77 



fouiid it on the same food plant in Ohio. The grape scale, Aspidiotus 

 iivcv, is very often found in Illinois, but is not a serious pest so far as I 

 know. 



The oyster- shell bark-louse (Mytilaspis pomorum) is common through- 

 out Illinois, and is, in my opinion, the cause of far greater injury to 

 apple trees in that State than has been attributed to it. I believe it 

 is double-brooded as far north as Springfield, 111. The eggs of the first 

 brood hatch early in May at Champaign, and I believe a second brood 

 appears in August. I found this scale on rose (Baltimore belle) at 

 Relay Station, Maryland, this season, from which I bred the adult male 

 insects August 8. 



The scurfy bark-louse (Chionaspis furfnrus) is also very injurious to 

 apples in Illinois. I have shown by a series of experiments, conducted 

 a year ago, that this species is two-brooded. At Champaign the young 

 of the first brood appear about the 1st of May, and the female begins 

 to deposit eggs for the second brood usually the first week in July. 

 The young of this brood begin to appear about July 10, and the adult 

 males are abundant usually from the 10th to the middle of August. 



I have found several other species of Chionaspis on shade trees in 

 Illinois, but will mention only three of them in this place. The willow 

 scale (Chionaspis salicis) is very common on willow. The pine scale 

 ( Chionaspis pinifolice) is also very destructive. Several large and beau- 

 tiful pines on the campus of the University of Illinois have been killed 

 this season, and two were dug up and burned last year. The scale is 

 double-brooded in that region, the first brood appearing usually the 

 first week in May and the second the first week in July. Another spe- 

 cies of this genus, which I have described as Chionaspis americana, is 

 found on white elm ( Ulmus americana) throughout Illinois. Mr. E. H. 

 Pettit has also sent me the same species on elm from Minnesota. It is 

 veiy destructive to elms planted for shade and ornamental purposes. 

 I have also found it upon virgin timber, and believe that it is a native 

 American insect. The female scale is yellowish brown at first, but 

 becomes lighter, nearly white, with age and exi>osure. The male scale 

 is pure white, aud characteristic of the genus. The eggs are purplish. 

 There are two broods, the first appearing about the 1st of May aud 

 the second early in July. The male is peculiar in that there are two 

 forms — one with well-developed wings and the other with mere stubs. 

 The attack is confined to the trunk, branches, and twigs. The male 

 scales often cluster on the underside of the leaves; an occasional one, 

 however, may be found on the upper surface. 



The rose scale (Diaspis rosce) has been very destructive to raspberry 

 and blackberry in Illinois for several years. It is also common on rose. 

 The peach lecanium (Lecaniurn persicce) was reported to mebythe Prairie 

 Farmer from one locality in Madison County, 111. The attack was con- 

 fined to a single tree, which was cleared by close pruning and a 1 borough 

 washing with soap. 1 bred au adult male of this species from material 

 from this tree April 24, 1 805. 



