10
Feb
Study Finds Pesticide-Free and Organic Fields Promote Arthropod Biodiversity and Natural Pest Management
(Beyond Pesticides, February 10, 2026) Species that are integral to pest management allow for crucial ecosystem services that negate the need for pesticides in agricultural or land management practices. In a study published in Agriculture, Ecosystems & Environment, researchers from France find pesticide-free fields promote carabid beetles and spiders, generalist arthropod predators that consume slugs, aphids, and mites, that in turn support healthy, organic systems. The study findings highlight the importance of utilizing farming practices that promote biodiversity and foster natural enemy populations as a pest management strategy. Â
“In this study, we assessed the assemblages of emerging and circulating ground-dwelling carabids and spiders during four months in a continuous mosaic of pesticide-free winter-sown crops under contrasted tillage regimes (minimum vs. conventional tillage) and sown flower strips bordering fields,†the authors describe. They continue: “We detected clear patterns, with high in-field carabid and spider overwintering densities than in adjacent flower strips… Our results also demonstrate the key role of pesticide-free fields under minimum tillage, acting both as a high-quality overwintering site for some dominant carabid species and as a source habitat, as several predator species activity-density responded positively to the increased area of minimum tillage fields in the surroundings.â€
Background
While conventional agriculture and other land management utilize synthetic chemical inputs, a wide body of science shows that these chemical-intensive practices are “associated with a decline of farmland biodiversity, with cascading detrimental effects on the delivery of regulating ecosystem services upon which agricultural production relies.†Instead of using petrochemical pesticides and synthetic fertilizers, the use of organic methods offers a holistic solution. In having pesticide-free land with additional land management practices that support the soil and organisms that provide ecosystem services, crop yields are able to be maintained, and synthetic inputs become obsolete. (See studies here and here.)
As the researchers point out: “Reversing the decline of organisms that provide pest control services requires transforming how we envision and manage agricultural systems. This transition embraces a broad range of alternative farming practices or management systems. Among those, organic farming, conservation agriculture, crop diversification, cover cropping and adjacent non-crop habitats such as flower strips have been shown to enhance pest control services.†These management practices, that do not rely on synthetic inputs, address the ongoing “insect apocalypse,†as well as the overall biodiversity decline that affects ecosystem functioning and stability.
Arthropods are invertebrates with a segmented body, a hard chitinous exoskeleton, and jointed limbs. Within this group, insects are a major class (Hexapoda) and serve critical functions within various ecosystems. “In arable agriculture, ground-dwelling carabid beetles (Carabidae) and spiders (Araneae) are generalist predators that are known to be key pest control service providers,†the authors state. They continue: “Both taxa are highly abundant and active during the crop growing season and although they are often considered as agrobiont [organisms dominating agricultural environments], the two groups are globally negatively affected by intensive farming management. Activity-densities of adults are generally negatively affected by practices such as soil tillage operations and intensive pesticide use.†(See research here, here, here, and here.)
Current available literature on the impact of pesticides on these species primarily focuses on active adults, referred to as circulating individuals, assessing populations and diversity through the use of pitfall traps. “Adult habitat occupancy however results from both emerging assemblages, i.e. individuals that overwinter and emerged within a habitat, and circulating assemblages, i.e. individuals active in a habitat where they do not necessarily have overwintered, and that is especially true for arthropods exhibiting high dispersal abilities and/or larval development that is very different from the adults,†the researchers write. The current study analyzes both emerging individuals and circulating individuals to obtain a clear picture of arthropod diversity within the different management systems.
Study Methodology
This study assesses emerging and circulating carabid beetles and spiders in both semi-natural field margins and pesticide-free winter-sown crops, managed under contrasted tillage regimes to identify effects on biodiversity. This was conducted on an experimental farm near Dijon, France, on the pesticide-free CA-SYS agroecological long-term experiment. The farm itself is a 125-hectare area of arable agriculture, many acres of which are surrounded by a dense network of 3-meter-wide perennial flower strips.
On the farm, two main cropping systems are utilized. The authors note: “The first one is inspired from organic agriculture, is pesticide-free and relies on tillage with the use of inversion ploughing (one year out of three)… The second one is inspired from conservation agriculture, but is pesticide-free and relies on cover cropping during the summer fallow period and direct seeding with no-till when possible or with a seldom use of shallow tillage once before sowing.â€
The assessment includes 17 fields with winter-sown crops in 2023, seven with minimum tillage (MT) and ten with shallow tillage (ST), and their adjacent, densely vegetated flower strips. These fields were sown with multiple types of crops, such as wheat, rye, barley, alfalfa, and beans. Sampling of arthropods occurred in both fields and flower strips, with emergence traps and pitfall traps, 68 of each, to capture both overwintering (resident) and circulating ground dwelling carabids and spiders. “Adult carabid identification was conducted at species level using taxonomic keys, whereas spider identification was conducted to species level for adults,†the researchers say.
