INSECT PESTS OF OHIO SHADE AND FOREST TREES 283 



PUTNAM SCALE 

 , (Aspidiotus ancylus Putn.) 



Description. — Putnam scale so closely resembles the San Jose 

 that quite frequently it is mistaken for the other species. How- 

 ever, it is a much less injurious insect since it multiplies much less 

 rapidly and also since it has a much more limited list of hosts. 



The female scales are of about the same size and shape as those 

 of the San Jose, that is, one-twelfth of an inch in diameter, but the 

 general color is a little darker and the nipple-hke structure is a 

 little to one side instead of being in the center and is brick red in 

 color. (See Plate XLVII, Fig. 2.) 



The male scales are smaller, elongate and with the nipple at 

 one side. 



Life history and habits. — The winter is passed in the partly- 

 grown condition, but the insects are a little farther developed than 

 are the over-wintering San Jose scales. The fragile, winged males 

 appear in April, and the egg-laying females deposit their quota of 

 from 30 to 40 eggs each in the early summer. The eggs are de- 

 posited under the shelter of the scale, and the young, hatching 

 before midsummer, settle upon the bark and form their scale cover- 

 ings. There is but one generation each year. 



Nature of work. — In the role of a shade tree pest this insect is 

 occasionally destructive, infesting trunk, limbs and branches of the 

 host. Under Ohio conditions trees rarely are killed outright by 

 Putnam scale, but it is no uncommon sight to find them injured to 

 the point of unsightliness. 



Food plants. — Soft maple and linden are more susceptible than 

 any other hosts, but in addition to these this scale attacks ash, elm, 

 hackberry, black locust and a number of other trees and shrubs 

 including several of the fruits, such as apple, currant, pear, etc. 



Distribution. — This species occurs throughout the State and 

 over the greater part of the United States. 



Natural enemies. — Hymenopterous parasites are important 

 natural controls as will be noted by the large number of exit holes 

 in the scales of nearly every infestation. 



Control. — The control measures recommended for the San Jose 

 scale are equally effective against this species. 



THE ENGLISH WALNUT SCALE 



(Aspidiotus juglans-regiae Comst. ) 



Description. — Three characteristics render the English walnut 

 scale fairly easy to differentiate from its near relatives, the San 

 Jose, Putnam, etc., even with no more equipment than the ordinary 



