Behavioral effects induced by organic insecticides can be exploited for a sustainable control of the Orange Spiny Whitefly Aleurocanthus spiniferus

Abstract

The Orange Spiny Whitefly (OSW) Aleurocanthus spiniferus (Hemiptera: Aleyrodidae) represents a new serious threat to Citrus spp., grapevine and ornamental plants in the whole Mediterranean area. Such threat urgently calls for the development of a sustainable control strategy, including insecticides compatible with biological control, and applicable also in organic citrus farming that represent an essential part of Mediterranean agricultural economy. Therefore, we evaluated the toxicity and the effects on host searching, oviposition, and probing and feeding behavior exerted on OSW by organic insecticides supposed to have limited side effects on environment and ecosystem services, i.e. sweet orange essential oil (EO), extract of Clitoria ternatea (CT), mineral oil, pyrethrin and azadirachtin. Despite none of the compounds caused a significant mortality of any of the OSW instars, we observed interesting effects on whitefly behavior: (i) EO and pyrethrin showed a relevant repellent effect, with impairment of both adults landing and oviposition on treated plants; (ii) CT and pyrethrin strongly affected probing behavior. Here, in the light of our findings, we discuss possible OSW sustainable control strategies and further research perspectives.

Feeding behaviour and mortality of Philaenus spumarius exposed to insecticides and their impact on Xylella fastidiosa transmission

“…In addition, Cacopsylla pyricola Foerster (Hemiptera: Psyllidae) showed shorter phloem ingestions on plants treated with deltamethrin 42 . Regarding pyrethrin, it was also observed that the effect of this pesticide was more evident during the first hours of the recordings (fast repellent effect); that is, insects exposed to pyrethrin exhibited a reduction in the number of Xc and Xi events and their duration during the first 2 h. A reduction in the probing frequency on plants treated with pyrethrin compared with the control was previously observed on Aleurocanthus spiniferus whiteflies 43 . Moreover, the antifeedant activity of pyrethrins was previously reported on other hemipterans, and this effect is known to decrease over time 44 .…”

“… 42 Regarding pyrethrin, it was also observed that the effect of this pesticide was more evident during the first hours of the recordings (fast repellent effect); that is, insects exposed to pyrethrin exhibited a reduction in the number of Xc and Xi events and their duration during the first 2 h. A reduction in the probing frequency on plants treated with pyrethrin compared with the control was previously observed on Aleurocanthus spiniferus whiteflies. 43 Moreover, the antifeedant activity of pyrethrins was previously reported on other hemipterans, and this effect is known to decrease over time. 44 Nevertheless, the impact of pyrethrin on P. spumarius feeding behaviour and its repellent effect tend to disappear in a few hours, possibly as a result of pyrethrin photolability.…”

Vibrational disruption of feeding behaviors of a vector of plant pathogen

“…It is therefore mandatory to rethink about X. fastidiosa control strategies, developing and applying long-term sustainable tools against vectors and safeguarding the ecosystem services. Manipulation of vector behaviors by confounding the cues used by the insect for host-plant recognition, or reducing host plant suitability and residency time, or interfering with insects' communication during crucial steps of their life cycle, could represent an efficient and environmentally-safe strategy for the containment of vector-borne plant pathogens (Fereres & Moreno 2009;Mazzoni et al 2009;Mokrane et al 2020).…”

Characterization of Antennal Chemosensilla and Associated Chemosensory Genes in the Orange Spiny Whitefly, Aleurocanthus spiniferus (Quaintanca)

“…Due to the serious damage caused by this pest, it has been reported as quarantine pest in many countries (EPPO A2 list 1 ). To date, there are limited studies on A. spiniferus that are mainly focused on population dynamics, insecticide selections, biological control and color plates ( Mokrane et al, 2020 ; Nugnes et al, 2020 ; Tian et al, 2020 ). In this study, we investigated the structure, distribution, and abundance of the antennal sensilla in the adult male and female A. spiniferus by scanning electron microscopy.…”