14 MISC. PUB. 52 6, U. S. DEPT. OF AGRICULTURE 



It is not very poisonous to man but may cause discomfort if in- 

 haled. It should be stored in tightly closed receptacles to prevent 

 the loss of its toxic properties. The commercial product comes 

 chiefly from the European species. 



HOT-WATER TREATMENT 



Immersion of plants, corms, or bulbs in heated water, maintained 

 at a constant temperature ranging from 110° to as high as 120° F. 

 for the period of treatment, is a method used in the elimination of 

 a number of pests, including the gladiolus thrips, aphids, and mealy- 

 bugs on gladiolus corms, the larvae of bulb flies and mites in narcissus 

 and other bulbs, and the cyclamen mite in crowns and distorted 

 growths of some ornamental plants. 



The treatments for these pests vary, and publications dealing with 

 each should be consulted for specific recommendations. Small quan- 

 tities of bulbs or plants can be treated in a laundry tub or similar 

 container, provided that an accurate thermometer is available for 

 checking the temperature. In carrying out the treatment, fill the 

 vessel three-fourths or more full of water, using sufficient hot water 

 to bring the temperature up to the desired point, Submerge the 

 plants or bulbs in screen boxes or loose net bags and add hot water 

 to maintain the desired water temperature, as it is lowered by the 

 cooling effect of material being treated or by radiation. After the 

 bulbs or plants have been warmed to the desired temperature in the 

 bath, less additional hot water will be required to maintain the tem- 

 perature. If the treatment can be carried out in a warm room and 

 the tank kept covered, the temperature will be more easily main- 

 tained. During the entire treating process the water should be stirred 

 with a paddle frequently enough to maintain a uniform temperature 

 throughout the container. Free circulation of the water should not 

 be blocked by the treatment of too many plants or bulbs at one time. 

 The duration of treatment is calculated from the time the tempera- 

 ture is brought up to the desired point after the plant material has 

 been placed in the water. 



The treatments required to control some common pests are : 



The cyclamen mite and broad mite, 15 minutes at 110° F., except 20 minutes for 

 large clumps of delphinium or gerbera and for trays of loosely placed straw- 

 berry plants. 



Bulb mites on tuberoses, narcissus, and other bulbs, 1 hour at 110° F. 



Bulb flies in narcissus and amaryllis, 1% hours at 111° F. 



The grape mealybug on gladiolus corms, 30 minutes at 116° F. 



The gladiolus thrips on gladiolus corms, 30 minutes at 112° F. 



The boxwood leaf miner on boxwood, 5 minutes at 120° F. during late fall and 

 early spring. 



HYDRATED LIME 



Hydrated lime (calcium hydroxide, Ca(OH) 2 X is a finely divided, 

 white powder which can be distributed satisfactorily by dusting ma- 

 chines. Since this domestic product is low priced and readily avail- 

 able, it is used as a filler or diluent in many insecticidal and fungicidal 

 dust mixtures, particularly those containing monohydrated copper sul- 

 fate, sulfur, or arsenicals. It is used in making nicotine dusts. Also, 

 it acts as a safener in calcium arsenate-water sprays. In recent years 



