9 



the specific distinctness of the so-called variety. Riley (Ann. Bept. 

 U. S. Dept. Agr., 1881- , p. 352) gives as the food plants of this species: 

 Maple, grapevine, Osage orange, oak, linden, elm, hack berry,' sycamore, 

 rose, currant, and Euonymus, and Putnam adds locust, sumach, wild 

 grape, box-elder, beech, and willow. Careful studies of the forms occur- 

 ring on all of these plants are, however, liable to indicate specific 

 differences. 



Habits and life history. — This species is a large naked scale insect, 

 which is rendered conspicuous during the summer by a large white 

 cottony-like egg mass at the end of the body of the female insect. 

 Perhaps unnoticed previously, they suddenly attract almost everyone's 

 attention in the month of .June, for the reason that, although prior to 

 that time they have been inconspicuous flat scales of much the same 

 coloration as the bark, in June the brilliant egg mass is pushed out of 

 the body. These insects 

 appear frequently in enor 

 mous numbers on maple 

 trees grown as shade trees, 

 sapping their vitality, and 

 thus becoming of much 

 economic importance. 



The life history of this 

 species was worked out 

 with elaborate care by J. 

 Duncan Putnam, of Dav- 

 enport, Iowa. Mr. Put- 

 nam's paper was published 

 in the Proceedings of the 

 Davenport Academy of 

 Natural Sciences ( Volume 



II, December, 1879, pages Fig. 2.— Pulvinaria innumerabilis: male larva, second stage, 



293-347), and was illustra- 

 ted by two carefully etched 

 plates. His descriptions of the different stages were so carefully drawn 

 that descriptive details maybe omitted from this article. The account 

 of the life history which follows, however, is based upon observations 

 made at Washington and upon notes taken by Mr. T. Pergande, the 

 assistant in charge of the insectary at this office. 



The young lice hatch early in the summer, usually in the month of 

 June, but occasionally at least as early as May 22. The hatching 

 period usually extends on into early July, but may last until August. 

 They soon settle upon the ribs of the leaves, very rarely upon the twigs. 

 They seem to prefer the lower surface of the leaves, but many settle 

 at a later date on the upper surface. It has been noticed that those 

 upon the lower surface seem to grow more rapidly than those upon tbe 

 upper surface. In the course of a month they undergo a molt and 

 begin to secrete a certain amount of wax from the dorsal surface of the 



W 



greatly enlarged, with antenna and leg above, still more 

 enlarged (original). 



