— 6 — 

 Aspidiotus ancylus. 



Originally described from specimens taken at Davenport, 

 this species has attracted little attention until within a few 

 years, when the close resemblance of its scale to that of the 

 San Jose has made it well known It is very small and usually 

 too few in numbers and scattered to attract attention. Mr. 

 Newell has recently collected it at Ames from maple, cherry, 

 plum, and birch, and it evidently has a general distribution in 

 the state. 



Aspidiotus ancylus var serratus Newell and Cockerell n var. 



This occurs very sparsely on native willows The scale of the female is 

 small, less than one mm in diameter, and dark grayish, the same color as 

 the bark of the host. 



This form differs materially from ancylus proper in the following char- 

 acters: Median lobes more truncate and minutely serrate at end. The 

 glandular thickenings of the first interlobular interval are about equal. 



A very small and obscure variety that is difficult to detect, but which is 

 of little economic importance. 



Aspidiotus forbesi Johns 



This species has been collected at Des Moines and at Ames 

 and doubtless has a general distribution through the state, 

 although its minute size and usually scant numbers seldom 

 bring it to notice. It is one of the most closely related to the 

 San Jose scale, and without close microscopic study is sepa- 

 rated only with great difficulty. It occurs on cherry, apple, 

 crab, ash, and a number of other plants. 



Aspidiotus osborni Newell and Cockerell n sp. 



Scale of female small, oval, 1 to 1.25 mm. in length by i to f mm. in 

 breadth, irregularly margined, dark, spotted minutely, and of a general 

 scurfy appearance; exuvia dark brown, submarginal, small; scale of imma- 

 ture female more elongate and frequently curved to one side: ventral scale 

 a mere white film. 



Body of female circular, last segment yellow. Ultimate ventral seg- 

 ment: median lobes well developed, close together, produced, compara- 

 tively long and narrow, erect, scarcely or not at all notched on the inner 

 side near end, but well notched about half way down on the outer side, 

 ends sometimes minutely serrate; second and third lobes wanting; two 

 incisions present, the glandular thickenings of the first incision long, 

 about equal, well apart, outer straight, the inner nearly so, glandular 

 thick^^nings of the outer incision like those of the first, a small thickened 

 pciifi<;ss just laterad of apex of first incision; plates spine-like, about equal 

 in length to median lobe, often angularly curved near apex, situated, one 



