116 DECIDUOUS FKUIT 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, ding}' 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 settling in rows. (See PI. 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, 



