A SYNOPSIS OF THE APHIDIDAE 131 



species is similar to species of Rhopalosiphum, particularly in the 

 shape of the cornicles and cauda, but owing to the absence of antennal 

 tubercles it falls into the tribe Aphidini instead of Macrosiphini. 

 Hence Walker's genus Liosomaphis is maintained for this species. 



33. Genus Siphocoryne Passerini 



Passerini, Gli Afidi, 1860. Type Aphis pastinacae Linn, (xylostei Schrank). 



There has been much diversity of opinion concerning this genus, 

 some aphidologists considering it as Siphocoryne Passerini, some as 

 Hyadaphis Kirkaldy, and some as a synonym of Rhopalosiphum Koch. 

 This last is incorrect as this is most certainly not a Macrosiphini for 

 the antennal tubercles are lacking. In 1904 Kirkaldy proposed the 

 name Hyadaphis to replace Siphocoryne, but in the author's opinion 

 this is uncalled for, so he maintains the original name, Siphocoryne 

 Passerini. 



There have been reported from various parts of California eight 

 species of Siphocoryne as follows: capreae (Fabr.), conii (Dvdn.), 

 foeniculi (Schrank), nymphaeae (Linn.), pastinacae (Linn.), salicis 

 (Monell), umbellulariae (Dvdn.), and xylostei (Schrank). There 

 are, however, really but three species; capreae (Fabr.), nymphaeae 

 (Linn.) and pastinacae (Linn.). According to Gillette, 20 S. salicis 

 Monell is a synonym of S. capreae (Fabr.), and xylostei (Schr.) of 

 pastinacae (Linn.). Davidson 21 states that S. conii (Dvdn.) is a 

 synonym of xylostei ( Schr. ) , and therefore it is the same as pastinacae 

 (Linn.). Morrison writes that the specimens Davidson called S. foeni- 

 culi (Schr.) are capreae (Fabr.), and those he described as Hyadaphis 

 umbellulariae n.sp. are S. pastinacae (Linn.). These two species, 

 pastinacae (Linn.) and capreae (Fabr.), have been greatly confused 

 but Gillette 22 has worked out their synonymy quite satisfactorily. The 

 following key for distinguishing them is from his paper. 



Joints 4, 5, 6, and antennal spur subequal, the spur usually distinctly the 

 longest, cornicles fully three-fourths as long as third joint of the antenna, a small 

 tubercle on the alate form and a large one on the apterous individuals always 

 present capreae 



20 Gillette, C. P., Two Rhopalosiphum species and Aphis pulverulens n.sp., 

 Jour. Econ. Ent., vol. 4, pp. 320-325, 1911. 



21 Davidson, W. M., Plant louse notes from California, Jour. Econ. Ent., vol. 7, 

 p. 133, 1914. 



22 Gillette, C. P., Two Rhopalosiphum species and Aphis pulverulens n.sp., 

 Jour. Econ. Ent., vol. 4, pp. 320-325, 1911. 



