Former USDA analyst tells SA: use data, not luck, to stop biosecurity threats

South Africa must use data more effectively to stay ahead of costly biosecurity threats, Prof David Schimmelpfennig, former director of advanced analytics at the US Department of Agriculture's Animal and Plant Health Inspection Service (USDA APHIS), said on 30 October.

Delivering a lecture on the economics of plant and animal biosecurity at Stellenbosch University (SU), where he is an extraordinary professor in the Department of Agricultural Economics, Schimmelpfennig called for a fundamental shift in how the country manages invasive pests and diseases.

"We're looking for a proactive rather than a reactive command response," he said.

The warning lands amid widespread foot-and-mouth disease outbreaks across South Africa and a confirmed African horse sickness (AHS) case near Clanwilliam. That AHS case has put renewed focus on the surveillance and control measures protecting the Western Cape's internationally important disease-free zone. At the same time, invasive and quarantine pests continue to threaten fruit production and are closely monitored in export markets.

Why reactive controls fall short

Traditional biosecurity controls, Schimmelpfennig explained, involve randomly testing imported consignments, detecting a pest and then suspending the affected imports while authorities investigate the source. That model is under strain.

"With increased trade, higher infestations are coming from novel pathways," he noted.

His alternative: combine inspection records, statistical models, and environmental and geographic information systems (computer-based mapping of location data) to identify high-risk commodities, trade routes and operators before an incursion develops into a costly outbreak.

"Can we go further and try to predict the next invasive species or pest before it happens?" he asked.

What the spotted lanternfly taught the US

Schimmelpfennig used the spread of the spotted lanternfly (Lycorma delicatula) in the US to show how invasive pests arrive through unexpected pathways. The insect entered the US on shipments of structural stone or slate from Asia, not on fruit or any other agricultural commodity, and became established in Pennsylvania.

"Every time we drew a new line about the delimitation of the outside area of what the spotted lanternfly had been able to establish, we found out there were satellite populations that got further away," he explained. The pest could attach itself to railway wagons and move into new areas.

"Before you knew it, they were in the next state," Schimmelpfennig said.

Target repeat offenders, spare the compliant

Risk-based sampling could direct limited inspection capacity towards companies and pathways with poor compliance records, he argued.

"If you've been bad in the past and sent us garbage that had pests in it, then we'd sample even more," he said.

But authorities should avoid unnecessarily delaying consistently compliant businesses. "We didn't want to penalise companies that had never sent us pests. So, we reduced the amount of sampling for those [companies], and we increased the amount of sampling that took place on companies that sent us infected goods," Schimmelpfennig explained.

The US also stationed inspectors in important supplying countries, including Chile, to inspect certain products before export.

"It works quite well because we're there, and if there's a problem, we can address it before it gets put on a ship," he said.

Why waiting changes the economics

Delayed intervention changes both the scale of an infestation and the most appropriate response, Schimmelpfennig warned.

"If you wait, the pest might increase the size of its population in the time you wait. So, what happens is you end up with a bigger problem than if you'd done something right away," he said.

A pest detected early might still be eradicated or contained. Once established, eradication can become too difficult or too expensive. "The optimal effort to control the invasive species may change depending on the population," he added.

In follow-up comments to Farmer's Weekly, Schimmelpfennig said South Africa needed to adapt its safeguards to changing trade patterns and an expanding list of potential pests and diseases.

"Biosecurity must work with commodity trading and provide safeguarding in a trade-facilitated environment," he said.

He cautioned, however, that making information available does not guarantee decision-makers will act on it. "It just means it's available for people to decide if they want to," he said.

For South African producers, the practical question now is whether DALRRD (the Department of Agriculture, Land Reform and Rural Development) and industry bodies invest in the data systems and pre-export inspection models Schimmelpfennig described, before the next lanternfly-scale incursion forces a reactive response.