. Bulletin. Natural history; Natural history. The Hessian Fly and the Wheat Crop 367 twenty days, while under other conditions it required four years for an individual to complete the same cycle. Under normal weather conditions in Illinois, the relatively fly-free date is September IS for the northernmost tier of counties and pro- gressively later as one goes southward, as shown on the map in Figure -i. Sept lb Sept 22 â Sept 30 -V Oct. 4 Oct 7- Oct. 9. Fig. 4. aiap of Illinois showing normal relatively fly-free dates for wheat Please note that these images are extracted from
. Bulletin. Natural history; Natural history. The Hessian Fly and the Wheat Crop 367 twenty days, while under other conditions it required four years for an individual to complete the same cycle. Under normal weather conditions in Illinois, the relatively fly-free date is September IS for the northernmost tier of counties and pro- gressively later as one goes southward, as shown on the map in Figure -i. Sept lb Sept 22 â Sept 30 -V Oct. 4 Oct 7- Oct. 9. Fig. 4. aiap of Illinois showing normal relatively fly-free dates for wheat 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 Illinois. Natural History Survey Division. Urbana, State of Illinois, Dept. of Registration and Education, Natural History Survey Division
Size: 1221px × 2047px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., booka, bookcentury1900, bookdecade1910, booksubjectnaturalhistory
