Oct., '08] 



ENTOMOLOGICAL NEWS. 



383 



Standards of the number of eggs laid by Insects .VII* 



Being averages obtained by actual count of the combined eggs from 

 twenty (20) depositions or masses. 



BY JOHN J. DAVIS, Office of State Entomologist, Urbana, 111. 



The following table gives the actual counts of the numbers 

 of eggs in twenty egg-masses of Pseudotoccus citri. They were 

 collected on Sali'ia in a greenhouse at Urbatia, Illinois, March, 

 1907. The table shows a wide range in the numbers per egg- 

 mass, namely : 147 to 414 ; but, as will be seen in the succes- 

 sive averages, there was little divergence from the final average. 



The "corn" or clay-colored eggs are laid in a mass beneath 

 and spreading beyond, the tip of the abdomen in an entangle- 

 ment of white cotton}- secretion. They are elliptical-oval, 

 somewhat glossy, and measure 0.309 to 0.326 mm. in length, 

 and 0.146 to 0.180 mm. in width. The average, from 15 eggs 

 measured, was .0313 mm. in length by 0.164 mm - in width. 



8. PSEUDOCOCCUS CITRI (Risso). 



*"This series will hereafter contain independent articles bv myself and Mr. J J. 

 Davis, who has consented to include such studies along this line that he may make from 

 time to time, in order to bring them together under the same general heading for the 

 convenience of bibliographers and others. No. VII is Mr. Davis' first of this series. For 

 similar studies bv Mr. Davis on Sainia cecropia Linnaeus, J J iili-inafia iiinui,-in^ili^ 

 Kathvon and Culex pipiens Linnaeus, see EN r. NKWS, 1906, pp. ^68-369. 



For the first six of this series, see KNT. NKWS, IQOI, p. 305; 1904, pp. 2-3; 1905, p. 167 ; 

 1906, p. 6; 1907, p. 89, and 1908, p. 4. A. A. GIRAULT." 



