16 BULLETIN 256, U. S. DEPARTMENT OE AGRICULTURE. 
HATCHING. 
When the egg is ready to hatch, the lateral halves split at their 
juncture along its edge for about one-third the length from the 
upper end. the nymph slowly forcing itself through the opening 
thus made. 
EXEMIE5 OF THE EGG. 
The greatest natural check to the increase of the angular-winged 
katydid in California is the egg parasite. Anastatus sp.. already 
referred to in connection with Scudderia furcata. Anastatus para- 
sitizes a large percentage of all eggs deposited by this insect each 
year. It is quite usual to find large batches of katydid eggs, each 
egg showing the small, circular exit hole of the parasite (PL IV, 
fig. 1). It is. in fact, rare to find eggs of this katydid entirely free 
from evidence of parasitism. Anastatus oviposits in the katydid 
eggs in September and October, the larva feeding upon the egg 
contents during the remainder of the fall and the adult emerging 
the following spring. All reared specimens have emerged between 
March 19 and May IS. It seems probable that SO per cent or 
more of all eggs deposited by M. rhombifolium are destroyed by 
this little insect. For example, a lot of eggs collected in widely 
separated locations in the fall of 1911 produced 43 adult Anastatus. 
representing 86 per cent parasitism. Of another lot of 109 eggs 
35 per cent produced Jiving parasites and the remainder failed to 
hatch. 
The Xtmph. 
description of ixstap.s. 
The nymph of the angular-winged katydid may be easily distin- 
guished from that of the fork-tailed katydid by its plump body and 
highly arched back, which gives it a decidedly humpbacked appear- 
ance. The nymphs vary in length 
from one-sixth to three -fourths 
inch, depending upon the stage 
of development. Their color is 
grass-green throughout, including 
the long, threadlike antenna?. 
There are six periods of develop- 
ment, or ins tars, which may be 
described as follows: 
Fig. 11.— The angular-wmged sarydid ^incrocen- 
trum rhomt . : First - instar nymph F USt instOT (,fit{. 11). MeasUTe- 
ridBaL) ments: Length of body. 4 mm.; 
length of head (vertex to tip of jaws). 2 mm.: length of pronotum, 
0.72 mm. : length of posterior femur. 4.75 mm.: length of posterior 
tibia. 5 mm.: length of antenna. 16 mm.: subovate. convex along 
dorsum and nearly flat along ventral surface. Color grass-green, 
