control are practically the same as those which assist in other 
localities, but the demand upon them and their opportunities for mul- 
tiplication are insignificant compared to those existing in Massachu- 
setts, if they are ever established there. True to their character as 
agencies in facultative control, they do not increase in efficiency to an 
extent which would practically mean the extinction of their host. 
The results of the rearing and dissection work carried on at the 
laboratory indicated that a parasitism varying from 25 per cent to 
something in excess of 40 per cent prevailed in this locality. After 
seeing the conditions under which the gipsy moth struggled for ex- 
istence, real wonder was felt that it should be able to survive, and the 
trip resulted in a firmer conviction than ever in the efficacy of para- 
sitism, and the validity of the theory upon which the parasite-intro- 
duction work was conceived. | 
SEQUENCE OF PARASITES OF THE GIPSY MOTH IN EUROPE. 
The parasitic fauna of the gipsy moth varies considerably in various 
faunal divisions of Europe, and no attempt has been made to prepare 
separate lists of the parasites peculiar to those regions which have 
been represented in the material imported. In Table II, which is con- 
structed in accordance with that representing the sequence of para- 
sites in Japan, as explained on page 122, all of the various species reared 
from the European material are listed. As in the table of Japanese 
parasites those species which are of no consequence in the control of 
the moth (so far as known) are marked with an asterisk. 
