296 NEW YOEK STATE MUSEUM 



interlock, in which case every facility is afforded it for spreading 

 the infestation, — almost equal to that existing in nurseries where the 

 young trees are grown so closely together as to form compact masses. 



Carried by birds, etc. — It has been found that the young insect 

 may be distributed through the agency of other insects and of birds. 

 When abounding on a tree to the extent that much of the bark is 

 already occupied by the scales, they apparently show a disposition 

 to leave the tree and fasten upon any visiting insect or to the legs of 

 birds. If this is instinctive or in accordance with a purpose, they 

 will leave their hosts as soon as transported to a favorable place for 

 the establishment of a new colony. It is stated that several of the 

 young have been seen upon the wing-covers of a single lady-bird, — 

 that they are often found on ants, and that they show a preference 

 for insects of dark color. 



Distribution in Nursery Stock. — The ease with which many 

 of our most serious insect pests may be widely distributed through 

 sales of nursery stock, has been brought to notice so frequently in 

 recent years by studies made of the means by which injurious insects 

 have suddenly made their appearance in new localities, that our 

 economic entomologists have deemed it their duty from time to 

 time to warn fruit-growers of the danger to which they are exposed, 

 and to press upon them the great importance of a thorough inspec- 

 tion of all the nursery stock purchased by them. Each of the recent 

 occurrences of the San Jose scale in the Eastern States, has been 

 traced directly, or with a strong probability, to nursery infestation 

 as its source. Of course, the danger of such introduction is the 

 greater when the insect is so inconspicuous as is this scale, or when 

 it is entirely hidden within its burrows in the branches or trunk, as 

 in the case of the flat-headed pear tree borer, Agrilus sinuatus 

 Oliv., lately discovered in New Jersey orchards by Dr. Smith, 

 and by him traced to a New Jersey nursery which it was supposed 

 had imported it from Europe about ten years ago. 



Protection fkom Infested. Stock 



In view of this danger, the following suggestion made by Dr. 

 Smith {Entomological News, v, p. 311) is both timely and impor- 

 tant : " No farmer should set out a tree until he has examined it 

 closely and made certain that no scale-insects infest any portion of 



