. Bulletin of the Department of Agriculture. Agriculture. 12 BULLETIN 807, U. S. DEPARTMENT OF AGRICULTURE. Table IX.—Grapliw chart of life history of Bruchus rufimanus for seasom of 1911-18 and 1918-19. Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec. Eggs, Larvce, PupsR, Adults, - i 1 Continuous line=1917-18. Broken line=1918-19. Although a few adults may be found as late as June, the majority die before the end of March. During 1917 a number of badly in- fested beans were inclosed in a box. Ten per cent of the weevils were dead by February 1, 50 per cent by March, and 90
. Bulletin of the Department of Agriculture. Agriculture. 12 BULLETIN 807, U. S. DEPARTMENT OF AGRICULTURE. Table IX.—Grapliw chart of life history of Bruchus rufimanus for seasom of 1911-18 and 1918-19. Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec. Eggs, Larvce, PupsR, Adults, - i 1 Continuous line=1917-18. Broken line=1918-19. Although a few adults may be found as late as June, the majority die before the end of March. During 1917 a number of badly in- fested beans were inclosed in a box. Ten per cent of the weevils were dead by February 1, 50 per cent by March, and 90 per cent by the 1st of April. A very few remained alive until June. The re- sults of field observations at Hayward during 1918 as to the preval- ence of weevils in the fields are recorded in figure 5. Each count represents an examination of horse-bean plants for a period of 15 minutes. /<3 ^^ / <a. /o Fig. 5.—Curve showing abundance of broad-bean weevils in a field at Hayward, Calif., 1918. Adults have never been observed in the field before the latter part of March, but it is evident that some of them must live tlirough the winter, hiding in the soil, or among rubbish, leaves, etc. In experi- mental plantings of infested beans, both in the fields and in pots, live adults have been observed to come out of the soil several days after planting. In one case a germinating bean was dug up two weeks after it had been planted, and a live weevil, which had emerged from the bean, was found clinging to it. In another germination. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original United States. Dept. of Agriculture. [Washington, D. C. ?] : The Department : Supt. of Docs. , Govt. Print. Off.
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