The fallacy of the integrated pest management paradigm and the need for its OFF seasonal shift in the management of tropical fruit flies (Diptera: Tephritidae): The case of Ceratitis capitata

Abstract

The Mediterranean fruit fly (medfly) is a serious frugivorous Afro-tropical pest common in the Mediterranean Region in Europe, which, despite the requirements of Directive 2009/128/EC and the availability of biological methods, is still widely controlled using pesticides.

Our objective was to reassess the suitability of the classical Integrated Pest Management (IPM) paradigm for medfly control and the feasibility of its mission to promote biological methods as an alternative to pesticides. For this purpose, different IPM scenarios were simulated for three hypothetical farms located along the 1000 km latitudinal transect in Italy using the PESTonFARM model.

The simulations revealed a fundamental flaw in the classical IPM paradigm. By disregarding the ability of medfly to inconspicuously increase its population before the economic (action) threshold is reached, it alerts the farmer too late. By then, the medfly population enters the phase of exponential growth, when gradually acting biological methods are unable to cope. The guidelines of classical IPM reinforce the tendency of farmers to focus on large medfly populations during summer, strengthening the reliance on pesticides as the most effective option at the time.

We hereby propose to move away from principles of monitoring-based and threshold-initiated control and target the sparse population of overwintering medflies before they can be detected by monitoring. The control starts on earliest fruits, even if not usually infested to a noticeable extent, and gradually continues to protect subsequent fruits. Our results confirmed that the proposed approach is highly effective, allows for the reliable use of non-pesticide methods of fruit fly control, and therefore ensures that the key ambitions of IPM can be achieved.