New York Agricultural Experiment Station. 459 



in the form of two small, rounded projections on the ventral side 

 of both the eighth and ninth abdominal segments. They are close 

 together and are most pronounced at the posterior margins of the 

 segments. 



Third instar (Plate XXVIII, fig. 3) : The pronotum is a trifle longer 

 than broad; marginal bristles very numerous. The metanotum is 

 about one and one-half times as long as the mesonotum. The sides 



of both bear rudi- 

 mentary wing pads 

 reaching nearly to the 

 middle coxae. (Fig. 26, 

 c.) The cerci are 

 noticeably longer, about 

 five times as long as 

 width of base. The 

 antennal segments are 

 relatively shorter than 

 in preceding stages and 

 the normal number of 

 segments is increased 

 to nearly one hundred. 

 The anlage of the 

 ovipositor consists of 

 four backward-pointing 

 papillae. The front pair 

 is smaller and lies in 

 contact with the lower 

 surface of the hind 

 pair. 



Fourth instar (Plate XXVIII, fig. 4): The wing pads, in com- 

 parison with earlier instars, are greatly increased in size and instead 

 of projecting downward are folded back over the meso- and meta- 

 notum. (Fig. 26, d.) The bases of the first pair are covered by the hind 

 margin of the pronotum and their tips reach the first abdominal 

 segment. The second wing pad covers the lower part of the first 

 and reaches to the middle of the second abdominal segment. The 

 four components of the ovipositor are longer than before and form 

 a compact body, extending a trifle beyond the tip of the abdomen. 

 The sterna of the eighth and ninth segments are reduced and almost 



Fig. 26. — Thoracic Segments of Nymphs. 



