The silverleaf whitefly is like a horrible house guest. It arrives uninvited with thousands of friends, trashes the place, eats everything in sight and then sticks you with a clean-up bill that runs into the billions of dollars.
That’s exactly what Bemisia tabaci — the silverleaf whitefly — does to the global agricultural industry every year. In food insecure regions such as East Africa, however, these sap-sucking insects have an even more devastating effect. Here, the silverleaf whitefly attacks the cassava plant, a crucial food source for the region. But, not only does it eat the plant’s leaves, it transmits two cassava-killing viruses. Together, these viruses will wipe out an entire year’s product. For a family, a whitefly infestation suddenly means no food. For the region, it can mean widespread economic devastation and famine.
So far, scientists have struggled to develop consistent defense strategies against these insects. But, with the aid of supercomputing, they’re quickly transforming from hapless hosts to super-charged swatters.
Know the enemy to defeat the enemy
Laura Boykin from the University of Western Australia and a team of researchers are using genomics, evolutionary history and the “Magnus” Cray XC40 supercomputer at the Pawsey Supercomputing Centre to understand and eliminate the whitefly threat. For example, they’ve already exposed one assumption that derailed science for decades. Until recently, scientists thought they were battling a single silverleaf whitefly species. Turns out they’re battling a species complex of at least 34 morphologically indistinguishable species.
Understanding the genetic differences will help scientists and farmers distinguish between harmless and invasive whitefly species, develop targeted defense strategies, and breed whitefly-resistant strains of cassava. In a manner of speaking, they’re creating the world’s most coordinated, comprehensive fly swatting defense ever.
Computationally speaking, however, Operation Fly Swat is enormous. The team is working to analyze the vast amount of genomic data their sequencing machines produce. “We have the task of trying to make sense out of billions of base pairs — billions of As, Ts, Gs and Cs at a time,” says Dr. Boykin.
But, with the petascale power of Magnus, the team is making significant progress. They are generating phylogenetic trees of whitefly species from around the world. Phylogenetic trees represent evolutionary relationships, or genealogy, among species. For this project, the genetic datasets involved thousands of base pairs. Even with only 500 whiteflies in a dataset, the possible relationships between them run into the octillions (a 1 followed by 27 zeros) — a calculation impossible without a supercomputer.
So far, the team has analyzed an entire genetic region for all the global samples. “We’ve done benchmarking against our other systems, and Magnus outperforms them,” says Dr. Boykin.
But, perhaps most importantly, Boykin and her team are making meaningful progress toward distinguishing damaging whiteflies from others and arming scientists with the information they need to develop management strategies. “Magnus is changing the world in agricultural development,” she says.
Read the full case study here.
Kristi Lanier is a senior marketing writer at Cray.
