116 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 
have been noted and the list of host plants found thus far is as follows: 
Ampelopsis sp., Carya alba, Carya sp., cultivated grape, Platanus 
occidentalis, Platanus sp., European grape (Vitis vinifera), and wild 
grapes (Vitis spp.). 
The records do not show that there is variation among the different 
varieties of grapes as to susceptibility to attack, but it is likely that 
the stronger-growing sorts would be least injured. So far as known 
the grape scale is of no economic importance, except on the grape, but 
it has been the subject of frequent complaint on grapes during the 
past few years and in certain vineyards in the environs of Wash- 
ington its injuries have become decidedly important, requiring treat- 
ment for the preservation of the vines. 
From the above it will be seen that the grape scale is rather widely 
distributed in the eastern United States, occurring from Florida north 
to New Jersey and as far west as Missouri. From published records 
and those in the Bureau of Entomology, it is known to occur in the 
following States: Alabama, Arkansas, Delaware, District of Columbia, 
Florida, Georgia, Illinois, Indiana, Kansas, Kentucky, Maryland, 
Mississippi, Missouri, New Jersey, North Carolina, Ohio, Tennessee, 
Virginia, and West Virginia. It has also been reported from foreign 
countries, being listed from many parts of Europe, from Brazil, 
Jamaica, and the West Indies. 
HABITS AND NATURAL HISTORY. 
Grapevines, when badly infested with the grape scale, have the 
appearance of being coated with a profuse, dingy white scurf. (See 
Pl. XVII.) The scales occur upon the canes, protected by the shreds 
of the exfoliated bark tissue of the previous season’s growth. From 
observations made, this insect seems to have many habits similar to 
those of the San Jose scale (Aspidiotus perniciosus Comst.). The 
grape scale, when abundant, very materially retards the development 
of the vines and always infests the second year’s growth. The young 
“lice” have the peculiar habit of settlmg inrows. (See Pl. XVIII, fig. 
1.) Frequently the canes are so thickly infested that they have the 
appearance of having been treated with a heavy coat of whitewash. 
The insect apparently does not spread readily, as it has often been 
noted that while one vine in a row may be badly infested, not a single 
scale is to be found on adjacent plants. 
The female insect, during the months of May and June, gives birth 
to from 35 to 50 living young. After a brief active stage of about 
two days, the young “lice”’ settle down on the cane and there is a 
fairly uniform development. During the period of growth from the 
immature larva to the adult stage, the insect molts or casts its skin 
twice. As is true with all of the armored scales, the life of this 
insect, with the exception of the short period of activity of the young, 
