30 



MISCELLANEOUS STUDIES 



26. Monellia caryella (Fitch) 



Figures 25, 67, 68 



Fitch, Insects N. Y., vol. 1, p. 163, 1855. Aphis (orig. desc. apt. vivL). 

 Fitch, Ins. N. Y., vol. 3, p. 448, 1856. Callipterus (first desc. ala. vivi.). 

 Davidson, Jour. Econ. Ent., vol. 7, p. 132, 1914 (list). 

 Davidson, U. S. Dept. Agr., Bull. 100, pp. 26-34, 1914 (desc. all forms). 



Records. Juglans calif ornica, J. Nigra, J. regia; San Jose, Walnut Creek 

 (Davidson) ; Stanford University, May to June, 1915. 



A more or less common species on both the native black walnut, 

 and the cultivated walnut in the San Francisco Bay region. This 

 species, while very similar to the preceding species, is probably the 

 more common of the two. The following table of differences is taken 

 from Davidson: 7 



Form 

 Alate viviparous female 



Callipterus caryae Monell Monellia caryella (Fitch) 



Pupa of viviparous 



female 

 Oviparous female 



Antennal joint III very 

 slightly thickened bas- 

 ally. 



Sensoria on antennal 



joint III occupying 



basal half or two- 

 thirds. 



Antennal joint VI and 



its spur or filament 



subequal, or VI less 

 than spur. 



Dusky knee spots often 

 present. 



Four longitudinal rows 

 of capitate spines. 



Smaller than viviparous 

 female. 



Four longitudinal rows 

 of cipitate spines. 



Antennal joint III quite 



noticeably thickened 

 * for its basal half. 



Sensoria on antennal 

 joint III occupying 

 basal third. 



Antennal joint VI one- 

 third as long again as 

 its spur or filament. 



Dusky knee spots absent. 



Six longitudinal rows of 

 capitate spines. 



Larger than viviparous 

 female. 



Six longitudinal rows of 

 capitate spines. 



This species is distinct from the preceding and according to Mor- 

 rison, who has examined eastern species, is structurally identical 

 except in the matter of the wings. He writes as follows : 



i Davidson, W. M., Walnut aphides in California, II. S. Dept. Agr., Bull. 100, 

 p. 28, 1914. 



