. Annals of applied biology. Biology, Economic; Biochemistry. Ll. Lloyd 25 lOth days respectively. In one case where an exact count was made after a fumigation lasting 9 hours on six tomato plants holding scales from 9 days old to mature pupae the mortality was yi per cent. (2900 out of 3184). The fact that the small numbers surviving these fumigations were apparently young for the most part at the time of treatment is difficult to explain as, when smaller doses of cyanide were used, it was found, as other workers have stated, that the jjupae, which would give rise to adults in two or three da
. Annals of applied biology. Biology, Economic; Biochemistry. Ll. Lloyd 25 lOth days respectively. In one case where an exact count was made after a fumigation lasting 9 hours on six tomato plants holding scales from 9 days old to mature pupae the mortality was yi per cent. (2900 out of 3184). The fact that the small numbers surviving these fumigations were apparently young for the most part at the time of treatment is difficult to explain as, when smaller doses of cyanide were used, it was found, as other workers have stated, that the jjupae, which would give rise to adults in two or three days' time, were the most resistant forms. Series of plants were prepared as described above so that in each series one plant held scales representing one day's development from egg to adult; 100 90 80 70 60 50 40 30 20 10. Emergence just begun J L J L J I L A Eggs 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Age of Scales in Days Diagram II. Showing percentage mortalities of scales of A. vajmrariorum of various ages obtained with small doses of cyanide, long exposures. Compare with Diagram I. The gaps on the lower curve ai-e due to the death of three plants. J oz. cyanide per 1000 eft. 1 oz. cyanide per 1000 eft. at one end of the series was a plant holding only eggs, due to begin hatching, and at the other end was one holding mature scales from which emergence of flies had just commenced. Two series were cyanided as follows: (1) 18 tomato plants representing complete development except that three plants died from stem rot and caused gaps; fumigated with I oz. cyanide per 1000 eft., 9 hours' duration; (2) 19 bean plants repre- senting complete development, fumigated with ^ oz. of cyanide per 1000 eft.; 9-| hours' duration. After the treatment the plants were kept for a week and a count was then made of the living or emerged scales and the dead ones, which had by this time turned brown and dried Please note that these images are extracted from scanned page images that may
Size: 2261px × 1105px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectbiochem, bookyear1922
