As regards fighting against this insect, there are two aspects of its biology which are essential:
- Larvae, although adults lay eggs on the leaves surface, develop and pupate inside the rice stems; that makes them, except during the first larva stages, relatively little sensitive to conventional insecticides.
- Chilo suppressalis populations in the Delta complete up to 3 generations throughout the year; each one of these generations is connected to the rice plant.
As shown in the enclosed table, PROBODELT’s strategy is based on mass trapping of adults with the synthetic sexual pheromone as an attractant and the application of treatment thresholds which make it possible to use insecticides against 2nd and 3rd generation larvae only on areas where pest levels require them. It should be noted that, although insecticides have a very limited action period (between the day it is applied and a few days later), PROBODELT’S application of mass trapping is effective, with no interruption, during the whole flight period of the rice borer.
Control of the borer is started by mid May by putting traps with pheromone on the field for mass trapping of the borer’s male adults.
Simultaneously, at the beginning of the season, the necessary tests are carried out in order to verify if the pheromones used are working properly and if they are not, action will be taken before it is too late and the traps stop capturing. These tests continue to be carried out until the end of the season, by mid September.
By the end of the development of the 1st generation larvae, samplings are carried out to establish the pest density and spot the areas where a possible chemical treatment against 2nd generation larvae might be worthwhile (treatment threshold LLT2).
In the month of August, when the 2nd generation larvae are at an advanced development phase, more samplings are carried out to establish the pest density and spot the areas where a possible chemical treatment against 3rd generation larvae might be worthwhile (treatment threshold LLT3).