432 MAINE AGRICULTURAL EXPERIMENT STATION. IQI2. 



HOMOPTERA. 



SCALE INSECTS, PLANT LICE AND OTHER BUGS. 



Among the many insects which trouble the agriculturist, 

 there is perhaps no one group which is more injurious than are 

 the Coccidae or scale insects. In Maine there are a number of 

 species but owing to" their small size, and sombre coloring they 

 are often passed unnoticed. The increasing practice of spray- 

 ing of orchard trees by our fruit growers will tend to check the 

 spread of species already established and prevent new ones 

 gaining a foot hold. As the insect has sucking mouth parts and 

 lives upon the juices of the host plants, they must be fought 

 by means of contact sprays, such as oil emulsions, whale oil 

 soap, or lime-sulphur. The last mentioned remedy used late 

 in the winter as a dormant spray,* is especially recommended, 

 for most of the species of scales mentioned in the following 

 account. 



In the preparation of these insects for examination to deter- 

 mine the species it is often necessary to remove them from the 

 plant, treat them for a brief period in caustic potash, and after 

 rinsing them in water, transfer them through several grades 

 of alcohol, clearing in turpentine, or xylol,, or other clearing 

 fluid, and finally mounting on a glass slide in Canada balsam. 

 Many of the scale insects are protected by a scale from which 

 they must be removed before mounting them for examination. 

 The scales which cover the insects in some species resemble each 

 other so closely that the most experienced student of scale in- 

 sects will not identify them without first making balsam mounts. 

 It is therefore essential in the case of some of these species, as 

 for example the San Jose scale, that judgment be suspended as 

 to its identity until a thorough examination can be made. 



A spidiotus ostreaeformis. 



EUROPEAN FRUIT SCALE. 



Curtis, Gardiner's Chronicle III, p. 895, 1843. 



Newstead, Monogr. British Coccidae. I, p. 99. 



Marlatt, U. S. Dept. Agr., Div. Ent., Bui. 20, p. 81. 



* See "Apple Tree Insects of Maine," or "Apple Tree Disease," for 

 method of preparing these sprays. These bulletins may be obtained 

 free of charge by residents of the State upon application to the Director, 

 Maine Agricultural Experiment Station, Orono, Maine. Both have 

 been republished in the Report Agricultural Commissioner for 1910 

 under the title "Apple Tree Enemies of Maine." 



