378 Journal of Agricultural Research voi. x. no. s 



CHARACTER OF THE INJURY 



The work of the mites resembles a gall on the older leaves as well as on 

 the young, developing leaves. They do not generally attack the older 

 leaves, but work mostly on the young leaves just unfolding (Pi. 52, D). 

 The injury noticed on the older leaves is usually done while the leaves 

 are small (Pi. 52, C, D). 



The mites apparently habitually shun the light and consequently pene- 

 trate to the innermost recesses accessible, in accord with the antipathy 

 that this act evinces, especially when suddenly exposed. On the plant 

 they commonly resort to the depressions. The color of the mites is such 

 as to render their detection a matter of more than ordinary difficulty. 



With their styliform mandibles they probe the tissues, in order, ap- 

 parently, to imbibe the juices found there. This action on their 

 part results ordinarily in the appearance of minute brown specks, a 

 sort of russeting. Such marks are often discernible on the inner walls 

 of the curled leaves. The mites suck up the liquid contents of the 

 tissues, leaving the injured parts shriveled. Owing to this injury (PI. 

 52, A, B) and the continued growth about the damaged parts, the leaves 

 are so distorted (PI. 51, A) as to give the plant a very dwarfed and 

 shriveled appearance. Often the leaves become very much thickened 

 at the points immediately surrounding the injured parts. 



The writer found that the buds, both leaf and flower, are ordinarily 

 badly infested. The most noticeable effect from the attacks of this mite 

 is the distortion of the leaves (PI. 52, A), which stunts the plants, and the 

 discloration of the flowers (PI. 52, A, B). Flowers which should have 

 been a soft pink or red come blotched and streaked, and ultimately the 

 blooms wilt and die prematurely. This injury to the flower parts is, of 

 course, mainly noticeable when the flowers are in bloom. Most of the 

 injury is accomplished, however, in the flower-bud stage (PI. 52, C). 

 The mite in all stages of development occurs between the calyx and 

 corolla, within the corolla and on the stamens and ovary. When the 

 infestation on plants is severe, as was the case in most greenhouses 

 visited the past season, the plants appear ultimately so badly curled 

 and distorted as to be unsalable, and they do not bloom normally (PL 

 51, A). 



DESCRIPTION OF TARSONEMUS PALLIDUS 



THE EGG 



The G:gg (PI. 52, E), while very small, is large, considering the size of 

 the adult. It is elliptical and white in color and possesses a pearly 

 appearance, resembling a minute slug egg. It measures from 128 to 

 130 ju in length and 65 to 71 /i in diameter. The surface of the chorion is 

 apparently without any markings whatever, no constrictions occurring. 



