THE HOMOPTERA 



217 



from one-eighth to one-fourth of an inch in diameter and almost hemispherical in 

 form, black in color and with ridges forming an "H" on the back (Fig. 212). 

 The male scales are much smaller, long, narrow and flat. The eggs, from 50 to 

 3,000, are for the most part, laid in May, June and early July, and the adult 

 condition is reached early the next year, though variation from this is frequent. 

 The young scales attack the leaves generally, but 

 later pass to the twigs. The injury they cause by 

 removing the sap from the tree is increased by 

 the honey-dew they secrete, which falling in large 

 amounts on fruit and leaves, forms an excellent 

 material in which a sooty fungus grows, and 

 more or less cuts off light from the leaf surface, 

 thus affecting the growth, and may also clog the 

 stomata or breathing pores on the leaves, besides 

 causing the fruit to look objectionable and need 

 cleaning before its sale. Control of this pest is 

 by Hydrocyanic acid fumigation between Septem- 

 ber 1st and January 1st. Several parasites and 

 enemies are known. One parasite, imported from 

 South Africa, has at times done excellent control 

 work, but has not been continuously effective. 



The Terrapin Scale (Eulecanium nigrofasciatum 

 Perg.). This is a native insect attacking various 

 shade and fruit trees. The scale of the female is 

 nearly hemispherical in form, about one-sixth of 

 an inch in diameter, reddish, mottled and streaked 

 with black (Fig. 213). This insect is viviparous, 

 the young appearing in June and July and be- 

 coming adult the following spring. The young 

 spend a part of their life on the leaves before 

 migrating to the stems. Control, when necessary, 

 is by spraying just before the buds open in spring 

 with miscible oil, using 5 parts of this and 3 parts 

 of gasoline thoroughly emulsified, and 92 parts of 

 water. 



The Cottony Maple Scale (Pulvinaria vitisL.). 

 This insect attacks maple, linden, and other 

 shade trees and plants. The scale of the adult 

 female is rather flat, about one-fourth of an inch 

 in diameter, and by midsummer generally lifted 

 at one end from the twig it is on, by a projecting mass of cotton-like threads 

 which surround 2,000 to 3,000 eggs (Fig. 214). These soon hatch and the young 

 crawl to the leaves and cover themselves with a thin waxy coating. In fall they 

 migrate to the twigs for the winter and become adult the following spring. When 

 abundant the large, white, cotton-like masses make this a very noticeable insect. 

 Contro is by spraying with a miscible oil, 1 part, water 15 parts, just before the 

 buds open in the spring, or with kerosene emulsion, stock 1 part, water 3 parts. 



FIG. 213. Terrapin Scale 

 (Eulecanium nigrofasciatum 

 Targ.), reduced somewhat 

 (right hand figure), and some- 

 what enlarged (left hand 

 figure). (From Houser, Ohio 

 Agr. Exp. Sta. Bull. 332.) 



