Pomona College .Ioi-rnal ok Entomology 



507 



thirds, whil<' those of M. destructor nrc dusky only at the tips. Thr styles of .V. 

 cUrifolii nre the smallest, of M. rosae next in size (both of these are quite hairy) 

 while those of .V. drstruclor are mueh larger and nre nearly destitute of hairs. 

 The general appearanee of .V. rosae is also easily told by the rosy forms and liv thr 

 (lark legs, till- hlaek markings of the liiad. thorax, and ahdomrn. .N'either of the 





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Figure 194. Details of Macrosiphum citrifolii (a, b, g, h, m, n) : Macrosiphum 

 rosae (c, d, i, j. o. p) ; Macrosiphum destructor (e, f, k, 1, q, r) 



latter forms have these eharacters, exeept the darkenid areas on the ii'gs and 

 these are mueh fainter. 



Xatural enemies — Macrosiphum citrifolii .\shm. is very effeetually held in 

 cheek in California by the predaceous ladybird beetles, Coccinella californica Mann, 

 Hippodaviia convergens Guer. and Coccinella abdominalis Say and by the larvn- 

 of the .Syr])hid Flies Si^rphus amrricanus Wied., AUograpIn oUliifua .Say., and 

 I.asiophthicus pyrastri I,. 



I am indebted to Mr. John ,luiie Davis for his aid in the determination of 

 this species. 



