4 BULLETIN 824, U. S. DEPAKTMENT OF AGRICULTURE. 



In 1913 not less than 200,000 pounds of insect flowers and stems 

 were imported at the port of New York from Europe, and in addition 

 large quantities were imported at Baltimore and other ports. In 

 1914, Japan (292) alone sent directly to the United States 379,873 

 pounds of flowers, and during the fiscal year 1917 (June 30, 1916, to 

 July 1, 1917) the total importation was 1,504,000 pounds. During 

 the recent Great War, the European supply was almost entirely 

 cat off. 



CULTIVATION AND HARVESTING OF INSECT FLOWERS. 



An account (5), written in 1856, describes the Pyrethrum plants 

 as growing wild in the Caucasian Mountains at an elevation of from 

 4,500 to 6,800 feet above sea level. These plants blossom in June, 

 and are harvested on a dry day, when an efficient cutter can collect 

 from 30 to 80 pounds a day. The flower heads are usually dried in 

 the sun, although they act more powerfully when the drying is done 

 in the shade. 



Several authors (150, 257, 261) have described the cultivation of 

 insect flowers in Dalmatia. According to a communication, under 

 date of November 13, 1915, from Benjamin F. Chase, United States 

 consul at Fiume, the insect powder there is made from the 

 blooms of a wild chrysanthemum {Pyrethrum cinerarisefolium Trevi- 

 ranus) which grows in profusion on the east side of the Adriatic Sea, 

 from southern Croatia to Montenegro, on the Dalmatian coast, in 

 Herzegovina and Albania. The annual production for all of this 

 territory is given at from 150 to 200 metric tons. That exported 

 is sent chiefly from Trieste, very little going out from Fiume. 

 With the development of the trade in insect powder has come 

 a cultivation of the wild variety. The plant grows best in rocky 

 and barren hills with little soil, especially in limestone formations. 

 Humid or deep soil is not favorable for its growth. Warm and 

 dry weather is supposed to be best, not only to develop the wild 

 plant but to give it its special insecticidal virtue. The cultivated 

 plant does not produce well the first year, but starts the second year, 

 and, if well cared for, continues to grow from the same root for 20 

 years. It begins to bloom in May, and is first harvested in early 

 June. One hectare (2.47 acres) of the cultivated variety yields 

 111,100 plants, producing 2,000 kilograms (4,412 pounds) of dry 

 blooms. The bloom is in best condition for making the powder if 

 cut before opening, or in the "bud." It is cut off just beneath the 

 head. After cutting, the blooms are spread on cloths and dried in 

 the sun. When thoroughly dry they are ground into a fine powder 

 by revolving stones, or by crushers working vertically. The finest 

 quality powder is that obtained from the "buds" or the unopened 

 wild blooms in the region of Krivosije, Dalmatia. The second 



