Pathogenicity of three formulations of Beauveria bassiana and efficacy of autoinoculation devices and sterile fruit fly males for dissemination of conidia for the control of Ceratitis capitata

Abstract

This study reports the pathogenicity of three formulations of Beauveria bassiana (Balsamo) Vuillemin (Hypocreales) – Bb‐ET, GHA, and Bb‐AES – and their application in panel‐type and cylinder‐type autoinoculation devices, and using sterile males as vectors for the control of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) in coffee‐producing areas of the Central Highlands of Guatemala. Using sterile adults of C. capitata under laboratory bioassays, mean lethal concentrations (LC50) of 1.4 × 107, 2.4 × 106, and 8.2 × 105 conidia ml−1, and median survival times of 4.1 ± 0.1, 4.2 ± 0.1, and 3.8 ± 0.1 days, were recorded for the strains GHA, Bb‐AES, and Bb‐ET, respectively. These values indicate that the three strains were sufficiently pathogenic and that their period of biological activity was considered adequate for using sterile flies as vectors of the inoculum. Observed percentages of sporulated wild C. capitata flies were 57.3, 44.7, and 44.3% for sterile fly vectors, panel devices, and cylinder devices, respectively. The total population reduction at the end of the study period was over 90% for the three treatments. Our results show that sterile males used as vectors or disseminator devices may represent a new control method for area‐wide integrated management of Mediterranean fruit flies. The potential of this new approach and its integration with other control methods, including the sterile insect technique, is discussed.

Compatibility of Beauveria bassiana and alternative phytosanitary products

“…The products tested have a proven insecticidal potential (de Andrade et al 2012), as well as the components of their formula (Alecio et al 2010;Lynn et al 2010;Zorzetti et al 2012;Ekeh et al 2013). In addition, B. bassiana is also pathogenic to a range of insects (Allah et al 2015;Toledo et al 2017;Wraight and Ramos 2017;Yuan et al 2017). However, the association of B. bassiana and APPs or their components may not be additive or synergistic and the products may negatively affect the pathogenicity of the fungus.…”

“…In addition to APPs, entomopathogenic fungi are important for pest control, especially Beauveria bassiana (Balsamo -Crivelli) Vuilemin which is pathogenic to a variety of insects (Pires et al 2010;Potrich et al 2011;Rondelli et al 2012;Huang et al 2013;Alberto et al 2016;Toledo et al 2017).…”

Integration of Entomopathogenic Fungi into IPM Programs: Studies Involving Weevils (Coleoptera: Curculionoidea) Affecting Horticultural Crops

“…Significant control of the red palm weevil R. ferrugineus was reported [ 188 ] and the sexual competitiveness of sterile males was not reduced by sterilisation when compared to non-sterile males [ 291 ]. The combination of the sterile insect technique (SIT) with EPF has also been tested on fruit flies including Mexican fruit fly ( Anastrepha ludens ) [ 21 ], Mediterranean fruit fly ( Ceratitis capitata ) [ 19 ], melon fly ( Bactrocera cucurbitae ) [ 20 ], and peach fruit fly ( Bactrocera zonata ) [ 292 ]. The sterile insect technique alone or used in combination with EPF has shown potential for safe and selective pest control, but, since sterilisation may have a negative impact on sexual competitiveness [ 21 ], further research on optimising sterilisation procedures is needed for each species being targeted.…”

“…Their popularity stems from their potential to control a wide range of insect pests [ 13 , 14 ] and their suitability for organic and sustainable crop production [ 15 ]. In addition to their direct impact on insect pests, EPF have also been reported to act as endophytes within host plants [ 16 ], can be integrated with attractants for attract-and-kill pest management approaches [ 17 , 18 ], and can be combined with sterile males for integration with the Sterile Insect Technique (SIT) [ 19 , 20 , 21 ]. Entomopathogenic fungi may also have synergistic interactions with some beneficial arthropods (predators, parasitoids, pollinators) [ 22 , 23 , 24 ], other entomopathogens (bacteria and nematodes) [ 25 , 26 ] and synthetic insecticides [ 27 , 28 ] that could be exploited within IPM programs on various crops.…”

The Sterile Insect Technique (SIT) – an introduction

“…As Ras et al (2017) also argued, SIT can be used as part of a wider IPM strategy. Toledo et al (2017) presented data on a relatively new topic relevant to SIT in this context, by showing that male medflies intended for use in SIT can be simultaneously deployed as autoinoculation devices for fungal pathogens potentially lethal to insects. Kalajdzic & Schetelig (2017) reported the results from gene editing experiments using Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), a novel pest of fruit crops.…”