December, '09] JOURNAL OF ECONOMIC ENTOMOLOGY 435 



trifoliata, honey locust, American elm and hackberry (Celtis occiden- 

 talis). The superficial appearance of the adult females on different 

 host plants varied remarkably as did also the size and bulk of the 

 ovisacs. 



Further study may reveal other synonyms of this species in the 

 United States and Europe. Newstead, in his Monograph of British 

 Coccidge, has reduced many species names of the early authors to 

 synonymy with P. vitis. 



The Cottony Maple-Leaf Scale 



Pulvinaria acericoJa (Walsh & Riley) 



Plate 19, Fig. 14 



Lecanium acericola W. & R., Amer. Ent., I, p. 14 (1868). 

 Pulvinaria acericola Ckll., Check List, p. 329 (1896). 



This species in the adult stage is usually found only on the leaves 

 of maple, while P. vitis ocexirs invariably on the branches or twigs of 

 its host. This habit means that the latter species, which develops in 

 the younger stages on the leaves and migrates to the twigs before 

 the falling of the leaves, changes location but once, while P. acericola 

 migrates twice during its life history, i. e., from leaf to twig in 

 autumn, and back to the new leaves in the following spring. 



The females of acericola are very distinct from vitis in the more 

 adult stages, having small patches of cottony wax on the dorsum, and 

 developing a very long, fluted ovisac, which is narrower than that of 

 vitis. The microscopic characters are also distinctly different. A 

 complete illustrated discussion of the life history and habits of this 

 scale-insect appeared in Bulletin 22, n. s., U. S. Bureau of Entomology 

 in 1900. 



The Tessellated Scale 



Eucalymnatus tcssellatus (Sign.) 



Plate 20, Fig. 1 



Lecanium tessellatum Sign., An. Soc. Ent. Fr., 5, III, p. 401 (1873). 

 Lecanium perforatum Newst., Ent. Mon. Mag., XXX, p. 233 (1894). 

 Lecanium tessellatum var. perforatum Ckll., Psyche, VIII, p. 90 (1897). 

 Eucalymnatus tessellatus Ckll., Ann. Mag. N. H., 7, IX, p. 453 (1902). 

 Lecanium suMessellatum Green, Cocc. of Ceylon, pt. Ill, p. 206 (1904). 



This species infests a wide range of food plants and is almost un- 

 mistakable in appearance. It is exceedingly flat, usually asymmetri- 

 cal, brown to dark brown, and reveals its remarkable tessellation to the 

 unaided eye. Under the microscope the beautiful pattern is disclosed 



