Table 2 Calculated heat units required for the life cycle of females of Tuta absoluta in Giza governorate from February 2012 to January 2013
Month | No. of days (n) | Average temp. °C (t) | D. zero (x) | Thermal constant (y) | Heat units (degree days) | Duration/days (N) | Rate of generation development (G) | |
|---|---|---|---|---|---|---|---|---|
t − x | n (t − x) | |||||||
February 2012 | 29 | 14.00 | 5.268 | 799.10 | 8.73 | 253.17 | 91.53 | 0.32 |
March | 31 | 16.19 | 10.92 | 338.52 | 73.18 | 0.42 | ||
April | 30 | 23.06 | 17.79 | 533.70 | 44.92 | 0.67 | ||
May | 31 | 26.16 | 20.89 | 647.59 | 38.25 | 0.81 | ||
June | 30 | 28.83 | 23.56 | 706.80 | 33.92 | 0.88 | ||
July | 31 | 30.00 | 24.73 | 766.63 | 32.31 | 0.96 | ||
August | 31 | 29.96 | 24.69 | 765.39 | 32.37 | 0.96 | ||
September | 30 | 27.46 | 22.19 | 665.70 | 36.00 | 0.83 | ||
October | 31 | 25.67 | 20.40 | 632.40 | 39.17 | 0.79 | ||
November | 30 | 21.33 | 16.06 | 481.80 | 49.76 | 0.60 | ||
December | 31 | 16.35 | 11.08 | 343.48 | 72.10 | 0.43 | ||
January 2013 | 31 | 14.58 | 9.31 | 288.61 | 85.80 | 0.36 | ||
Total | 273.59 | 629.31 | 8.03 | |||||
Average | 22.80 | 52.44 | 0.67 | |||||