THE GRAPE SCALE. 119 
in which it formed a new genus; it was later described as Prospaltella 
murtfeldtii How. More than a dozen of these little Hymenoptera 
emerged from the scales on a piece of grape cane about 5 inches long. 
SPECIES REARED BY THE WRITER. 
On May 20, 1911, the writer examined many female scales and 
found that about 80 per cent of the insects were parasitized. (See 
Pl. XVIII, fig. 2.) In some instances the parasites were found under 
Fic. 27.—Cage used in rearing parasites of the grape scale. The parasites come to the light and are en- 
trapped in the glass tubes. After model of the California State Board of Horticulture. (Original.) 
the exuvie, but generally the parasite had emerged, leaving an exit 
hole near the central upper part of the scale. 
Many grape twigs were placed in a parasite rearing cage, shown in 
figure 27, and as the parasites emerged they came to the light and 
were entrapped in the test tubes. 
The following species of the parasites reared were determined by 
Dr. L. O. Howard: Ablerus clisiocampx Ashm., Physcus varicornis 
How., Azotus marchali How., Coccophagus n. sp., Aphelinus fuscipen- 
nis How., Prospaltella murtfeldtii How., Ablerus n. sp., and Physcus sp. 
