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JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 8 



the bark and so numerous were they that the roots appeared to be 

 covered with a thin layer of cottonwool. All examinations failed to 

 disclose nymphs or winged forms. Pergande states that some of the 

 eggs deposited by the apterous adults were sexual. I failed to find 

 any sexual lice and it is hkely that in California the asexual generations 

 proceed to reproduce throughout the winter as is the case with many 

 other species. Dates of observation were November 6, 1913, Feb- 

 ruary 3, 1914, October 15, 1914. On all these dates the colonies 

 comprised eggs and lice in all instars. Collected at Walnut Creek, 

 California. 



Phylloxera popularia Pergande 



Phylloxera popularia Pergande; Pergande, North American Phylloxerinae Affecting 

 Hicoria (Carya) and Other Trees. Trans. Davenport Acad. Sci., IX. 



Infests the limbs and twigs of Populus trichocarpa T. & G. and P. 

 fremontii Wg.ts. The individuals are covered with a white cottony 

 substance and are usually to be found in cracks or clefts in the bark 

 where they obtain food from the inner layers. They also invade old 

 galls of Thecahius populicaulis Fitch. Specimens collected April 20 

 and May 4, 1914, at Walnut Creek, Cahfornia 



Thecahius populicaulis Fitch 

 Pemphigus populicaulis Fitch; Fitch, Kept. Ins. N. Y., Y, 1859. 



In the latitude of San Francisco I have observed the sexuparse under 

 poplar bark (Populus fremontii AVats.) in late winter and spring. Some 

 were found alive and depositing sexes as late as May 12. 



The sexes appear to cast four molts, all in rapid succession, and im- 

 mediately after the final molt they copulate and the single egg is 

 laid in a crevice in the bark, on trunk or larger limbs or any dead plant 

 matter that may be touching the tree. The female is pale orange, 

 beakless, and when gravid measures about .86 mm. x .38 mm. and after 

 the egg has been laid but .44 mm. x .36 mm. The male is darker and 

 narrower, also beakless, and measures about .60 mm. x .25 mm. The 

 females are much more abundant than the males. After the female 

 has deposited the egg she remains active for a short period, much 

 shrunken and brown. A day before the deposition of the egg, cottony 

 filaments are excreted by the female and she contrives to cover the 

 egg with these. Incubation in May takes about two weeks. The 

 egg at first is yellowish-green, but before it hatches the color be- 

 comes apple green. The egg is about half a millimeter in length and 

 about half as wide. The fundatrix after hatching is apple green with 

 black transverse bars on the dorsum. For a few days (in April and 

 May) it remains close by the empty egg-shell under the protection of 

 the bark of the tree. Later it ascends the tree and seeks a young leaf 



