Development of strategies for the incorporation of biological pesticides into the integrated management of locusts and grasshoppers

Abstract

1 Effective biological pesticides based on oil formulation of deuteromycete fungal spores have been developed for use against locusts and grasshoppers. The isolate IMI 330189 of Metarhizium anisopliae (¯avoviride) var. acridum has been registered, extensively ®eld tested and its operating characteristics explored. It should form an powerful component technology in the integrated management of locust and grasshopper pests. 2 The particular advantages of Metarhizium anisopliae were found to be ef®cacy and persistence, low vertebrate toxicity, little environmental impact, conservation of natural enemies and potential for recycling. Additional socio-economic advantages include the possibility of local production, ease of disposal and versatility in use. The principal disadvantages relate to operating characteristics such as slower speed of kill and slightly greater lability in storage than chemical pesticides. 3 Strategies are being developed to integrate biological control agents into locust and grasshopper management schemes; for Metarhizium the accent is placed on: (i) treating the pest before it invades crops and (ii) situations with a high premium on environmental issues. 4 For some pest situations, fast-acting chemical pesticides will still be necessary for crop protection. 5 A cheaper biological agent, such as Nosema locustae, with the capacity to persist in the pest insect population would be useful. Research is recommended on the long-term impact of Nosema in Africa. 6 An evaluation of the utility of the manual destruction of egg pods leads to the conclusion that we should consider the possibility of importing egg parasitoids, such as Scelio parvicornis from Australia, into Africa. 7 Further development work is needed to clarify the economics and politics of locust and grasshopper control; to improve the regulatory framework for biopesticides; to inform key decision makers of the availability and potential of Metarhizium; and to implement the bio-intensive IPM strategies described.

Host–pathogen interactions in a varying environment: temperature, behavioural fever and fitness

“…acridum (Metarhizium flavoviride Gams and Rozsypal (Driver et al 2000)) (Lomer et al 2001). Whilst numerous laboratory and field trials have demonstrated efficacy of these biopesticides in locust and grasshopper biocontrol, the speed of kill following application is highly variable (Hunter et al 1999;Langewald et al 1999;Lomer et al 1999Lomer et al , 2001. This has been found to be due not to poor quality product or application, but to variable ambient temperatures and host thermoregulatory behaviour (Blanford et al 1998Blanford & Thomas 1999aScanlan et al 2001).…”

A case study of the Australian plague locust commission and environmental due diligence: Why mere legislative compliance is no longer sufficient for environmentally responsible locust control in Australia

“…Although for some regions within the APLC's area of responsibility, there remains an acute need for the fast knockdown capabilities of insecticides, specifically, to reduce the potential for locusts to migrate to cropping zones, the use of biological control agents, such as Green Guard, is critical to maintaining the organization's effectiveness. An integrated pest management approach to locust control has been put forward by previous authors (Lomer et al 1999; Hunter 2004), and its implementation is essential for locust‐control agencies, such as the APLC, to successfully balance their core business of locust‐population suppression while maintaining environmental due diligence processes, and therefore, in the case of Australia, their legislated environmental responsibilities.…”

Recent progress in Desert and Migratory Locust management in Africa. Are preventative actions possible ?

“…These products act slowly and are thus inappropriate for emergency situations. However, they should have a role in an integrated control strategy alongside classic insecticides (Lomer et al 1999). They are now available on the locust control market and are part of the FAO (1999) list of products recommended for locust control.…”