Table 2. Exponential decay function (y = a*exp [-bx]) describing the decrease in D. citri densities and infestation levels from the edge to the interior of the grove in area-wide surveys.
| Host Plant | Parameter | Value | SE | R2 | Distance to 50% reduction (m) |
|---|---|---|---|---|---|
| D. citri eggs | |||||
| Grapefruit | a | 0.39 | 0.035 | 0.97 | |
| b | 0.025 | 0.005 | 27.7 | ||
| Orange | a | 0.38 | 0.015 | 0.99 | |
| b | 0.016 | 0.002 | 44.0 | ||
| D. citri nymphs | |||||
| Grapefruit | a | 0.86 | 0.233 | 0.73 | |
| b | 0.025 | 0.017 | 28.3 | ||
| Orange | a | 1.33 | 0.463 | 0.65 | |
| b | 0.027 | 0.002 | 25.9 | ||
| D. citri adults | |||||
| Grapefruit | a | 0.30 | 0.069 | 0.79 | |
| b | 0.024 | 0.014 | 29.3 | ||
| Orange | a | 0.43 | 0.055 | 0.95 | |
| b | 0.032 | 0.009 | 21.7 | ||
| % flush shoots infested by D. citri | |||||
| Grapefruit | a | 4.51 | 0.093 | 0.80 | |
| b | 0.021 | 0.013 | 33.1 | ||
| Orange | a | 6.89 | 1.03 | 0.90 | |
| b | 0.024 | 0.0089 | 29.5 | ||