144 



INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



hymenopterous parasites, Aphycus flavus, Microterys flavus, Cocco- 

 phagus lecanii, and C. lunulatus are the principal ones. 



THE BROWN ELM SCALE 



Leca iiium canadensc (Cockerel!)" 



(Lecanium caryw canadense Cockerell) 



(Fig. 123) 



Description. — The mature females are rich brown, often slightly 

 pruinose, convex and considerably longer than wide. The surface is 



covered with many small ridges ex- 

 tending from the central apex to the 

 margins. The average length is | 

 inch. The young are light brown 

 and quite flat. The eggs are small, 

 slightly oblong and white. This 

 scale is nearest to the frosted scale, 

 Lecanium pruinosum Coq., but is not 

 quite so large, never so frosted and 

 the surface is not so smooth. 



Life History. — The winter is 

 passed in a half-grown condition, 

 maturity being reached in April 

 and May, when egg-laying also 

 begins. Practically all of the eggs 

 are hatched by the first of July. 

 The young settle principally upon 

 the leaves at first and move to the 

 branches before the foliage drops in 

 the fall. Small and large limbs are 

 infested. 



Nature of Work.— The young 

 move from the leaves to the large 

 and small branches, where they at- 

 tain maturity. They usually settle 

 upon the undersides of the limbs 

 and may be thick enough to com- 

 pletely hide the bark. Though ex- 

 ceedingly abundant upon many trees 

 they do not seem to greatly inter- 

 fere with growth but do secrete considerable honey-dew and cause the 

 foliage to appear very unsightly. 



Distribution. — So far the writer has taken or received this scale 

 from Tulare. Alameda, Sacramento, San Joaquin, Fresno, Los Angeles 

 and Yolo counties. Undoubtedly its distribution is much greater. 



Food Plants. — Elm trees, hickory, maple, oak and peach are infested. 

 The elm seems to be the preferred host in this State. 



Control.— Control measures are the same as for the European fruit 

 Lecanjbqim, Lecanium <(n f ni Bouche. 



Fig. 123. — The brown elm scale, Le- 

 canium omadense (Ckll. ). Mature fe- 

 males on elm. Slightly enlarged. (Orig- 

 inal) 



Determined by Geo. B. Kins. Lawrence. Mass. 



