87 



under a liand leuse the female is dark gray in color, cir- 

 cular and conical in outline, and terminates at the cen- 

 ter bv a nipple like prominence, surrounded by a dis- 

 tinct ring-. The male scales are elongated and smaller, 

 with the nipple near the anterior end. The real insect 

 beneath the scaly covering is plump, circular in outline 

 and yellowish. If crushed with the point of a knife the 

 result is a pale yellowish liquid. The newly-born young 

 are very minute mite-like creatures, long oval in shape, 

 with pale orange color. They are quite active in seeking 

 a suitable spot on which to settle, and in a few hours 

 they have anchored themselves with their beak for life; 

 except in the case of the males, which issue at maturity 

 with wings, and l>ecome active again. 



When a tree becomes crusted over with these scales 

 the bark has the grayish appearance of having been 

 coated over ^^•ith dampened ashes. 



Food Plants. — ^The San Jose scale may be looked for 

 upon the follo^^^ng plants: Peach, plum, apple, pear, 

 apricot, cherry, quince, almonds, rose, Ilawthorn, rasp- 

 berry, spiraea, cotoneaster, prunus pissardii, straw- 

 berry, flowering quince, mountain ash, gooseberry, 

 currant, flowering currant, grape, English walnut, pe- 

 can, black walnut, persimmon, elm, osage orange, lin- 

 den, (Mionymus, weeping willow, Kilmornock willow, 

 English willow, golden willow, cotton-wood, Lombardy 

 poplar, Carolina poplar, catalpa, sumach, silver maple, 

 and perhaps some others. 



Treatment. — For nursery stock, fumigation with 

 hydrocyanic acid gas in an air-tight room is the only 

 safe remedy ; and, in fact, this treatment cannot be con- 

 sidered an absolute surety against the scale, since some 

 unknown opening in the house may allow the gas to es- 

 cape before it has done its deadly work. Where trees 

 are actually known to be infested they should never be 

 used, but should be burned. There is too great a risk 

 in the use of infested stock, no matter to what treat- 

 ment it may have been subjected. Fumigation is a good 

 precaution, and every nurservman should fumigate his 

 stock, not only on account of the probable existence of 

 scale in his nursery, but also on account of other insects 

 that are usually present on nursery trees to a greater or 

 less extent. This work of fumigation is accomplished 



