Diagnostic, inventaire et stratégie de lutte contre le ver blanc Geotrogus deseticola sur céréales dans la commune de Ain Tolba wilaya D’Ain Temouchent

Abstract

The white grub (Geotrogus deserticola) is a highly polyphagous insect pest that attacks all crops as well as many spontaneous plants. Attacks have been recorded on a national scale, with the most severe being in the West. Until now, cereals have always been the main target of this pest. The larval stages (L2 & L3) cause the most damage. Our present study was carried out on the basis of surveys (monitoring) at the level of the plots of the EURL Bentata Madani ex pilot farm belonging to the private property of the State which is with agricultural vocation particularly cereal located at the commune of Ain Tolba, locality of Sidi Mohamed in the Wilaya of Ain Temouchent in order to deepen the knowledge on the diagnosis and identification of the white grub pest Geotrogus deserticola and to know also the strategy of fight used against this pest and this via a survey "interview" of proximity with the stakeholders of the study zone. The results of the survey revealed that white grubs (Geotrogus deserticola) do exist in infested plots with symptoms in the form of "empty spaces" in the study area, which exceed the nuisance threshold of 9 grubs/m² during the dry period. This allowed us to make an inventory of the collected larvae which confirmed the existence of a significant number of the three larval stages L1, L2 and L3 of Geotrogus deserticola. On the other hand, the second sampling carried out after the rains revealed the existence of only two larval stages L2 and L3 of Geotrogus deserticola, but the L3 stage is the dominant one that is responsible for the damage caused on the cereal crop. The results of the interview survey on the control strategy conducted with stakeholders and neighbouring farmers in the study area revealed that there was no well-planned and specific control strategy against the pest. Neglect, illegal grazing and monoculture contribute to the proliferation of the white grub Geotrogus deserticola