326 Phylum Arthropoda 



plant may be introduced at the bottom from saucers, or more conven- 

 iently and with little harm through the voile covers of the lantern globes. 

 If the aphids are to be kept for long periods of time at constant tempera- 

 tures, light must be supplied for the plants. This may be done by having 

 one wall of the temperature chamber made of glass and placing an elec- 

 tric lamp outside. If the offspring of certain parents are to be separated 

 into successive groups in the order of their birth, it is better to transfer 

 the parents from one plant to another, leaving the offspring on the plant 

 where they were born. 



The insects are best handled with a moist camel's hair brush. For 

 examination alive under a microscope, the aphids may safely be etherized. 

 They may also, without serious injury, be immersed for a short time in 

 water on a hollow-ground slide to bring out details of structure. 



Family 



COCCIDAE 



METHOD FOR REARING MEALYBUGS, PSEUDOCOCCUS SP.* 



Stanley E. Flanders, University of California 



EARLY investigations by Professor Harry S. Smith in connection with 

 the study of the life history of certain parasites of the Baker mealy- 

 bug indicated that the potato sprout was the most suitable host plant for 

 the latter. While numerous other host plants have been tried, none has 

 yet been found which has the year-round availability of seed potatoes, 

 the adaptability to simple laboratory methods, and the ability to stand 

 the continued abuse of laboratory practices. 



While the propagation of the potato sprouts is a comparatively simple 

 problem, success is dependent upon close attention to several details, the 

 neglect of any one of which may result in failure. 



The first and a very important point to be considered is the selection 

 of seed tubers. In this respect many varieties which possess a reputation 

 for heavy top growth have been tried. The variety known as British 

 Queeri produces an excellent long, succulent, sturdy sprout but seems to 

 retard the development of certain mealybugs with which it is infested. 

 California Burbank also produces an excellent sprout, but not all mealy- 

 bugs will feed on it satisfactorily. Red Rivers and Bliss Triumphs pro- 

 duce an abnormally rapid growth of numerous, large, succulent sprouts, 

 but have exhibited at times a tendency to break down very rapidly under 

 heavy infestation and high temperatures. Idaho Rurals produce very 

 usable sprouts but have too few eyes. 



The Idaho Russet to date has met best all of the requirements of 

 laboratory use. It is readily available on the open market from October 1 



♦Extracted from paper by Harry S. Smith and H. M. Armitage. Univ. Calif. Agri. 

 Exper. Sta. Bull. 509, 193*- 



