ENTOMOLOGICAL SOCIETY OF ONTARIO. 89 



appearance, it is the San Jose scal<\ If the disc is smoohh, arid the central point rise3 

 out of a smooth area, it is probably the Putnam scale. Another scale that has come to 

 me several times as the San Jo3e scale, is the Oleander scale, Aspidiotus nerii, Fig. 83, 

 which also attacks ivy. But this is of a lighter color, flatter and longer. 



The Rose scale, Diaspis rosce, has been sent me, both on the rose and raspberry, 

 with the query as to whether or not it was the San Jose scale. But this is also larger, 

 more depressed and of a lighter color. In short, we have nothing that clusters so 

 thickly together on the host plant, and gives it that peculiar gray color, which once 

 seen will never be mistaken for anything else. 



In regard to the life history of the species now uader consideration, it appears to 

 differ from that of many of our scale insects in that instead of reproducing by laying 

 eggs, the mother gives birth to her young. As by far the most careful studies made on 

 this species have been carried on at the Department of Agriculture, under the direction 

 of U. S. Entomologist, Dr. L. O. Howard, I take the liberty of giving Mr. Howard's 

 statement in his own words. He says : " Although this insect has been known in Cali- 

 fornia for about twenty years, its life-history has not been carefully worked out by 

 California writers. Professor Comstock described simply the male and female scales 

 and the body of the adult female. The male was unknown to him. In his work on the 

 Injurious Insects of the Orchard, Vineyard, etc., published at Sacramento in 1883, Mr. 

 Matthew Cooke briefly described the male insect and published a crude figure of it. He 

 further stated that the species produces three broods in California, the first " about the 

 time the cherries begin to color, the second in July, and the third in October." The 

 statement is made by Comstock that the eggs are white," and Cooke further says that 

 " each female produces from thirty -five to fifty eggs." 



" Upon the appearance of the insect in the east, potted pear trees were secured for 

 the Insectary of this division, and colonies of the scale wera established oo them. Their 

 life-history has been followed with more or less cire throughout the seascn, and the fol- 

 lowing brief statement of the life cycle of the insect is based upon daily observations 

 n ade during the summer by Mr. Pergande. 



" It has already been ascertained during the late summer and fall of 1893 that 

 the insect is viviparous, that is, gives birth to living young, and that it does not lay eggs. 

 We are unable to reconcile this condition of affairs with the statements just quoted from 

 Comstock and Cooke, but it occurred to us that, as with certain of the plant-lice, there 

 might be winter eggs, with viviparous females in summer. When winter came on, how- 

 ever, it was found that the insect hibernated in the nearly full grown female condition, 

 and that these females, about the middle of May, began to give birth to living young as 

 their ancestors did the previous fall. In no instance, therefore, have we observed the egg 

 (unless the young still in the body of the female and enveloped in the embryonic mem- 

 brane may be so called). Over-wintered females continued to give birth to living young 

 day after day for six weeks. This condition of affairs produces, early in the season, a 

 confusion of generations, which makes observations upon the life-history of the insect ex- 

 tremely difficult and only to be accomplished by isolation of individuals. It also seriously 

 complicates the matter of remedies, since, as numbers of the larvse are hatching every 

 day, and as they begin to form their almost impervious scales in two or three dayp, a 

 spraying operation at any given time will destroy only those lawae which happen to bi at 

 that time less than three days old, while on the day after the spraying new larvae will be 

 born to take the place of those just killed. 



" Observations upon isolated individuals show that the newly hatched larva?, after 

 crawling about for a few hours, settle down and commence at once to form a scale. The 

 secretion is white and fibrous. In two days the insect becomes invisible, being covered 

 by a pale, grayish-yellow shield, with a projecting nipple at the centre. This nipple is 

 at first white in color. Twelve days after hatching, the first skin is cast. The males at 

 this time are rather larger than the females, and have large purple eyes, while the females 

 have lost their eyes entirely. The legs and antennae have disappeared in both cases. Six 

 days later the males begin to change to pupse, while the females have not yet cast the 



