376 STATE HORTICULTURAL SOCIETY 



duced by a single female is 400. The period during which an individual 

 female will continue producing young lasts for six or seven weeks. The 

 newly born scales are nearly microscopic in size, with bodies oval in 

 shape, when viewed from above, and orange yellow in color. They 

 remain under the mother scale for a short time, finally coming forth to 

 wander about until a suitable place is found to insert their sharp thread- 

 like seta?, by means of which they suck the sap. By this time thread-like, 

 waxy secretions have begun to appear on the back of each little scale. 

 These waxy secretions, together with the cast skins, form the scales. At 

 first there is no difference in appearance between the male and female 

 scales, but according to Howard and Marlatt* the difference becomes 

 apparent after the first molt. Owing to the comparatively long period 

 during which young are produced it is difficult to ascertain the number 

 of generations. Judging from the scales, as they appear in the winter, 

 however, it is probable that young are produced until the latter part 

 of the summer or early in the fall. After all their young have been 

 brought forth the old females die, the young surviving to continue the 

 species. 



Means of distribution. — Locally the active scales are undoubtedly car- 

 ried about by birds, insects, such as beetles, and probably on the clothing 

 of persons working in the infested nurserj^ or orchard. An illustration 

 of this was noticed in one of the nurseries previously referred to. In 

 this nursery it is evident that the scales were first introduced on a few 

 trees. These are very badly infested, those in their immediate vicinity 

 less so, and those four or five rods away still less. Along the road bor- 

 dering this nursery and about forty rods away are a dozen or more pear 

 trees which have been in bearing about two years. These are healthy, 

 vigorous trees and are only very slightly infested, having evidently be- 

 come infested within the past year. It seems very probable that the only 

 way the scales could have been brought to these trees was by some of the 

 means above referred to. 



It is undoubtedly safe to say that the scale is sent broadcast over the 

 country by means of nursery stock more than in any other way. It is 

 true that infested pears from California have frequently been found on 

 fruit stands in some of our eastern cities, but there is very much less 

 chance of spreading the scale in this way than by infested nursery 

 stock. Infested trees dug either in the fall or spring will carry dormant 

 scales. 



Remedial measures. — Various insecticides have been tested in the east 

 against this insect. Eight of the most important of these are discussed 

 in Bulletin No. 87 of this Station. The insecticide which has proved the 

 most successful in the east is whale oil soap. This should be applied 

 at least twice to the infested trees in the fall after the leaves have fallen, 

 at a strength of two pounds to a gallon of water. Another application 

 should be made in the spring before the buds begin to swell. A portion of 

 an infested plum orchaid which was carefully sprayed with whale oil 

 soap at this strength was practically freed from the scale after two 

 applications. It is important to have good whale oil soap. That manu- 

 factured by Legget Bros., 301 Pearl street. New York, and by James 

 Good, 514-518 Hurst street, Philadelphia, is highly recommended. Dr. 



*U. S, Dept. Agr. Div. Ent. Bui. 3, new series, p. 46. 



