Table 6 Calculated heat units required for life cycle of females of Tuta absoluta in Merssa-Matrouh governorate during 2012
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 | 12.91 | 5.268 | 799.1 | 7.64 | 221.60 | 104.60 | 0.28 |
March | 31 | 14.94 | 9.67 | 299.80 | 82.64 | 0.38 | ||
April | 30 | 19.25 | 13.98 | 419.40 | 57.16 | 0.52 | ||
May | 31 | 21.47 | 16.20 | 502.20 | 49.33 | 0.63 | ||
June | 30 | 24.13 | 18.86 | 565.80 | 42.37 | 0.71 | ||
July | 31 | 27.00 | 21.73 | 673.63 | 36.80 | 0.84 | ||
August | 31 | 27.40 | 22.13 | 663.90 | 36.11 | 0.83 | ||
September | 30 | 25.55 | 20.28 | 608.40 | 39.4 | 0.76 | ||
October | 31 | 23.73 | 18.46 | 572.26 | 43.29 | 0.72 | ||
November | 30 | 20.54 | 15.27 | 458.10 | 52.33 | 0.57 | ||
December | 31 | 15.82 | 10.55 | 327.05 | 75.74 | 0.41 | ||
January 2013 | 31 | 13.65 | 8.38 | 259.80 | 95.36 | 0.33 | ||
Total | 264.4 | 715.13 | 6.98 | |||||
Average | 20.53 | 59.6 | 0.58 | |||||