30 PARASITES OF GIPSY AND BROWN-TAIL MOTHS. 
duction to any one of the different countries to which it has been 
carried. Its success has been more perfect than that of any other 
beneficial insect that has so far been tried in this international work. 
There are good reasons for this—reasons that do not hold in the 
relations of many other beneficial insects to their hosts. In the first 
place, the Icerya is fixed to the plant; it does not fly, and crawls very 
slowly when first hatched, and later not at all. The Novius, however, 
is active, crawls rapidly about in the larval state, and flies readily 
in the adult. In the second place, the Novius is a rapid breeder, and 
has at least two generations during the time in which a single genera- 
tion of the host is being developed. In the third place, the Novius 
feeds upon the eggs of the Icerya. And in the fourth place, it seems 
to have no enemies of its own. ‘This is a very strange fact, since other 
ladybirds are destroyed by several species of parasites. For example, 
as will be shown later, native American ladybird parasites brought 
about a great mortality in the larvee of the Chinese ladybird imported 
from China into America at a later date by Marlatt. The hymenop- 
terous parasites of the widespread genus Homalotylus feed exclu- 
sively in ladybird larve, which are frequently also fairly packed with 
the minute hymenopterous parasites of the genus Syntomosphyrum, 
while the adults are often destroyed by Perilitus, Microctonus, and 
Kuphorus. 
The astonishing results of the practical handling of Novius drew 
attention more forcibly than ever before to the possibilities of this 
kind of warfare against injurious insects, and although its perfect - 
success as an individual species has never been duplicated, very 
many efforts in this direction have been made, some of which have 
met with measurable success and some with very positive results of 
value. 
INTRODUCTION OF ENTEDON EPIGONUS WALK. INTO THE UNTED STATES. 
In 1891, with the assistance of Mr. Fred Enock, of London, Riley 
introduced puparia of the Hessian fly (JMJayetiola destructor Say) 
infested with the chalcidid parasite Entedon epigonus Walk. into 
America. These were distributed among several entomologists dur- 
ing the spring of 1891. One American generation was carefully 
followed by Forbes in Illinois, and four years later (in May, 1895) 
the species was recovered by Ashmead at Cecilton, Md., where a 
colony had been placed in 1891. Thus the introduction was appar- 
ently successful, but if the species still exists in the United States 
it must be rare, since extensive rearings of Hessian-fly parasites have 
been made by agents of the Bureau of Entomology in many different 
parts of the country during the past few years and not a single speci- 
men of the Entedon has been recognized. The Maryland locality, 
however, it should be stated, has not been visited by an entomologist 
since Ashmead’s trip in May, 1895. 
Pe 
