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THE APPLE LEAF HOPPER 



The Antennae: The anlcnnae have frcjm three lo six cyhn- 

 (Irical joints. The two short sub-equal basal joints form the scape, the 

 others form the flagellum. In the early larval stage the flagellum is 

 two jointed ; during the larval development the proximal one of these 

 lengthens, and one or two additional joints are cut oft' from its distal 

 end. In some genera the first antennal joint is gibbous or notched 

 on its inner side ; this is especially noticeable in Mysiis and Plwrodoii. 



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Fifr. 94. n. Jird antennal joint of .1. opiilus. b. Same of cnl. marainrlUi. c. Scat- 

 tered marginal seiisoria. d. Marginal sensoria In a row. e. Marginal sensoriaina 

 pyramidal group, f. Sixth antennal joint of Mel. sal ids: 1, Circular sensoria. 2, 

 Terminal sensoria. :!, Marginal sensoria. 4, Terminal sense hair of the spur. 



The third joint is usually the longest. Some times [P. popitlicanlis 

 and populi-traiisz'crsus) it has a short tooth-like process on its outer 

 side near its base. The sixth joint is always modified by the develop- 

 ment of a spur, which arises as a finger-like outgrowth at its distal 

 end. In some of the higher genera the spur is as long as, or longer 

 than the third joint, and has been considered a separate joint by some 

 authors. In Pciiiphic/iis and related genera it is shorter than the basal 

 part of the sixth joint. 



The structures found on the antenna are hairs and sensoria. The 

 hairs may be classified as unmodified hairs and modified hairs. The 

 unmodified hairs found in Lachnus and Chaitoplwnis are long and 

 slender and do not difl^er from the ordinarv body hairs. The modified 

 hairs are of three varieties: Short spine-like hairs found generally in 

 the genus .Iphis: longer hairs with s])atulate tips, found typically in 



