LIFE HISTORY OF CORIZUS LATERALIS SAY.* 



Bv J. C. Hambleton. 



This insect was first described by Say in 1825 under the name 

 Coreus lateralis. Again in 1852 Dallas described it as Rhopahts 

 pnnctipennis. Later, in 1859, Signoret in his "Monograph of 

 the Genus Corizus" acknowledged both species, having been 

 guided largely by color characters. 



There are in all twelve known species of the genus in North 

 America,! this being one of the most widely distributed, though 

 apparently confined to the United States. It has always been 

 a source of trouble to collectors because of its extreme variability 

 in color. 



Up to the present, little has been known and nothing pub- 

 lished in regard to the life history or habits of any of them. 

 Prof. Herbert Osbom found nymphal forms of hyalinus Fab. a 

 few years since on a species of Euphorbia, but has published no 

 complete description of its stages, t 



Lateralis was found this past summer in great abundance in 

 the neighborhood of Columbus, Ohio, wherever its host plant was 

 found. This is Polygomim pennsylvanicum a native annual that 

 is quite generally distributed over the whole of the United States. 

 Adult insects could always be taken also on colonies of Poly- 

 gomim persicaria, a species introduced from Europe, and also 

 widely distributed, however neither eggs nor young were found 

 upon it. Several broods of young were reared to maturity on 

 persicaria in the laboratory and no difference could be observed 

 between them and those reared on pennsylvanicum where 

 the eggs w^ere deposited. The adult forms fed freely upon persi- 

 caria in captivity and apparently do so in the field since they could 

 always be taken on colonies of this plant, but as aforesaid, dili- 

 gent search failed to reveal either eggs or young. This is evident- 

 ly a case of partial adaptation that has taken place since the ad- 

 vent of the plant to this country. The question may be asked, 

 \\'hy does the female not deposit her eggs on this plant as well 

 as on the other when she herself feeds upon it and when her 

 young will thrive upon it? 



*Read at the nieeting of the Ohio Academy of Science, at Delaware, O.. 

 Nov. 26th. 1909. 



t Ann. Ent. Soc. of America, Vol. I, p. 133. 



I Bull. No. 46, U. S. Dept. of Kg. Div. of Entom. p. 89. 



272 



