THE GBAPE 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 

 PI. XVTII, fig. 2.) In some instances the parasites were found under 



Fig. 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 exuviae, 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., CoccopJiagus n. sp., Aphelinus fuscipen- 

 nis How., Prospaltella murtfeldtii How., Ablerus n. sp., and Physcus sp. 



