EMULSIONS FOR JAPANESE BEETLE 11 



warm the plants in a room at 70° F. for 48 hours before dipping, and 

 to keep the plants at 70° F. for 48 hours after removal from the dip, in 

 order to promote the larval mortality. 



TREATMENT OF JAPANESE IRIS 



The roots of Japanese iris (Iris kaempferi) are mainly dug in the 

 fall, beginning in September, and shipped immediately for planting. 

 In September tests were made of the susceptibility of these plants to 

 the wormseed-oil emulsion. Twelve plants were immersed for periods 

 of 6, 12, 15, 18, and 24 hours, respectively, in a dip containing 1 cubic 

 centimeter of ascaridole per 6 liters of water, at a temperature of 70° 

 F. (21° C), and the treated plants heeled in or planted in the nursery 

 for further observation. Similar tests were made at the same tem- 

 perature and for the same periods of immersion, but in a dip of twice 

 the strength, i. e., 2 cubic centimeters of ascaridole to 6 liters of water, 

 with the same subsequent treatment. Without exception, the plants 

 came through the tests unhurt, and began to throw out new roots and 

 leaf growth within a few days. The plants apparently withstand 

 nearly twice the period of immersion in twice the concentration of 

 dip necessary to insure mortality of the larvae present in the roots. 



TREATMENT OF PERENNIAL PHLOX 



In this section plants of perennial phlox are dug in the fall, some 

 when in full bloom to fill early orders, and the remainder from that 

 time on until the ground freezes. Care is taken in digging to secure 

 as much of the root system as possible, since the long roots are severed 

 about 3 inches from the stock, cut into l>£-incn pieces, and the 

 pieces sown in coldframes. These root cuttings begin to grow early 

 in the following spring, and are later set out in the field to produce 

 the year's crop. The mature plants, having been trimmed in the 

 manner described, are packed in damp moss and placed in cold storage 

 at 32° F. until February or early March, when they are removed, 

 potted, and placed in the greenhouse and forced slightly for the spring 

 trade. 



It is evident that an insecticide employed to kill any larvae present 

 in or among the roots of this plant must be absolutely nontoxic to the 

 roots, stock, and buds. Tests with wormseed-oil emulsion dip for the 

 control of the larvae in phlox roots were accordingly made at all stages 

 of the harvesting and storage season. The results, the plants in every 

 case being unhurt, indicate that wormseed-oil emulsion is a safe 

 material to use as a means of killing any larvae present in phlox 

 during the period of harvesting and storing it. 



Plants were dug when in lull bloom, and separate lots, each of 

 12 plants, immediately dipped, all at a temperature of 70° F., but 

 each lot for a specified time and in a dip of specified strength. Four 

 lots were dipped for periods of 6, 7, 8, and 9 hours, respectively, in a 

 dip containing 1 cubic centimeter of ascaridole to 6 liters of waters, 

 and three lots for periods of 6, 7, and 8 hours, respectively, in a dip 

 containing twice the proportion of ascaridole. All of these plants 

 came through the treatment unhurt. Immediately after dipping 

 they were set out in the nursery out of doors, and made a normal 

 growth during the subsequent spring and summer, the blooms on the 

 treated plants having in many cases a diameter of 6 to 8 inches. 



