284 



THE WINGS OF PSYLLIDM 



A general view of the wings. — Figure 285 represents the tracheation of a 

 fore wing of a nymph of Psyllafloccosa. All of the principal tracheae except 

 the third anal are present and each arises separately from a transverse basal 



Fig. 285. — The tracheation of a fore wing of a nymph of 

 Psylla floccosa (After Patch). 



trachea. The subcostal trachea is not branched; the trachea that precedes 

 radius-one is well developed; the radial sector trachea is reduced to an 

 unbranched condition; the medial trachea is reduced to a two-branched 

 condition; the cubital trachea is typical; and the two anal tracheae are 

 unbranched. 



Fig. 286. — The tracheation of the wings of a freshly emerged 

 Psyllafloccosa (After Patch) 



The wings of a newly emerged adult show remarkable changes in the 

 tracheae, due to the reduction of some and to the coalescence of others 

 (Fig. 286). The tracheation in this stage corresponds very closely with 

 the definitive venation; the venation of the fore wing is represented by 

 Figure 287. 



