18 
tiny egg. This egg hatches into a larva in a few days, and the usual 
position in the body of the “ green bug” of the larva up to the time 
it becomes full-grown is shown in fig. 6, page +. Up to this time it 
has fed within the body of the “ green bug” without reaching any 
of the vital parts, but preventing to a greater or less degree the 
giving of birth to young. This is an important fact, for, as the 
parasite seems to prefer partly grown young, it begins to check the 
increase of the pest before the death of the “ green bug ” takes place. 
Mr. Phillips has found that females parasitized at this period of their 
development do not reproduce for more than a very few days. After 
about six days the larva of the parasite reaches full growth and becomes 
more active, working its way about within the still living body of its 
host, which now dies a seemingly terrible 
death. The motions of the parasitic larva 
within cause the skin of the “ green bug” 
to become rotund in shape, as shown in fig. 
9; the skin also becomes darker and 
hardens. Within four days (the life eycle 
in warm weather occupying about ten days) 
the adult Lysiphlebus emerges through a 
round hole in the dried skin of the “ green 
bug,” as shown also in fig. 9. In fields 
that have been destroyed the leaves become 
almost covered by their brown bodies, as 
shown in fig. 7. As stated, many of the 
LSE ‘ oreen bugs ” are stung by the Lysiphlebus 
| Neleraataie el while quite young, and if these develop to 
CELELLELELLELL winged adults, as they do at times in 
Fic. 9—Dead “green bugs,” myriads and drift away to distant fields, 
Ne ey a re they carry the parasite with them in their 
Iebus tritici emerges. The bodies. One of these parasitized winged 
top fe shovs te i sll females is shown in fig. 10 
the bottom figure shows the The very act of migration of the “ green 
ec Sea Enlarged. bug,” therefore, brings the parasite, and 
| there is no need of artificial introduction, for 
if the center from which the “ green bug ” is migrating has the para- 
sites, as it always does, the latter are of necessity carried by their 
hosts, and, furthermore, the adult parasites fly with the latter with 
favoring winds. 
During strong winds the Lysiphlebus does not use its wings, but 
crawls about over the plants and probably does not become scattered 
by gales. But in warm, comparatively still weather the writer has 
observed both winged * green bugs ” and parasites crawling about on 
the windows of railway coaches many miles away from seriously 
infested fields of grain. 
[Cir, 93] 
