Effects of plant virus and its insect vector on Encarsia formosa, a biocontrol agent of whiteflies

Abstract

In this study, we investigated the tritrophic interactions among a persistently transmitted plant virus, Tomato yellow leaf curl virus (TYLCV), its insect vector, the sweetpotato whitefly Bemisia tabaci, and a parasitoid, Encarsia formosa Gahan, one of the most extensively used biological control agents. As an emerging invasive pest worldwide, the two most damaging whiteflies are B. tabaci B and Q cryptic species. On healthy tomato plants, parasitoid-induced mortality was significantly higher in B. tabaci B than in Q. In contrast, similar mortality levels of B and Q were observed on TYLCV-infected plants. A higher rate of parasitism was consistently observed in B, independent of the TYLCV infection. Similarly, the life history traits of E. formosa were influenced by both TYLCV and the two cryptic species of B. tabaci. Specifically, E. formosa parasitizing B had a greater adult longevity and shorter developmental time on healthy plants, whereas the parasitoids developing from Q has a greater adult longevity on TYLCV-infected plants. The emergence rate of E. formosa was unaffected by either B. tabaci cryptic species or the virus. These results suggest that the vector-borne pathogen can manipulate the host suitability of a parasitoid and hence the parasitoid-host interactions.

Compatible and incompatible pathogen–plant interactions differentially affect plant volatile emissions and the attraction of parasitoid wasps

“…The effect of pathogens on herbivore-induced plant volatiles and subsequent volatile-mediated foraging of the natural enemies of herbivores is largely unexplored territory. There has been a recent growing interest in this field, demonstrating how pathogen infection in combination with herbivory may affect the foraging behaviour of parasitoid wasps (Hodge & Powell 2008;De Oliveira, Long & Finke 2014;Liu et al 2014;Martini, Pelz-Stelinski & Stelinski 2014). Notably, in all cases, the interactions studied are that of a pathogen, an insect vector and its parasitoid, with these being of great interest from a co-evolutionary perspective because of the tight link between pathogen and vector.…”

Accumulation of salicylic acid in tomato plant under biological stress affects oviposition preference of Bemisia tabaci

“…To assess the performance of whiteflies on the systemic leaves of ToMV-inoculated and mock-treated plants, the egg hatching and adult emergence rates were examined. The egg hatching test was performed as described by Liu et al (2014) with some modifications. In a small cage (25 mm diameter × 15 mm height), two mated female whiteflies were inoculated on the upper systemic leaves detached from the treated plants.…”

Virus-Infected Plants Altered the Host Selection of Encarsia formosa, a Parasitoid of Whiteflies

“…Encarsia formosa Gahan is a cosmopolitan and commercially important parasitoid of B. tabaci and other whiteflies, and has been widely used to reduce whitefly damage to crops (Gerling et al, 2001 ; Grille et al, 2012 ; Liu et al, 2015 , 2016 ). Parasitism of B. tabaci by E. formosa is affected by the developmental stage of Q and B biotypes (Liu et al, 2016 ) and may also be affected by infection of host plants by TYLCV (Liu et al, 2014 ). In the latter case, parasitism of Q biotype nymphs was higher on TYLCV-infected tomato plants than on TYLCV-free plants, but parasitism of B biotype nymphs did not significantly differ on TYLCV-infected vs. TYLCV-free tomato plants (Pan et al, 2013 , 2014 ; Liu et al, 2014 ).…”

“…Parasitism of B. tabaci by E. formosa is affected by the developmental stage of Q and B biotypes (Liu et al, 2016 ) and may also be affected by infection of host plants by TYLCV (Liu et al, 2014 ). In the latter case, parasitism of Q biotype nymphs was higher on TYLCV-infected tomato plants than on TYLCV-free plants, but parasitism of B biotype nymphs did not significantly differ on TYLCV-infected vs. TYLCV-free tomato plants (Pan et al, 2013 , 2014 ; Liu et al, 2014 ). These studies suggested that the selection of B. tabaci biotype Q and B as hosts by E. formosa may differ and may be affected by TYLCV infection of plants.…”