228 IOWA ACADEMY OF SCIENCES. 



abundant at Ames and doubtless occurs generally over the 

 state where willows are grown. 



Chionaspis ortholobis Comst. 



Taken by Mr. Newell on cottonwoodat Ames. It resembles 

 the preceding species but is shorter and broader. 



Chionaspis pinifolioe Fitch. 



This species, which is common on pine and spruce, and which 

 has been received from Davenport and has been collected at 

 other points along the Mississippi, has never been seen at Ames, 

 a fact which shows very strikingly the limited powers of 

 unaided distribution possessed by these insects and the great 

 importance of preventing the transportation of infested trees. 

 The scale is slender and white, closely fitting the narrow leaves 

 on which it occurs. 



Chionaspis furfurus Fitch. 



This is probably the most generally distributed and injurious 

 scale insect infesting orchards in Iowa at the present time. 

 The female scale is flattened, broadly oval or rounded, and the 

 exuviae at one end, and the male scale is n irrow, white, with 

 three carinse, one central and one at each side. The eggs 

 remain under the scale during the winter and hatch about the 

 first of June. 



Diaspis rosce. 



Specimens of this species were recieved from Muscatine in 

 1896, and a record made in the last volume of the Academy. 

 It has been received from Davenport also. It is not apparently 

 distributed over the state, but it thrives on a variety of plants 

 as well as the roses, and its dispersal should be prevented as 

 far as practicable. Like many other species it is often mis- 

 taken for perniciosus, but its white color, larger scale, and posi- 

 tion of the exuviae will enable a careful observer to distinguish 

 it by means of the scales alone. 



Diaspis cacti Comst. 



The various members of the cactus family are infested 

 with this species, and greenhouses may usually be depended 

 upon to furnish a supply. Mention of this species was made 

 in 1882, since which Professor Comstock has given it a tech- 

 nical description. 



