KATYDIDS INJURIOUS TO ORANGES IN CALIFORNIA. 



9 



The fork-tailed katydid: Fourth-instar nymph. About three times 

 natural size. (Original.) 



are faintly visible in the forewings. The pronotum covers about one- 

 half the dorsum of the rnesothorax. The sexes can be distinguished 

 in this stage by the appearance of the external genitalia. Just after 

 the third molt 

 the nymph is 

 about two-fifths 

 inch long. 



Fifth instar (fig. 

 9). — Measure- 

 ments: Length 

 of body, 12.5 

 mm.; pronotum, 

 3 . 1 mm . ; pos- 

 terior femur, 13 

 mm . ; antenna, 

 26 mm. In this 

 instar the posi- 

 tion occupied by 



the wing-pads is different from that in any of the earlier instars. 

 They now He partly over the abdomen in a tectiform position, this 

 change being brought about by the previously outwardly exposed 

 sides being brought out, upward, and in leaving the inner sides 

 exposed roof-shape above the body. The tips of the posterior 

 wing-pads now reach to the hind margin of the second abdominal 

 segment; wing-pads similar in shape, in position relative to the body, 



and in venation to 

 the adult wings. 

 Pronotum complete- 

 ly covering the dor- 

 sum of the rneso- 

 thorax. The young 

 of this instar are 

 about one-half inch 

 long shortly after 

 the molt. 



Sixth instar (fig. 

 1 0) . — Measurements : 

 Length of body, 16 

 mm.; pronotum, 4.5 

 mm.; posterior fe- 

 mur, 18.5 mm.; an- 

 tenna, 3.9 mm. In 

 tin-, instar the nymphs resemble adults in almost every particular 

 except the smaller size of the wings. Just after molting the wings 



extend rooflike over the abdomen to the ninth segment, the dorsal 

 93417° Bull. 266 16- —2 



. 



Fig. o.— The fork-tailed katydid: Fifth-taster nymph. 

 time natural size, (Original ,) 



About tlin-i 



