March, '08] ENTOMOLOGICAL NEWS. 131 



Chaitophorus Testudinatus in America. 



BY O. W. OESTLUND, University, Minn. 



In the December number of the NEWS there appeared an in- 

 teresting article on the dimorph of Chaitophorus negundinis 

 Thos., as observed in Colorado by Mr. Bragg. The follow- 

 ing notes and corrections may therefore be timely as attention 

 has now been called to this peculiar form in America. I found 

 the same quite abundant on the maples in Minneapolis in 1897, 

 and have since observed it at various places in Minnesota. 



Mr. Bragg, it appears, is unaware of Kessler's* paper on the 

 same dimorph, the most complete on the subject. The dimorph 

 \vas first discovered and described by Thorntonf as Phyl- 

 loplionis testudinatus, and by him considered to belong to some 

 undescribed aphid. Balbiani and Signoretj: later proved its 

 connection with the Chaitophorus on the maple, since consid- 

 ered as CliaitopJwrns accris (L.) Koch, 1854. They also came 

 to the conclusion that the dimorph, after continuing in an un- 

 changed condition for months, at last perishes and comes to 

 nought. Kessler, in the above mentioned article, showed that 

 three distinct species had been included under ChaitopJwnis 

 accris by authors, quite similar in general appearance but very 

 distinct as to life-history. 



A green variety Kessler assigns to the original Chaitophorus 

 aceris (L.) Koch., 1854; a brown variety he ascribes to Chui- 

 toplwnis testudinatus (Thorn.) Kessl., 1886; the third variety 

 is described as new under the name ChaitopJwnis lyropictus 

 Kessl., 1886. The first two have a summer generation that re- 

 main as larva in an unchanged condition for three months or 

 more, after which they resume active life and pass through the 

 customary moults. As adults they proved to be the sexupara 

 producing the true sexes : the apterous females and winged 

 males. The dimorph of the first differs from the second in 

 wanting the flabelke and in the body not being flattened. 



*Kessler, Nova Acta Leop.-Carol. Akad., Vol. 51, pp. 151-178. 1886. 

 t Thornton, Trans. Micr. Soc. London, Vol. 3. 1852. 

 $ Balbiani et Signoret, Comptes rendus Acad. Sci., Vol. 14. 



