352 



JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 10 



16, and on V about 12 small circular sensoria arranged irregularly; joint VI having 

 only the usual "terminal" group. The oviparous female bears on her thickened hind 

 tibiae numerous small circular sensoria. 



The beak reaches to or a little beyond the third coxae. The stigma of the fore- 

 wings is rather elongate, the stigmal vein with a shallow basal curve thence con- 

 tinued ahnost in a straight line to the margin of the wing. The cornicles are imbri- 

 cated and club-shaped, constricted about basal third and again less markedly close 

 to the apex, their shape differing according to the form, those of the spring wingless 

 and oviparous female being less clubbed than in the other forms. The cauda is up- 

 turned in nature, about two-fifths as long as the cornicles, its apical portion quite 

 noticeably narrowed. 



A normal armature of hairs is found in all forms. 



Lateral tubercles are present on the pro-thorax in all forms; on abdominal segments 

 1 to 7 inclusive in the winged, on abdominal segments 1 and 7 only in the wingless 

 forms. 



Fig. 19. Rhopalosiphum nymphece Linn.: Fig. 1, stem mother, antenna; 2, stem 

 mother, cornicle; 3, spring migrant, head and antenna; 4, spring migrant, cornicle; 

 5, spring migrant, style (cauda); 6, summer apterous, head and antenna; 7, summer 

 apterous, antenna (apical segments) from smaller individual; 8, summer apterous, 

 cornicle; 9, summer apterous, style; 10, fall migrant, antenna apical segments; 11, 

 fall migrant, cornicle; 12, male, cornicle. All drawn to same scale: 



