1919] 



ECONOMIC ZOOLOGY — ENTOMOLOGY. 



Gl 



cauliflower, and broccoli (/>'. olerocea botrytis), Brussels sprouts < n. oleracea 

 hi inmifcra), rape ( H. napus), Coronopus didymus, Lepidium oirgintcum, and 

 Roripa sp. . . . Winged migrants (fundatrlgenla) of the species of Pemphigus 

 under consideration bave been found at the roots of cabbage, turnip, Brussels 

 sprouts, rapes 0. didymus, and Roripa sp. it Is quite possible thai Further obser- 

 vations will disclose the fact that the species occurs also at the roots of plants 

 not belonging to the family Cruclferee." 

 Winged females have been found in the soil as early as December 12 and as 



late as April !). Six was the greatest number Of sezed individuals to which a 

 winged migrant from crucifers was observed to give birth. Only a single egg is 



deposited by the true sex. 



The seasonal history of this aphid at Baton Rouge is illustrated by the fol- 

 lowing diagram : 



Seasonal history of P. populi-transversus at Baton Rouge, La. 



Jan. 



Feb. 



Mar. 



Apr. 



May. 



June. 



July. 



Aug. 



Sept. 



Oct. 



Winged female migrants 

 in galls. 



Nov. 



Colonies (stem mothers and their progeny) 

 in gala ou leaf petioles of poplar. 



Stem mothers 

 (outside galls) on poplar. 



Fggs. I 



ou poplar! 



True sexes. 



on poplar. 



Winged female mig rants, 

 (from crueller roots) on poplar. 



Above ground. 



Winged f emale migrants (from ga lls 

 on poplar; on erueifer lea\ i 



Dec. 



Above ground. 



I I 



Below ground. 



Jan. 



Feb. 



Mar. 



winged female mi 

 I grants in soil. I 



i i i 



Colonies (progeny of winged female mi grants 



from galls on pcplar) on erueifer roots. 



I I 



Below ground. 



Apr. 



May. 



June. 



Julv. 



Aug. 



Sept. 



Oct. 



Nov. 



Dec. 



Descriptions of Stages of P. populi-transversus and Its Gall, by C. P. Gillette 

 (pp. 589-592), and a list of 23 references to the literature cited are appended*. 



New pests and their natural enemies: Three new Argentine scales and their 

 parasites, P. Caridk Massini and J. Bb&thes (An. Soc. Rural Argentina, 52 

 (1918), Xo. S, pp. 148-158, pis. 8, figs. 10).— The three new Argentine scales, 

 Pulvinaria piatensis, I', flavescens, and P. ininutu. are described, together with 

 five hymenopterous parasites reared from them which represent two new 

 genera (Onophilus and Pseudaphelinus) and five new forms. 



Destruction of nits of the clothes louse by solutions of cresol soap emul- 

 sion and lysol, A. W. Bacot and L. Lloyd (Brit. Mid. Jour.. 2fo. 8991 (1918), 

 pp. -J79, J/SO). — The authors have found that lysol (crude phenol and soft soap 

 emulsion) solutions are decidedly more effective than the cresol soap emulsion 



