. Bulletin. Natural history; Natural history. MAKCH APRIL MAY JUNE JULY AUGUST SEPTEMBER OCTOBER KOVEMSER DECEMBER JAN ^^ CHAMBER AL 1925 ; ^N \ _ riRsr â ' \ / ^ '- â \/ \/ \ '^1 SECOND \ ,' \ tENERATIOM .^1 CEMCRATCM / / \) Mi, / / N /-* â . Ses£R*t y; ?3 5 ' 15 ' 25 5 15 £5 5 ' 15 K 5 (5 i5 5 15 25 5 ' 15 iS 5 S 25 ' S ll tt 5 ^ iS 5 MARCH APRIL SEPTEMBER OCTOBER NOVEMBER DECEMBER JAN. SEPTEMBER OCTOBER NOVEMBER DECEMBER J*N Fig. 11. Curves showing evidence of four generations in cultures in 1919 and 1925. There are normally two generations of chinch hugs per season, but the number may be
. Bulletin. Natural history; Natural history. MAKCH APRIL MAY JUNE JULY AUGUST SEPTEMBER OCTOBER KOVEMSER DECEMBER JAN ^^ CHAMBER AL 1925 ; ^N \ _ riRsr â ' \ / ^ '- â \/ \/ \ '^1 SECOND \ ,' \ tENERATIOM .^1 CEMCRATCM / / \) Mi, / / N /-* â . Ses£R*t y; ?3 5 ' 15 ' 25 5 15 £5 5 ' 15 K 5 (5 i5 5 15 25 5 ' 15 iS 5 S 25 ' S ll tt 5 ^ iS 5 MARCH APRIL SEPTEMBER OCTOBER NOVEMBER DECEMBER JAN. SEPTEMBER OCTOBER NOVEMBER DECEMBER J*N Fig. 11. Curves showing evidence of four generations in cultures in 1919 and 1925. There are normally two generations of chinch hugs per season, but the number may be increased under favorable conditions. In Fig. 11, which shows the histories of selected cultures grown in 1910 and VMo. with the date of starting and the number of individuals present in each, there appears some c\idence of a fourth generation in l!ll!», although there was no interim when \inmg stages were not present in some numbers in that instance. In I'.i-.'.') the nymphs that were brought in from the field were put into the exiierimcntal cages (chambers AL and ALL) on June -JD. Nearly all these nymphs had then progressed to fourth and fifth stages, allhough a few still remained in the first stage. Thus the majority of them in chamber ALL transformed into. 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
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Keywords: ., booka, bookcentury1900, bookdecade1910, booksubjectnaturalhistory
