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THE ANATOMY OF THE DIASPININE SCALE INSECT 
EPIDIASPIS PIRICOLA (DEL GUER.). 
By Leroy CuHiLps, Stanford University, California. 
The anatomy of several species of scale insects (Coccide) 
has been studied in the entomological laboratories of Stanford 
University, these species representing several different genera, 
such as Physokermes, Ceroputo and Icerya. All these, however, 
are of more or less generalized type and show but little marked 
divergence from a common form. Comparatively little work 
has been done in this laboratory or elsewhere on the anatomy 
of the more specialized Coccide, the Diaspine. 
It is the purpose of this paper to describe the more important 
anatomical characteristics that are representative of the sub- 
family Diaspinze as a whole. A knowledge of the facts of the 
make-up and functions of the parts should add to the interest 
of any study of the sub-family, whether the student have the 
viewpoint of an economic or systematic entomologist. In 
taking a particular member of the sub-family for this study, I 
have chosen the species familiarly known as the Italian pear 
scale Epidiaspis piricola (Del Guer). It is one commonly found 
about the University and in the whole Santa Clara Valley. 
In studying the anatomy of such a small and well chitinized 
insect a number of difficulties of technic present themselves. 
The first thing that must be considered is the method of killing. 
Embedding and cutting were also features that demanded 
considerable experimentation before desirable results were 
obtained. 
Three killing fluids were experimented with in particular; 
Towers’ formula No. 2, Gilson’s, and hot water. The latter 
proved to be the most useful. A fourth, Carnoy’s mixture of 
six parts of absolute alcohol, three parts of chloroform and 
one part of glacial acetic acid, was also used somewhat for 
killing. It brought out the nervous system admirably, but 
the other tissues were badly distorted or destroyed by the action 
of this powerful agent. 
The orienting of the material in the paraffine, ready for 
sectioning, was a little problem in itself, on account of the 
minuteness of the insect. The best results were obtained by 
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