JAPANESE SPECIES OF PERNICIOUS SCALE. 



167 



and peach are cultivated. In September, it was also detected on the 

 fruits of Apples and pears (introduced from America) which have been 

 sent to me by Marquis Matsudaira, who possesses an orchard at Fukui- 

 Ken lying on the north of Kyoto. Further on my journy, last October, 

 through the northern territories (Akita-Ken, Miyagi-Ken and Yamagata- 

 Ken) where apples and pears are extensively cultivated, I found often the 

 same scale on the fruits of apples, but not on that of pears. 



In some localities, the scales are abundantly found on the trunks 

 as well as the leaves and fruits of pear trees of limited number, and 

 thus their harm is not so extensive as that of the pernicious scale. On 

 the other hand, the apple trees are mostly free of them even when 

 infested, and accordingly they suffer much less than the pear trees. 

 The pernicious scales, according to Prof. Comstock, are limited in the 

 more or less elevated regions, but the allied species may appear in the 

 more or less elevated regions as well as the coast lines as stated before. 



The following are the principal characteristics of our species allied 

 to Aspidiotus perniciosus, Comstock, which I have examined during some 

 past months. 



Female Scales. — They are very variable in form, size and color 

 according to the different stages of their growth as well as in the 

 dead and living conditions. 



The largest full grown scales are mostly round and flat and about 

 2 mm. in diameter. The color varies from dull bluish grey to yellowish 

 grey with a light bluish shade ; but dead scales are mostly darker in 

 color. The exuviae lies either in the centre of the scale or often more 

 or less away from it (Fig. 1. Tab. IV.). It is exclusively roundish and 

 marked with one or more concentric rings ; its color varies from light 

 greyish to dull greyish yellow. The central spot on the exuviae is 

 either dark brown or black, while in young scales it is often tinged 

 greyish yellow. The scar (ventral scale) left on the leaf, branch or 

 trunk of the infested trees after the removal of the scale is represented 

 by a single whitish ring enclosing a large white roundish marking. 



