What are the latest developments and trending topics in plant research? To unveil this, our new blog series “Plant research glimpse” highlights relevant recent scientific, peer-reviewed open access publications. We start with a new study published in the Phytoparasatica journal by VIRTIGATION partners LIST and UNICT, which evaluates the longevity of a key whitefly biocontrol agent, the parasitoid Eretmocerus eremicus, under projected future climate change conditions.
Whitefly parasitoids as sustainable biocontrol method
Whiteflies, especially the Bemisia tabaci whitefly, have caused devastation in agricultural systems worldwide. The value chain has relied heavily on insecticides to control this plant pest. However, this form of whitefly control has led to whiteflies becoming resistant to nearly all used groups of insecticides. A more sustainable, widely used, and irreplaceable control measure in greenhouses is biological control through the release of parasitoids, a natural enemy of whiteflies All commercially available whitefly parasitoids are wasps from the genera Encarsia and Eretmocerus, with one of the most used parasitoid species being Eretmocerus eremicus.
The role of climate change in whitefly control
The LIST and UNICT researchers note in their paper that biocontrol by highly specialized natural enemies of whiteflies like the Eretmocerus Eremicus is sensitive to changes in environmental conditions. Especially climate change could
affect the interactions between these organisms, as well as the organisms directly. For example, a recent climate chamber simulation showed that climate change will shorten the development time of the whitefly Bemisia tabaci by almost half, potentially leading to faster population growth in the spring. At the same time, little is known about the development of
Eretmocerus eremicus under projected future climate conditions.
Thus, the LIST and UNICT scientists stress the importance of future climate simulations to understand the effectiveness of biocontrol methods in the future, which also considers daily changes in environmental factors (e.g. food availability). In their study, they investigated the longevity of adult Eretmocerus eremicus parasitoids, one of the most important life-history traits for biocontrol agents. By doing so, the VIRTIGATION entomologists aimed at closing the current knowledge gap, by conducting a climatic chamber simulation to compare how well Eretmocerus eremicus would fare under projected future (hotter) climate conditions vis-à-vis the present ones.
Future climate conditions harm E. eremicus longevity
Through their study, the LIST and UNICT researchers show that under projected future climate conditions, the longevity of the Eretmocerus eremicus is reduced by up to 50%. They found the median survival of this key whitefly parasitoid in the projected future climate to be only 13 days, which is 9 days less than under present climate conditions. While the climate of Luxembourg was taken as focal point for this study, the LIST and UNICT researchers note that it would be likely the same in other Central European climates.
Overall, the findings of the VIRTIGATION entomologists in this study show that future climate conditions will significantly affect the lifespan of the Eretmocerus emericus, thus also reducing the timespan for parasitization, and possibly even limiting its whitefly biocontrol capacity. Ultimately, a shorter release window for this key whitefly parasitoid may require more frequent releases, thus increasing agricultural production cost for the tomato and cucurbit value chain.
More info about LIST and UNICT's new whitefly study
The full version of LIST and UNICT’s study in the Phytoparasitica journal titled “Longevity of the whitefly parasitoid Eretmocerus eremicus under two different climate scenarios” is available online here since 1 July 2023. It has been authored by LIST’s principal investigators Matteo Ripamonti, Michael Eickermann and Jürgen Junk, as well as UNICT’s principal investigator Carmelo Rapisarda. The dataset underlying LIST and UNICT’s peer-reviewed, open access scientific publication is available in the VIRTIGATION Zenodo community. Find out more about VIRTIGATION’s scientific publications on our website here.
