44 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 9 



we transferred P. Carolina from horse nettle to tomato they unanimously 

 chanfjed from gi'cen to l)lack at the first moult and we felt quite sat- 

 isfied that this change was due to the change of food hut just at that 

 time we hai:)pened to bring in the same species from our tobacco and 

 placed them on growing tobacco in our cages, when they just as 

 prompth' and just as unanimously moulted to black. 



Another insect which we took on several occasions from this weed was 

 a very peculiar elongate Lyga^id bug, Ischyiodemus f alliens Say, this 

 with two leaf-rollers are still under study. One of the leaf-rollers 

 transferred to tomato passed through its maturation and is now in 

 pupa. 



President Glenn W. Herrick: I would like to ask ]\Ir. Somes 

 if these insects were found living on these weeds. 



Mr. M. p. Somes: The study is based on twelve or fifteen insects 

 found on this weed and was undertaken because of its close botanical 

 relationship to so many important cultivated plants. 



President Glenn W. Herrick: It seems to me that studies of 

 this kind are very important and that more information on our com- 

 mon native weeds might be very useful. The next paper will be read 

 by Miss Edith M. Patch. 



CONCERNING PROBLEMS IN APHID ECOLOGY^ 



By Edith M. Patch 



It is apparent enough that in ecological work with an aphid, the 

 fact of first importance to be ascertained is whether a given species 

 is migratory, for, if it have two types of host plants, the problems that 

 concern its life cycle are doubled, though the economic situation 

 may be simplified by virtue of a greater choice in methods of control. 



Something of the import of this was recognized b}^ Walker, who, 

 in 1848,^ published ''Remarks on the Migrations of Aphides," in 

 which he records the alternation of food plants of several species with 

 certain economic suggestions. This discussion included the migration 

 of the hop aphid from the plum, Siphocoryne caprew alternating 

 between the willow and umbelliferous plants and a few other leaf- 

 feeding species — the change in food plants not in any case involving 

 any startling change in the habits of the insects concerned. 



1 Papers from the Maine Agricultural Experiment Station: Entomology No. 84. 

 - 1848. The Annals and Magazine of Natural History, Vol. I. Second Series, 

 pp. 372-373. 



