Biological control of desert locust ( Schistocerca gregaria Forskål)

Abstract

Desert locust (Schistocerca gregaria Forskål) is one of the most serious agricultural pests in the world due to its voracity, speed of reproduction, and range of flight. We discuss the current state of knowledge on its biological control using microorganisms and botanical extracts. Metarhizium flavoviride was among the first fungus to be recognized as a bio-control agent against desert locust in the laboratory and field conditions. Nevertheless, its oil formulation adversely affected non-target organisms, hence led to further research on other microorganisms. Metarhizium anisopliae var. acridum (syn. Metarhizium acridum) is an environmentally safer bio-pesticide that has no measurable impact on non-target organisms. However, there are various shortcomings associated with its use in desert locust control as highlighted in this review. Bacterial pathogens studied were from species of Bacillus, Pseudomonas, and Serratia. Botanical extracts of 27 plant species were tested against the locust but showed varied results. Azadirachta indica and Melia volkensii were the most studied plant species, both belonging to family Meliaceae, which is known to have biologically active limonoids. Out of the 20 plant families identified, Apiaceae was the most represented with a frequency of 21%. However, only crude botanical extracts were used and therefore, the active ingredients against desert locust were not identified. Through a comprehensive research, an integrated pest management strategy that incorporates these bio-controls would be a realistic option to control desert locust infestations.

Metrics to Accelerate Private Sector Investment in Sustainable Development Goal 2—Zero Hunger

“…For example, non-climatic drivers of yield decline need moderate to high resolution satellite data to capture field-level decline in leaf area index resulting from infestation [19]. The impact of pests such as the desert locust [20] and fall armyworm [21] can be countered with cost-effective solutions such as integrated pest management [22] coupled with new resistant crop varieties and targeted biological control agents, such as the use of Metarhizium flavoviride fungus as a control agent for the desert locust [20]. Metrics focused on…”

“…For example, non-climatic drivers of yield decline need moderate to high resolution satellite data to capture field-level decline in leaf area index resulting from infestation [19]. The impact of pests such as the desert locust [20] and fall armyworm [21] can be countered with cost-effective solutions such as integrated pest management [22] coupled with new resistant crop varieties and targeted biological control agents, such as the use of Metarhizium flavoviride fungus as a control agent for the desert locust [20]. Metrics focused on raising yields must be able to capture climatic, economic and social outcomes of investment and changes of policy through time [23], and show clearly how new agriculture management strategies, technology and interventions can counter these pests while still reducing poverty and food insecurity (Table S1) [12].…”

Limited Preparedness: Challenges during Desert Locust Management in Kenya

“…To overcome the challenge of geographical remoteness and expansive landscape, the FAO Locust Pesticide Referee Group (LPRG) recommended use of ultra-low volume (ULV) formulated pesticides (FAO, 2021). However, Githae and Kuria (2021) found that ULV pesticides resulted in adverse effects on non-target organisms thus threatening the environment. This environmental risk is associated with use of hazardous petroleum products such as diesel, to carry the active ingredient in ULV pesticides, as a cheaper alternative to plant-based oils.…”

Regional Differences in Control Operations during the 2019–2021 Desert Locust Upsurge

“…However, the control of desert locusts can have negative ecological consequences on non-target organisms [18][19][20]. Organophosphates and carbamates have historically been the most commonly used insecticides as they are fast acting and relatively non-persistent [16].…”

“…For example, Metarhizium anisopliae var. acridum is a biopesticide specific to the family Acrididea, containing desert locusts [20]. However, despite the benefits in minimising the ecological consequences of desert locust control, Metarhizium anisopliae is often not used due to slow action, variable locust mortality and challenges in its production and storage [16].…”