10 CALIFORNIA STATE COMMISSION OF HORTICULTURE. 



inal segments of many of our more important species. In the study 

 of scale insects, especially those members of the subfamily Diaspinse, 

 in order to make final determination of the species the first requisite is a 

 good microscope. The last abdominal segment of the adult female 

 presents peculiar organs, designated by distinct names. These terms 

 must be recognized by their various names in order to accurately deter- 

 mine any given species from the technical description. A glossary of 

 the scientific terms used in the descriptions of the Coccidse is presented 

 herewith. On Plate III will be found an illustration of the last 

 abdominal segment of an adult female Diaspina?, showing the form 

 and position of the terms used. By careful study of this figure, aided 

 by the glossary, the technical descriptions will lose their mystification 

 to the beginner, and after a little practice any intelligent person, aided 

 by the microscope, will be able to identify species with some degree of 

 accuracy. 



When the determination of a scale insect is wanted, first observe the 

 name of the host plant upon which it is found, then turn to the list of 

 species and note what scales are found upon that particular plant in 

 California. In case there are several species, note the general descrip- 

 tion of the scale in hand and compare it with the illustrations, and, in 

 many cases, the determination may be made from this alone. If this 

 is not sufficient, read the description of the female, and in this case the 

 final determination calls for the use of the microscope. By following 

 the description and referring to Plate III the various organs used 

 in the determination of the species will be seen and made clear. The 

 descriptions have been systematically arranged according to subfamily 

 and genus. 



GLOSSARY OF TERMS USED IN DESCRIPTIONS, 



Abdomen. All the hinder part of the insect, the third of the three main divisions of the 



body (head, thorax, and abdomen). 

 Anal Lobes; Anal Plates. A small pair of triangular processes forming a valve which 



covers the anal orifice. 

 Anal Orifice. The external opening of the intestine. 

 Anal Ring. A circumscribed ring encircling the anal oriiice. 



Anal Tubercles. A pair of prominent rounded processes on each side of the anal orifice. 

 Antennae. A pair of jointed organs or feelers situated on the head. 

 Appendages. General term for antennce, mouth parts, and legs of an insect. 

 Bicuspid. Having two points. 

 Carina. A Iceel or ridge. 

 Carinated. Keeled, ridged, or ribbed. 

 Castaneous. Shiny, reddish brown. 

 Caudad. Situated toward the tail. 

 Cephalic. Pertaining to the head. 



Cephalothopax. The anterior part of the body, comprising the head and thorax. 

 Chitinous. Consisting of a horny substance present in the sliin and harder parts of 



insects. 



