6 BULLETIN" 256, XT. S. DEPARTMENT OF AGRICULTURE. 
winter rains. If, however, the leaves are kept perfectly dry, a large 
percentage of the nymphs fail to extricate themselves from the egg- 
shell. This observation suggests the possibility that the species 
may successfully pass the winter in the egg stage even in deciduous 
leaves and in its most northerly range, provided these leaves are 
sufficiently protected from freezing by a covering of dead leaves and 
snow. 
INCUBATION PERIOD. 
Eggs have never been observed to hatch during the year they were 
deposited, and in the San Joaquin Valley they invariably pass the 
winter in the leaves on the citrus tree. The average duration of the 
egg stage, as determined in 1911 and 1912 from 68 eggs deposited 
between July 14 and August 6, was 286 days. Eggs deposited in 
July averaged about 290 days; those deposited in August, about 275 
days. Those deposited later in the year undoubtedly have a shorter 
duration, since the period of hatching for all is short. In general, 
the incubation period lasts from the maximum period of deposition, 
about the middle of August, to the maximum period of emergence, 
which, in 1912, was about the middle of May, or 275 days. 
ENEMIES OP THE EGG. 
A small chalcidid parasite, determined by Mr. J. C. Crawford as 
belonging to the genus Anastatus, is the most important, and indeed 
the only enemy of the egg discovered during the investigation. 
This parasite, though perhaps the most important natural check to 
the species, is much more effective in checking the angular- winged 
katydid, to which it largely confines its attacks. On March 22, 1912, 
a quantity of orange leaves, each 'containing one or more eggs of 
S.furcata, was gathered and kept in condition for the hatching of the 
eggs. On April 2 adult parasites began to emerge from these eggs 
and continued to do so for one and one-half months, or until May 18. 
The proportion of eggs parasitized in the lot under observation was 
25 per cent. The eggs were taken at random from all parts of an 
orchard, and it seems reasonable to assume that fully 25 per cent of 
all the eggs in this orchard were parasitized. 
General appearance of adult parasites.— -The little parasites run- 
ning over the orange leaves resemble small, winged black ants. 
They are very active, glossy black, reflecting metallic bronze-green 
in the sunlight. They have two pairs of membranous wings, the 
fore pair in the female being almost covered by a large, brownish 
spot; both pairs are transparent in the male. The female is about 
one-eighth inch long, the male considerably smaller. Only one 
parasite issued from a single katydid egg in any case observed. The 
insect escapes from the side of the parasitized egg. The oviposi- 
tion of Anastatus has not been observed. 
