24 



THE BRITISH NATURALIST. [February 



mologist, Signoret, was the first who published any elaborate monograph 

 on the subject ; viz., his Etudes sur les Coccides.''' 



Comstock, the American Entomologist, is another writer on the 

 Coccidae, and his monographs may be found in the United States Govern- 

 ment reports, from 1880 to 1883. Maskell has written a very elaborate 

 treatise on "The Scale Insects of New Zealand," copies of which are, 

 however, very scarce in England, f 



The Chionaspis belongs to the sub-family Diaspidinae, which Maskell 

 defines as "female insects constructing for themselves shields composed 

 partly of secretion, partly of pellicles discarded from earlier stages, 

 abdomen not cleft, legs lost at full growth." 



The family of Chionaspinae is one of the most destructive of the genus. 

 However, it is not the typical form of Scale, but its life-history is interest- 

 ing and may be easily followed. It is found in almost every locality on ash, 

 alder, willow, and other plants. 



A cursory examination shows that two forms of Scale attack ash 

 trees, — the female form (Fig. 3) and the male form (Tig. 6). Sometimes 

 we find both forms on the same tree, at other times only one form is 

 found. In cases where the male form preponderates, a whitish appear- 

 ance is presented. 



If we lift a perfect female Scale at this season of the year (February), 

 and examine it with a lens, or as an opaque object with an inch objective, 

 a considerable number of beautiful red eggs will be noticed (Fig. 4). 

 Now let us follow the development of these eggs (Fig. 1). In 1892 I kept 

 some in confinement in the house, and found they hatched out the first 

 week in May, but I did not find them on the ash trees in the woods until 

 a week or ten days later. By the fourth week in May the bark of the ash 

 trees, at a considerable distance, appeared to the naked eye quite red, 

 caused by millions of the larvae on the bark. These larvae (Fig. 2) are 

 very active, and would measure about the 100th of an inch in length. 

 They possess six legs, comparatively long antennae, two eyes, and two 

 very long transparent hairs at the posterior end. The posterior legs 

 spring from the abdominal part, which is a unique feature in insect 

 anatomy. 



There is no difference between the larval forms of the male and 

 female. But let us first follow the metamorphosis of the female. These 

 larval forms very soon lose their activity, and when they become quiescent 



* This work is very difficult to procure. It first appeared in the Transactions 

 of the Entomological Society of France from 1868101876; and there is no authorized 

 translation. 



t We hear Mr. Morgan, Portugal, also writes on the subject. In England, 

 we have Mr. Douglas, London, and Mr. Newstead, Chester ; the latter has not only the 

 finest collection of these insects, but is the chief authority on Coccids in this country, 

 and it is to him I am indebted for his friendly advice as to their manipulation and 

 classification. 



