Comparing sterile male releases and other methods for integrated control of the tiger mosquito in temperate and tropical climates

Léa Douchet,Annelise Tran,Gregory L'Ambert,Thierry Baldet,Jeremy Bouyer,Louis Clément Gouagna,Marion Haramboure,David Damiens,Pierrick Labbé

doi:10.1038/s41598-021-86798-8

Abstract

The expansion of mosquito species worldwide is creating a powerful network for the spread of arboviruses. In addition to the destruction of breeding sites (prevention) and mass trapping, methods based on the sterile insect technique (SIT), the autodissemination of pyriproxyfen (ADT), and a fusion of elements from both of these known as boosted SIT (BSIT), are being developed to meet the urgent need for effective vector control. However, the comparative potential of these methods has yet to be explored in different environments. This is needed to propose and integrate informed guidelines into sustainable mosquito management plans. We extended a weather-dependent model of Aedes albopictus population dynamics to assess the effectiveness of these different vector control methods, alone or in combination, in a tropical (Reunion island, southwest Indian Ocean) and a temperate (Montpellier area, southern France) climate. Our results confirm the potential efficiency of SIT in temperate climates when performed early in the year (mid-March for northern hemisphere). In such a climate, the timing of the vector control action was the key factor in its success. In tropical climates, the potential of the combination of methods becomes more relevant. BSIT and the combination of ADT with SIT were twice as effective compared to the use of SIT alone.

Highlights

The expansion of mosquito species worldwide is creating a powerful network for the spread of arboviruses
The weather-driven abundance model developed by Haramboure et al.[71] in the context of the tropical climate of Reunion Island (Indian Ocean), and which already implements sterile insect technique (SIT) and boosted SIT (BSIT), was modified to (1) adapt it to a temperate climate by taking into account the winter season in Europe, with a diapause phase, and by modifying the values of the parameters to those observed in a temperate c limate[74], and (2) implement other vector control methods (Fig. 1): (a) prevention, through the destruction of breeding sites, (b) ovitraps which capture only females, (c) BGS-traps which capture all adults, and (d) autodissemination of pyriproxyfen (ADT) which contaminate the breeding sites
We assessed the effects of the different control methods and their combinations by measuring the induced reduction rate, i.e., the maximum reduction of fertilized females compared to an untreated population, and the resilience, i.e., the time required for the population to recover similar dynamics to that of the untreated one

Summary

Introduction

The expansion of mosquito species worldwide is creating a powerful network for the spread of arboviruses. To overcome the difficulties of conventional insecticide-based methods to reach cryptic habitats, ADT uses the ovipositing behaviour of females to deliver the lethal agent: female mosquitoes are attracted to artificial breeding sites (stations) impregnated with a biocide, which they transfer to natural breeding s ites[34]. Both methods have shown promising reductions in mosquito populations[35,36,37], but their efficiency relies heavily on the attractiveness and the density of traps and ADT s tations[26,37,38]

Objectives

Methods

Results

Conclusion