My childhood was filled with jigsaw puzzles. Scenes of picturesque alpine villages, coral reefs or African safari animals… all cut up into hundreds of pieces. Farm landscapes were my favorites. How I enjoyed probing how those individual pieces fit together! Where did the farm animals belong, the farmer who ploughed the land, the mosaics of cultivated fields and smaragd-green meadows interspersed with hedgerows or ponds. From the unique vantage point of a stroller, I contemplated those puzzles through the lens of a true systems agronomist. 

I don't recall whether my childhood puzzles also featured agricultural pests, pathogens or weeds - but, given their prominence and ubiquity, I am sure they did. These biota presently reduce crop yields to the tune of 16-34% and those impacts are projected to rise even further under global warming. More so, the pace of new pest or disease arrivals shows no signs of deceleration. To tackle these biotic constraints, synthetic pesticides have increasingly become the default tool  among the world's farmers; over 2010-2020, absolute pesticide use even rose an astounding 153% in low-income countries. Countries such as Indonesia - once champions of biodiversity-driven pest management - are now gluttonous pesticide consumers. As a consequence, chemical pesticides have become prime drivers of global change - causing extensive pollution of terrestrial and aquatic settings, deepening biodiversity loss, jeopardizing food safety and contributing non-negligible carbon emissions. Pesticide-centered crop protection disrupts soil faunal communities i.e., the basis of agri-food production and lies at the core of pervasive social-environmental impacts... but this need not be the case. In fact, the crop protection domain offers a unique leverage point to achieve transformative change in the global food system. 

In this new paper of ours, we use a systematic literature review to dissect pest management science in the Global South. Drawing on published findings from 65 low- to middle-income countries over 2010-2020, we show that science is fragmented by disciplinary specialization, centered on a small slice of (insecticide-resistant) herbivores, geared towards the study of phenomena in simplified (laboratory) ‘microworlds’ and focused on curative control. Though ecological regulation (or biological control) helps to keep pests at bay and its economic value amply surpasses that of pollination, in-depth, context-specific insights are only being gained for the most pressing 2-5% herbivore species. Also, though insects vector (deleterious, but also beneficial) pathogens, act as integrators of below- and above-ground realms and engage in weed seed granivory, all related scientific disciplines orbit in distinct planes and gatekeeping is tight. Warp drive is virtually needed to bridge the intergalactic gaps between pathology, entomology, soil or weed science and breeding! Lastly, though an integration of multiple non-chemical tactics consistently raises the productive performance of cropping systems and bolsters ecosystem service bundles, scientists - as much as farmer practitioners - pursue a siren call for 'easy' single-factor solutions. 

Ladybeetles are voracious predators of (disease-transmitting) herbivores such as aphids or whiteflies, yet their role in biological pest or disease control is only sporadically considered  (Picture: T.T. Khuong)

Interdisciplinary science is pivotal to bolstering food system resilience, but is impeded by deeply rooted pest- or crop-centric approaches. Since the 1960s, holistic perspectives - i.e., the ability to view the farm 'puzzle' instead of its constituent pieces - have been advocated as a guiding premise for sustainable pest management. Yet, sixty years onwards, reductivism -instead of holism - continues to be manifest. Even for herbivores that engage in inter-continental migration, scientific inquiry is almost exclusively geared towards the individual pest, its cultivated host plant and (at times) the field in which such plant is grown. Whether or not those crops are rooted in soil, colonized by bacteria, visited by a myriad of other (non-pest) organisms and molded by fertilizer regimes, legacy effects or companion plants... only the occasional few really care. Farm- and landscape strata are rarely considered while social layers are routinely omitted. Failure to intersect with the behavioral sciences directly explains a broader inability to capitalize on the sizable research progress in agroecological management. Scientists' capacity to meaningfully relate to people is key, as farmers are the ultimate gate-keepers for more sustainable forms of crop protection. In the end, what farmers don't know, they simply cannot use. Yet, in their frantic pursuit of universal remedies, 'silver bullets' and technofixes, many crop protection scientists seem oblivious of the above. As their work is being petrified by abstraction and science risks becoming pointless, society misses out powerful solutions. 

Suddenly incapable of things that we accomplished as infants, our puzzle pieces lay scattered in the room... What happened? How did we get there? Did the PhD process put on blinders that narrow our vision? Or do we knowingly target pest- and crop-centric measures because those underpinned the Green Revolution five decades ago? Under short-cycle projects, traditional experimental set-ups and 'publish or perish' imperatives, is it really too much of a stretch to account for farming system complexities or to engage in cross-disciplinary engagement? Puzzling questions indeed! 

Now, under the current Planetary Emergency, how do we move from here? Do ever more toxic pesticides, gene drives or pest-resistant crop varieties truly carry the answer? Shouldn't they be replaced (or at the very least complemented) with other tools to ensure stable, efficacious and environmentally-sound pest control under disrupted ecosystems and weather anomalies? Do we continue to earn satisfaction from staring with ever greater magnification at single puzzle pieces in the comfort of airconditioned laboratories or monodisciplinary echo-chambers? Or do we opt to get our boots dirty, immerse ourselves into day-to-day farm realities and take time to viscerally explore social-ecological interplay at relevant scales? Do we dare to abandon pesticides altogether and consciously embrace diversity - thus opening all Nature's registers to bolster resilience? With multiple (biotic, abiotic) stressors acting in concert, this plausibly is the best way forward. But... why bother? As agricultural science & technology systems clearly don't help, the choice is entirely ours. It's up to us as individuals to step to the fore and contribute our grain of sand. 

The food system sustainability puzzle surely isn't child's play. Only by viewing all its pieces holistically will we be able to solve it.