Missouri (Wright County): Eggs hatch early in May. Insect double brooded 

 according to a Mr. Wright (Riley). 



Olden, Mo., eggs hatched March 29, 1907; apple trees bloomed March 24 (Girault). 



Ozark region, Missouri, eggs hatch about April 25 to middle of May (Taylor). 



Illinois (Cook County): Eggs hatch about June 6, females reach full growth by 

 August 1, and oviposit August 12-28 (Riley). 



District of Columbia: Eggs hatch May 5-14 (Quaintance). 



July 4, eggs already deposited by most females and young crawling (Quaintance). 



Maryland: Eggs hatch early in May (Symons). 



Eggs of first brood hatch in May; eggs of second brood hatch last week of July to 

 first week of August (Johnson). 



College Park, many recently settled scales in evidence May 21 (S. W. Foster). 



Delaware: Eggs usually hatch in early May (Houghton). 



New Jersey: Eggs hatch during early June (Smith). 



Tennessee: In eastern Tennessee eggs hatch during first two weeks of April (Cham- 

 bliss). 



Eggs begin to hatch in April and those of the second brood along in July and August 

 (Bentley). 



This information as to the period of hatching of eggs in various 

 parts of the country is of importance as bearing on the time to spray 

 for the destruction of the young larvae. 



The female molts twice in the course of her growth, and in the 

 adult condition is entirely without legs or eyes, being nothing more 

 than a reproductive sack with her sucking mouth parts, through 

 which the food is taken, inserted in the tissues of the plant. The 

 adult male differs radically from the female in that it is provided 

 with antennae and one pair of wings, the second pair being present 

 in the form of club-shaped organs known as balancers or halteres. 

 During the process of metamorphosis the mouth parts entirely dis- 

 appear, and a second pair of rudimentary eyes assumes their place. 

 Being without any means of taking in food the male is naturally 

 very short lived, its only mission appearing to be the fertilization of 

 the female. 



MEANS OF DISTRIBUTION. 



Transportation by nursery stock, scions, or by grafting or budding 

 material is perhaps the only way this insect is carried from one section 

 of the country to another, and this in a large measure accounts for its 

 wide distribution. Locally it can be transferred from })lant to plant 

 only while in the young or crawling stage. The young are often seen 

 crawling on other insects, such as beetles, or upon the feet of birds, 

 and may in this way be carried some distance. Man and domestic 

 animals may also assist in their dissemination, and it is possible that 

 the winds blow them from plant to plant. 



FOOD PLANTS. 



The oyster-shell scale has a wide range of food ])lants, but is com- 

 monly found on apple, maple, horse-chestnut, poplar, willow, and 



[Cir. 121] 



