378 STATE HORTICULTURAL SOCTETY 



We have frequently found this species in the nursery, usually on young 

 plum trees, but in no instance were the scales in sufficient numbers to 

 injure the trees to an appreciable extent. 



According to Prof. T. D. A. Cockerell,* this scale is found upon ash, 

 maple, beach, linden, oak, osage orange, peach, hackberry, bladder nut 

 and water locust. 



PLANT LICE. 



The nature of these insects in general need not be enlarged upon here, 

 as the principal points in their development will be touched upon in 

 another bulletin. These insects were unusually abundant last year in 

 both nurseries and orchards. One of the species Hi/dloptcrus pnini, 

 which was abundant on the plum last season is shown at Plate VI, fig. 

 5. This species was also very abundant in some of the nurseries exam- 

 ined last season, but will be discussed more in detail in the bulletin 

 above referred to. 



THE WOOLLY LOUSE OF THE APPLE. 



Schizoneura lanirjera Hausm. 



The writer has found this species more common in New York nurseries 

 than any of the other injurious insects. As a rule apple trees were the 

 worst infested, but blocks of pears or quince trees growing next to blocks 

 of infested apples, were also usually infested. 



The life history and habits of this insect, together with its importance 

 as a nursery stock pest, are discussed by the writer in the Annual Report 

 of the station for 1895, pages 570-577, and hence it will be unnecessary 

 to discuss these points in detail here. It may be stated, however, that 

 in some sections of the state this species of woolly aphis is doing very 

 serious injury every year, both in the nurseries and young orchards. 

 The insect and its work are illustrated at Plate V, tigs. 1 to 5. All of 

 the photographs for this plate were made from an infested apple tree 

 taken from a nursery at Geneva. The insect works on both roots and 

 branches. Those infesting the former are referred to as the root inhabit- 

 ing form and those on the branches as the aerial form. The injury to the 

 roots caused by the lice is shown at Fig. o. The larger roots are more 

 or less deformed and are covered with galls. A nearer view of some of 

 the galls is shown at Fig. 4. Fig. 1 shows the appearance of a badly 

 infested twig. The lice collect on the under sides of the limbs and 

 twigs and secrete a bluish white cottony substance which completely 

 covers them. If these lice are removed it will be found that they have 

 formed numerous galls and pits on the bark. At Fig. 2 one of these galls 

 and some of the lice, with most of the cottony substance removed, are 

 shown enlarged to about four times natural size. 



The lice are distributed in the nui'sery or orchard by means of the 

 migrating females, but they are distributed over the country by means 

 of infested nursery stock. Many trees with infested roots are shipped, 

 but the lice are frequently found in the scars along the trunks of the 



*U. S. Dept. Agr. Div. Ent. Bui. No. 6, technical series, p. 20. 



