1912] Eiciny and Webster — 3Iites Associated with the Oyster-Shell Scale 127 



made to his observations, together with some additional notes 

 made in Iowa. 



In France, Lignieres found the eggs of Hemisarcoptes during 

 practically the whole year. They were abundant beginning in 

 April, reaching the maximum about the middle of May. Then 

 there was a decrease until the latter part of July, following an 

 increase, then again a decrease, reaching the minimum in Novem- 

 ber, December and January. In February and March there was 

 a slight increase. 



The Iowa notes show a similar condition here. Under some 

 scales taken March 24, in Northern Iowa, the eggs and mites of 

 this species were abundant when examined March 29. Again 

 these mite eggs were found abundant under scales examined April 

 14 and May 4, having been taken at places in northern Iowa a 

 few days previous to their examination. In each case the eggs 

 were common and the mites quite active. 



Again, later in the year, Hemisar copies eggs were abundant 

 around iVmes, this being noted August 19 (1910), and as late as 

 Octobers (1911). 



The eggs of this species we found to be deposited among the 

 fresh eggs of the oyster-shell scale. They are a little less than 

 half as long as the eggs of the scale insect, more shiny and less 

 granular in appearance. They are white, broad oval, .10 mm. 

 long, .07 mm. broad. 



Lignieres observed these eggs in his work in France, and he gave 

 a description of them, together with some notes on their period of 

 incubation. From five eggs which were deposited at one time or 

 another in the spring, he found that about twenty days were re- 

 quired for them to hatch. We have but a single observation to 

 add to this. One of the eggs that was obtained from among fresh 

 oyster-shell scale eggs at Ames, August 19, hatched on August 31. 

 This egg was found with two others and the female, so it proba- 

 bly had not been deposited long. It is possibjie that the egg stage 

 is about twelve or fifteen days in midsummer, somewhat less than 

 in the spring, although we have no exact data to show this. 



The larvae of this species are very simi,lar to the adults, except 

 that they are hexapod, not octopod, and are hardly as active. 



That lignieres fully appreciated the value of this important 

 mite is shown by the following extract from his paper. 



