Western flower thrips (Thysanoptera: Thripidae) preference for thrips-damaged leaves over fresh leaves enables uptake of symbiotic gut bacteria

Abstract

Abstract.To understand the evolution of insect gut symbionts it is important to determine how they are passed on to the next generation. We studied this process in Erwinia species bacteria that inhabit the gut of western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). This is a polyphagous herbivore and a world-wide pest in agricultural crops. With bacteria in the gut, the thrips larval development time can be shorter and its oviposition rate higher compared to bacteria-free thrips. Bacteria are not directly transmitted from mother to offspring, but larvae acquire bacteria from the leaves right after they hatch. These gut bacteria are present on the leaves on feeding sites used by other thrips before the larvae arrive, probably because these other thrips have deposited bacteria via faeces or regurgitation. In this study we addressed the question whether the transmission route of symbiotic bacteria influences the thrips feeding behaviour, and determined the feeding and oviposition preference of thrips, by giving them a choice between leaves with and leaves without prior grazing by other western flower thrips. This was studied for thrips with and thrips without gut bacteria. Young larvae prefer to feed on leaves that where grazed before by other thrips and females prefer to oviposit on these grazed leaves. These results are in contradiction to earlier studies that have found that thrips larvae fitness is lower on thrips damaged plants than on clean plants. This behaviour does however promote the establishment of gut bacteria in the thrips. The factors determining the preference for thrips-damaged leaves may be the physical leaf damage or odours that are produced by the plant, the bacteria or both.

Interaction of Phytophagous Insects with Salmonella enterica on Plants and Enhanced Persistence of the Pathogen with Macrosteles quadrilineatus Infestation or Frankliniella occidentalis Feeding

“…For instance, Felkey and collaborators [40] reported the inefficacy of sodium hypochlorite to eliminate contamination of Salmonella from stem scars and wounded tomato fruits. Interestingly, the preference of thrips for thrips-damaged leaves over fresh leaves has been previously reported as a mechanism that enables the uptake of symbiotic gut bacteria [41]. In our study, significant S. enterica populations were recovered from F. occidentalis -damaged areas of lettuce leaves.…”

Estimating Bacterial Diversity inScirtothrips dorsalis(Thysanoptera: Thripidae) via Next Generation Sequencing

“…Our results suggest this may also be the case for S. dorsalis . In Frankliniella occidentalis , a geographically ubiquitous association with a near Erwinia species provisionally identified as Pantoea agglomerans , is promoted behaviorally since thrips individuals prefer thrips-damaged leaves (de Vries et al 2006). Future work should investigate whether any of the dominant bacteria identified in S. dorsalis could be maintained in a similar fashion as this could provide a mechanism for the spread of transfected bacteria through the thrips population for the purpose of biological control.…”

“…Thrips on the whole have received little attention regarding this important aspect of arthropod ecology. Previous work has largely focused on the most frequently encountered bacterium (identified as a near- Erwinia species) within a single thrips species, the Western flower thrips Frankliniella occidentalis (de Vries et al 2001a; de Vries et al 2001b; de Vries et al 2004; de Vries et al 2006; Chanbusarakum & Ullman 2008, 2009; de Vries et al 2012) with a few studies on other species (Wells et al 2002; Gitaitis et al 2003; de Vries et al 2008). …”

How Predictable Are the Behavioral Responses of Insects to Herbivore Induced Changes in Plants? Responses of Two Congeneric Thrips to Induced Cotton Plants

“…From the current study it could be argued that F. occidentalis was more attracted to undamaged plants over herbivore damaged plants as a result of induced resistance. However De Vries et al [34] showed that F. occidentalis damaged bean and cucumber plants were more attractive to conspecific females than undamaged plants. This provides further evidence for the context, or system, specificity of such interactions and highlights the danger of broader scale interpretation without specific testing.…”