68 MISCELLANEOUS STUDIES 



This reddish-colored Macrosiphum is distributed abundantly 

 through the San Francisco Bay region and southern California on 

 various Compositae. In one case the author found it doing consider- 

 able damage to chrysanthemums by stunting and distorting the buds. 

 Once he found it infesting the tender leaves and stalks of willow. 

 The author reared specimens of Diarctns rapae Curt, from an infesta- 

 tion of this species taken on willow. 



77a. Macrosiphum rudbeckiae (Fitch) var. madia n.var. 



Figures 153, 154 



In September, 1915, the author found a species of Macrosiphum 

 infesting the heads of tarweed (Madia sativa) on the campus of the 

 University of California, Berkeley. Specimens of Praon simulans 

 Prao. were reared from this collection. Mounted specimens are almost 

 identical with M. rudbeckiae (Fitch), but in life they differ in the 

 coloration. Because of this it has been thought best to describe it 

 herewith as a color variety of M. rudbeckiae, naming the variety. 

 madia, after its host plant. 



Host: Madia sativa. Date: September 12, 1915. 



Locality: Berkeley, California. Collection number: AFS 70-15. 



Alate viviparous female. Prevailing color: dark-green, slightly 

 pruinose. Head brownish (fuscous), about as long as broad, with 

 distinct antennal tubercles. Antennae black, except I and II and the 

 base of III, which are concolorous with the head. The spur is slightly 

 longer than III ; IV is next in length, followed by V, VI, and I, which 

 are subequal, and II, which is the shortest segment. The spur is about 

 six times as long as the base of VI. The usual primary sensoria are 

 present on V and VI, and the usual accessory sensoria on VI. IV is 

 without sensoria, III has 25-35 irregularly arranged, various-sized 

 secondary sensoria placed along the whole length of the segment 

 (fig. 154). The thorax is fuscous; the prothorax with rather distinct 

 lateral tubercles. The beak is slightly dusky with the apical one-third 

 black, reaching to the second coxae. The abdomen is greenish with a 

 slight pulverulence, making it appear pruinose. The cornicles are 

 long, slightly tapering, black except the basal one-third, which is 

 concolorous with the abdomen, apical one-fifth reticulate (fig. 153). 

 The cauda is long and pointed, pale (slightly reddish?), about one- 

 half as long as the cornicles. The legs are black except the basal half 

 of the femora and the coxae, which are greenish. The wings and 

 venation are normal. 



