THE ROSE APHIS. 5 



Because of the feeding of this rapidly reproducing insect, the flowers 

 may be largely spoiled for decoration, or, since the rose aphis, like 

 all aphides, secretes a sweet sticky liquid called honeydew, the appear- 

 ance of the foliage may be ruined because of the sooty mold that 

 develops where this honeydew has collected. 



HABITS. 



About the time the wingless females become ready to reproduce 

 they leave the parent colony and crawl or migrate to various parts 

 of the rosebush. Upon finding a growing twig or bud, the female 

 settles down with the head pointed toward the ground and begins 

 to feed. In a day or two she begins to give birth to young, which 

 ordinarily range themselves close together around the tender bud 

 or stem behind the adult, and with the heads all pointing downward 

 begin feeding. (PL II.) As the stem or bud becomes crowded 

 many move out until the flower itself is covered with them. As the 

 aphides continue feeding a large amount of honeydew is produced 

 which falls to the leaves beneath, causing a disagreeable stickiness 

 on the leaf, which either becomes covered with dust or black from 

 sooty mold. 



A very slight jar causes the aphides to let go with one pair of legs, 

 and all begin to twitch from side to side on the remaining four legs 

 until quiet is restored, while a severe jar causes many to fall to the 

 ground. A number of the young develop wings, and when mature 

 they fly to other buds and form new colonies. 



When the nymph changes to the winged form the skin splits 

 along the dorsum and the adult crawls slowly out. When newly 

 transformed the adult is light reddish or green in color, with antennae, 

 beak, legs, and cornicles whitish or hyaline, and the wings, which are 

 also white in color, appear as little sacks on the back. In about 

 20 minutes the wings become fully expanded, and two days later the 

 aphis has the colors of the mature insect. 



LIFE HISTORY AND REPRODUCTION IN CALTCORNIA. 



In a climate as mild as that of southern California this insect 

 reproduces continuously throughout the year and undoubtedly is 

 capable of reproducing asexually and viviparously for an extended 

 period. While under observation it has been found giving birth to 

 living young throughout the entire year, and the writer has been 

 unable to find eggs during the same period. It may be that in a 

 climate such as exists in that part of the country, where very cold 

 weather does not occur and where the roses continue to grow all 