Results
The authors share the results of the experiment, including:
- High carabid and spider overwintering densities occur in the pesticide-free fields, while flower strips shelter numerous agrobiont and rare overwintering spider species.
- “We caught 5,792 emerging adult carabid beetles belonging to 59 species in emergence traps, among which 3,228 individuals of 55 species in the bottle traps and 2664 individuals of 36 species in pitfall traps… In addition, we captured 10,585 circulating adult carabids belonging to 48 species, with few dominant species such as Poecilus cupreus, Anchomenus dorsalis and Harpalus affinis.â€
- “In parallel, we caught 3,211 emerging adult spiders belonging to 93 species and 18 families within emergence traps, among which 1,833 individuals of 77 species in bottle traps and 1,378 individuals of 60 species in pitfall traps. In pitfall traps (exterior to emergence traps), we captured 6,570 circulating adult spiders belonging to 93 species and 19 families.â€
- Overwintering carabid beetles are more abundant in areas with minimum tillage. “Here, despite the fact that our study focused on winter-sown crops, we detected some effect of soil tillage regime on carabid beetles and spiders. Differences were less marked for overwintering densities estimated in our pesticide-free fields under conventional soil tillage, more or less comparable with densities found by Djoudi et al. (2019) in organic tilled fields and twice higher than densities estimated in conventional tilled wheat fields.†(See additional study here.)
- Surrounding flower strips exhibit a positive effect on the in-field activity-density of arthropod species. Specifically, two dominant species (the carabid Poecilus cupreus and the spider Agyneta rurestris) prefer these habitats when near tilled fields, suggesting they offer refuge from disturbed environments.
In summary, the researchers state: “Our results confirm the importance of within-field habitats for arthropod overwintering, in the context of this study carried out with annual arable crops grown in open field landscapes. They also reveal a marked beneficial effect of pesticide-free and minimum tillage-based farming as hypothesized, through the provision of high-quality overwintering sites for many carabid species and as source habitat from which individuals redistribute to other habitat types. These effects were globally more pronounced for carabids than for ground-dwelling spiders and there were strong differences between individual species.†(See studies here, here, and here.) This highlights the differential impact of landscape management on nontarget species, particularly for pest predator species of carabid beetles and spiders.
The Organic Solution
As cited in the study, prior research reveals that farm management can impact arthropod diversity. Research (see examples here and here) finds that reducing “the intensity of farming management in-field can enhance arthropod overwintering, either by organic or minimum tillage management, which tend to be more suitable than conventional management.†Additional studies, as covered by Beyond Pesticides in previous Daily News, also highlight the impacts of chemical-intensive agriculture on arthropods, as well as the benefits of organic systems.
One study, entitled “Organic farming fosters arthropod diversity of specific insect guilds – evidence from metabarcoding†and published in Conservation Genetics, showcases the negative effect of chemical-intensive, conventional farm management on insect populations when compared to organically managed meadows. The researchers find that the diversity and biomass of flying insects are higher with organic land management by 11% and 75%, respectively. “We report a higher diversity on organic meadows in comparison with conventional ones, all over the diversity of flying insects and not only based solely on a few species-poor groups as in previous studies,†the authors state. They continue: “We found significant richness differences between management types and increased functionality on organic meadows. Our results imply the superiority of organic farming in comparison to conventional farming in the conservation of insect diversity.†(See Daily News here.)
This research, including the current study, adds to the wide body of science on the benefits of organic practices. Amidst the current crises of biodiversity, climate change, and public health, organic offers a holistic solution to land management, both in agriculture and other areas, that protects the environment and all organisms within it. Add your voice to the organic movement and Tell your U.S. Representative and Senators to become a cosponsor of the Opportunities in Organic Act, which was reintroduced in early 2026 by U.S. Senator Peter Welch and U.S. Representative Jimmy Panetta. To learn more ways to take action and stay informed, sign up now to get our Action of the Week and Weekly News Updates delivered right to your inbox!
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source:
Bannwart, P. et al. (2026) Pesticide-free fields under minimum tillage and flower strips enhance carabid beetles and spiders through increased overwintering and spill over processes, Agriculture, Ecosystems & Environment. Available at: https://www.sciencedirect.com/science/article/pii/S016788092600037X.
