INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



327 



THE AMERICAN SYRPHID FLY 



Syrphus americanm Wiedemann 



(Fig. 321) 



Description. — In general this species greatly resembles Syrphus 

 pyrastri (Linn.) in shape and color, though it is somewhat smaller. 

 The eyes are dark reddish-brown ; face, amber yellow with a dark band 

 in the middle extending. from 

 the base of the antennae to the 

 month; antennae, black, with 

 dorsal arista; thorax, iri- 

 descent green, covered with 

 fine, long hair; legs, amber 

 with bases dark; abdomen, 

 rich, shiny black with one 

 broken and three continuous 

 transverse yellow bands on the 

 dorsum. 



Distribution. —This sy rphid 

 is very common in all sections 

 of the State. 



Hosts. — The larva? feed 

 upon a great number of plant 

 lice, including the black peach 

 aphis, Aphis p&rsicce-niger 

 Smith, the melon aphis, Aph is 

 gossypii Glover, the green 

 apple aphis, Aphis pomi DeG., 

 the green citrus plant louse, 

 Macrosiphum citrifolii Ashm., 



Fig. 321. — The American syrphid fly, Syrphus 

 a mi ricanus Wied. Adults, enlarged three times. 

 . (Original) 



the destructive pea aphis, Macrosiphum destructor (Kalt. 

 black citrus plant louse, Toxoptera aurantm Koch. 



and the 



THE LARGE SYRPHID FLY 



Syrphus pyrastri (Linnaeus) 



[Catabomba pyrastri (Linnaeus)] 



[Lasiophthicus pyrastri (Linnaeus)] 



(Musca pyrastri Linnaeus) 



(Fig. 322) 



Description.— This is one of the larger syrphid flies, being nearly 

 | inch long. The compound eyes occupy most of the head and are dark 

 Indian-red or brown. The face is yellow and hairy, with median dark 

 line; the antenna? are black with long dorsal arista?; the thorax is iri- 

 descent dark blue or green and covered with long, fine hairs ; the scutel- 

 lum is the same color as the mesothorax ; the coxa? are dark ; the femora, 

 dark with tips light; the tibia?, amber or yellowish, slightly darker at 

 tips ; the taris, dusky ; the abdomen is velvety black with three pairs of 

 marginal curved transverse bands on the dorsum. These bands do 

 not come together in the middle, and so really form six broken bands. 

 In the females they are sometimes absent. The eggs are very small 

 and white. The larva?, when full-grown, are nearly f inch long and 

 vary from light green to light brown in color. The puparia are brown 



