THE CITRUS MEALY BUG 



309 



"The following table gives the actual counts of the numbers of eggs in 

 twenty egg-masses of Pseudococcus citri. They were collected on Salvia in a 

 greenhouse at Urbana, 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 suc- 

 cessive averages, there was little divergence from the final average." 



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

 i^eyond the tip of the abdomen in an entanglement of white cottony 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 meas- 

 ured, was 0.313 mm. in length by 0.164 mm. in width. 



PSEUDOCOCCUS ciTRi (Risso). 



In the orchards of Southern California conditions are verv favorable to 

 the growth of the mealy bugs, and never have I seen egg-masses in a green- 

 house that will begin to compare in size with those found in the combined 

 clusters on the citrus fruit. It is very conservative to say that the number 

 will reach 500 for some individuals. As yet I have never noticed any con- 

 siderable number of unfertile eggs. At least 99% of all eggs deposited will 

 batch and 95^^ of all the hatched young, under normal conditions, in the 

 orchards, will live to reproduce. In jars, without food all of fifty adults 

 produced eggs that hatched and 50% of the half-grown produced eggs that 

 hatched, but in tlie case of the latter the number of eggs per individual 

 equalled only about one-fourth that of the adult. 



