8 
BULLETIN" 256, U. S. DEPARTMENT OF AGRICULTURE. 
Fig. 6.— The fork-tailed katydid: Second- 
instar nymph. Somewhat more than 
twice enlarged . ( rigina 1 . ) 
forming the dorsum of the mesothorax and metathorax appear as little 
flap-like, evenly rounded processes folded down over the upper 
portion of the episterna and epimera of their respective segments. 
These semicircular processes are the wing rudiments and are dis- 
tinctly characteristic of this instar. 
Second instar (fig. 6).- — Measurements: Breadth of head, 1.3 mm.; 
greatest breadth of abdomen, 1.4 mm. ; length of body, 6 mm. ; length 
of pronotum, 1:1 mm.; length of posterior femur, 6.1 mm.; length 
of antenna, 14 mm. The markings on 
the body are the same as in the preced- 
ing instar, but the ground color of the 
abdomen is bright green, making the 
spots on it less conspicuous. The small, 
flaplike wing rudiments are now almost 
equilaterahy triangular, with nearly 
pointed and but very slightly rounded 
tips. The bright green color of the ab- 
domen and the triangular shape of the wing-pads readily distinguish 
this stage from the preceding one. Just after the first molt the 
nymph is about one-fourth inch long. 
Third instar (fig. 7). — Measurements: Length of body, 7.4 mm.; 
length of pronotum, 1.55 mm.; length of posterior femur, 7.5 mm.; 
length of antenna, 17 mm. The general color and markings of the 
body are as in the second instar, the intensity of the green coloring 
varying in different individuals. In this and succeeding instars the 
head and abdomen are less broad 
compared with the thorax than 
in instars I and II. The wing 
rudiments are triangular as in 
the second instar, but their hind 
margins extend downward and 
very slightly forward, while the 
front margin extends more 
abruptly backward than in pre- 
ceding stages, thus making the 
sides unequal in length. Faint 
evidences of wing-veins may be distinguished at this stage. Just 
after molting to this instar the nymph is about one-third inch long. 
Fourth instar (fig. 8). — Measurements: Length of body, 10 mm.; 
pronotum, 2.3 mm.; posterior femur, 10.8 mm.; antenna, 24 mm. 
Color as in preceding instar. Whig-pads appressed to sides of meso- 
thorax and metathorax as in preceding instars, but both front and 
hind margins extending downward and backward; posterior pair 
reaching well over on the sides of the first abdominal segment. About 
eight veins can be readily distinguished hi the hind wings and a few 
Fig. 
-The fork-tailed katydid: Third-instar nymph. 
Three times natural size. (Original.) 
