98 THE CANADIAN ENTOMOLOGIST 



Bases of the four anterior coxae, the four anterior femora posteriorly 

 and the posterior femora except apices; wings hyaline, venation 

 brownish. v- 



Male. — Length 2 mm. Sculpture as in the female. Black; 

 palpi, face below a line slightly above the bases of the antennae, 

 posterior orbits to the height of the yellow on the face, scape and 

 pedicel beneath, spot on the pronotum laterally, spots on the 

 abdomen laterally on tergites three and four, yellow; legs yellow, 

 coloured as in the female except tibice and tarsi are slightly brownish. 



Crescent City, California. Described from four females, one, 

 type, and four males, one allotype, recorded under Bureau of 

 Entomology Number Hopk. U. S. 10850J. Material collected by 

 P. D. Sergent and reared by J. M. Miller in April and May, 1914, 

 from seeds of Picea sitchensis. 



Type.— Cat. No. 19066, U. S. N. M. 



THE RATE OF HATCH OF SCALE INSECT EGGS. 



BY C. W. WOODWORTH, UNIVERSITY OF CALIFORNIA, BERKELEY, CAL. 



Scale insects, particularly those of the sub-family Lecaninae, 

 are among the most prolific insects, and evidently the normal 

 death rate will be in the neighbourhood of 99.9%, since at least 

 a thousand eggs is the normal reproduction and males are very 

 rare in the two commonest species. 



At what point in the life history the greater part of this re- 

 duction in numbers occurs has never been investigated fully, 

 but we have now rather extensive data upon the rate of death 

 before hatching. 



A very large series of experiments was carried on last spring 

 upon the effect of cyanide gas, and half the eggs from each insect 

 experimented with were kept untreated as a check. Two hundred 

 lots of a hundred insects each were in these experiments, and, 

 estimating 500 untreated eggs in each, the data below gives the 

 rate of hatch determined from observations on about 10,000,000 

 eggs. 



These studies covered five species and twelve localities, 

 Ontario and Santa Barbara in the South, and Anderson, about 

 500 miles to the north, give more than the average hatch, and the 



March, 1915 



