BULLETIN" 256, U. S. DEPARTMENT OP AGRICULTURE. 



Fig. 6.— The fork-tailed katydid: Second- 

 instar nymph. Somewhat more than 

 twice enlarged. (Original.) 



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 

 equilaterally 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 hi 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. Wing-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 in the hind wings and a few 



Fig. 7.— The fork-tailed katydid: Third-instar nymph. 

 Three times natural size. (Original.) 



