The western flower thrips (WFT), Frankliniella occidentalis (Pergande), is a widespread phytophagous thrips species in many crops worldwide, causing damage with the feeding and transmission of Tospovirus. It shows high resistance to insecticides and it is difficult to control. Obligate bacterial symbionts are widespread across many insects, where they are often confined to specialized host cells (or tissues) and are transmitted directly from the mother to her progeny and it is often difficult to assess the multiple details of the relationships. At the beginning of this Ph.D. Thesis, the introductory section offers an overview of the current knowledge on the WFT (morphology, biology and ecology) and the endosymbiotic microorganisms associated with the main pest thrips species. The experimental part of the work investigated some aspects related to the influence of endosymbionts on the biological cycle of WFT and their molecular characterization. More specifically, experimental tests on the influence of the symbionts of some aspects (oviposition, fecundity and longevity) of the life cycle of the WFT, were conducted on laboratory populations of thrips. By using Next Generation Sequencing (NGS) technologies and bioinformatics techniques, substantial results have been obtained on the metagenomic study of the microbiome associated with WFT natural populations, collected on different crops in greenhouses and open fields in southern Italy. For all of the F. occidentalis natural populations that were studied, molecular characterizations based on five gene fragments have also been provided.

La Frankliniella occidentalis (Pergande) è una specie diffusa di tripidi fitofagi su molte colture in tutto il mondo, causando danni con l'alimentazione e la trasmissione di Tospovirus. Presenta un'elevata resistenza agli insetticidi ed è difficile da controllare. I simbionti batterici obbligati sono diffusi in molti insetti, dove sono spesso confinati a cellule ospiti specializzate (o tessuti) e vengono trasmessi direttamente dalla madre alla prole ed è spesso difficile determinare la complessità delle relazioni. All'inizio di questa tesi di dottorato una parte introduttiva offre una panoramica delle attuali conoscenze sul WFT (morfologia, biologia ed ecologia) e sui microrganismi endosimbiotici associati alle principali specie di tripidi parassiti. La parte sperimentale del lavoro è stata articolata attraverso la valutazione dell'influenza degli endosimbionti sul ciclo biologico del WFT e la loro caratterizzazione molecolare. In particolare, i saggi biologici sulle associazioni endosimbiotiche, ed i relativi risultati sull'influenza degli stessi sul ciclo di biologico della specie, sono stati condotti su popolazioni di tripidi di laboratorio. Grazie all’impiego di recenti metodologie molecolari, Next Generation Sequencing (NGS), e con l’uso di tests bioinformatici avanzati, sono stati ottenuti risultati sostanziali sullo studio metagenomico del microbioma associato alle popolazioni naturali del WFT, raccolte su diverse colture agrarie in serra ed in pieno campo in diverse aree del Sud Italia. Per tutte le popolazioni naturali di F. occidentalis, è stata fornita anche la caratterizzazione molecolare, basata su cinque frammenti genici.

Evaluation of biological aspects of Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) in relation to microbiome endosymbiotic associations / Vono, Gregorio. - (2021 Oct 18).

Evaluation of biological aspects of Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) in relation to microbiome endosymbiotic associations

Vono Gregorio
2021-10-18

Abstract

The western flower thrips (WFT), Frankliniella occidentalis (Pergande), is a widespread phytophagous thrips species in many crops worldwide, causing damage with the feeding and transmission of Tospovirus. It shows high resistance to insecticides and it is difficult to control. Obligate bacterial symbionts are widespread across many insects, where they are often confined to specialized host cells (or tissues) and are transmitted directly from the mother to her progeny and it is often difficult to assess the multiple details of the relationships. At the beginning of this Ph.D. Thesis, the introductory section offers an overview of the current knowledge on the WFT (morphology, biology and ecology) and the endosymbiotic microorganisms associated with the main pest thrips species. The experimental part of the work investigated some aspects related to the influence of endosymbionts on the biological cycle of WFT and their molecular characterization. More specifically, experimental tests on the influence of the symbionts of some aspects (oviposition, fecundity and longevity) of the life cycle of the WFT, were conducted on laboratory populations of thrips. By using Next Generation Sequencing (NGS) technologies and bioinformatics techniques, substantial results have been obtained on the metagenomic study of the microbiome associated with WFT natural populations, collected on different crops in greenhouses and open fields in southern Italy. For all of the F. occidentalis natural populations that were studied, molecular characterizations based on five gene fragments have also been provided.
18-ott-2021
Settore AGR/11 - ENTOMOLOGIA GENERALE E APPLICATA
MAGNANO DI SAN LIO, Gaetano
POIANA, MARCO
Doctoral Thesis
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.12318/111730
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