Modelling the effect of desert locust infestation on crop production with intervention measures

Heliyon. 2021 Jul 30;7(7):e07685. doi: 10.1016/j.heliyon.2021.e07685. eCollection 2021 Jul.

Abstract

The Desert Locust, Schistocerca gregaria(Forskål), is the most devastating migratory pest in the world. The Desert Locust persists as the principal threat to food security in the infested region and beyond. In the inadequacy of reliable and efficient prevention and control measures, strategies for controlling and mitigating the trouble of the Desert Locust are focused on non-risk-free interventions such as chemical pesticides. We formulated and analyzed a mathematical model to assess the impact of this devastating pest on crop production. The theoretical analysis of the model shows that the trivial and locust free equilibriums are unstable, whereas interior equilibrium is asymptotically stable if crop growth rate r is greater than a maturity rate σ Numerical simulations of the model using the baseline parametric values are consistent with theoretical analysis. The conventional scenario projections for crop production (based on the baseline levels of anti-Desert Locust interventions considered in the study) increase by 70.44 % ( 2663.26 ) k g per hectare) if the low depletion pesticide measures performed are maintained proportionally with locust population. This study notes that high-level depletion of the chemical pesticide spray measures could lead to devastating crop losses (similar to those projections before the onset of the pesticide spray) and severe human health and environmental risks. At a baseline harvesting coverage could shelter 44.43 k g to 1176.82 k g per hectare of mature crops. Combining early harvesting and low depletion chemical pesticide with ultra-low volume (ULV) spray devices and formulation could mitigate and eliminate Desert Locust infestation.

Keywords: Crop and locust biomass; Early harvesting; Mathematical model; Numerical result; Pesticides spray; Stability analysis.