20
Jun
Study Adds to Wide Body of Science Highlighting Benefits of Organic for Insect Biodiversity
Image: Art Page submission from Sara Grantham, “Pollen Song.â€
(Beyond Pesticides, June 18, 2025) A study in Conservation Genetics, entitled “Organic farming fosters arthropod diversity of specific insect guilds – evidence from metabarcoding,†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.â€
The topic of insect biodiversity and the decline of insect populations over the last few decades, also referred to as the insect apocalypse, has been extensively covered by Beyond Pesticides. As previously reported in the Daily News, “Continued Decline in Insect Species Biodiversity with Agricultural Pesticide Use Documented,†insects provide many important services, such as maintaining healthy soil, recycling nutrients, pollinating flowers and crops, and controlling pests. These nontarget insects and beneficial species are at risk due to pesticide exposure, both directly and indirectly, which then affects these essential functions. The pesticide residues that contaminate plants and insects that provide a food source for other organisms can lead to population effects throughout multiple trophic levels. Since the active ingredients in pesticides can affect a wide range of taxonomic groups, they cause harm to numerous species rather than just the target species. (See additional coverage here, here, and here.)
As Dave Goulson, PhD—a speaker at Beyond Pesticides’ 40th National Forum Series—says, the insect apocalypse that is occurring threatens all ecosystems. In an essay in Current Biology, he states, “Insects are integral to every terrestrial food web, being food for numerous birds, bats, reptiles, amphibians and fish, and performing vital roles such as pollination, pest control and nutrient recycling. Terrestrial and freshwater ecosystems will collapse without insects… we may have failed to appreciate the full scale and pace of environmental degradation caused by human activities in the Anthropocene.â€
The researchers in the present study, which focuses on meadows in southern Bavaria (the largest state in Germany), note, “Agricultural intensification and industrialisation have caused severe losses of insect diversity, abundance and biomass across major parts of Central Europe.†(See studies here and here.) They continue: “Habitat destruction and subsequent fragmentation have forced local populations to persist in small and isolated habitat patches, increasing the probability of local extinctions and consequently the gradual loss of species at the landscape level. In addition, the deterioration of habitat quality due to influx of fertilisers and pesticides diminishes habitat quality and threatens particularly species with specific habitat demands and restricted dispersal behaviour.†(See studies here, here, here, and here.)
As is noted in the study: “Temporal changes [change over time] in community composition have so far been demonstrated for a few scientifically well-studied and taxonomically well-known charismatic groups, most often in birds, but also in some invertebrate groups like butterflies, hoverflies or longhorn beetles… However, community trends in most other insect groups, including those of major ecological and economic importance, are far less known. A full picture of insect community trends needs to incorporate these groups, including many ecologically and economically important but taxonomically less resolved, mega-diverse taxa.” (See studies here, here, here, here, here, and here.)
This research analyzes a wide range of species, as the authors utilize metabarcoding and barcode index numbers (BINs) to identify and estimate species diversity and ecological patterns. “Until today, most studies of insect decline focused on a small fraction of taxonomic groups, such as functionally or economically relevant flagship species or groups,†the study notes. “Therefore, a comprehensive picture of the impact of different agricultural management types requires integration of the majority of all insect groups.â€
To achieve this, the researchers sampled insects with Malaise traps on both organically and conventionally farmed meadows over the course of three years. In describing the aim of the study, the authors share: “Based on the taxa detected and their taxon-specific ecological performance, we focus on the following research questions:
- Do organically and conventionally farmed meadows differ in biomass of insects and numbers of taxa?
- Does community structure complexity differ between both meadow types?
- Which traits of the entire communities are fostered in organically and conventionally farmed areas?â€
The six study areas (three organically and three conventionally managed meadows) are located in close geographic proximity but differ in their mowing frequency (approximately twice a year for organic and up to seven times a year for conventional), as well as the usage of non-organic chemical inputs on the conventionally managed land. The traps collected insects from April to October each year and were “emptied twice per month, resulting in a total of 95 single trap data during three years of which 48 trap data came from the organic and 47 trap data from the conventional meadows (one trap bottle was missing),†the researchers note.
After collecting all of the insects, the dry biomass materials were weighted and analyzed, assigning BINs to represent the numbers of consensus orders, families, genera, and species for the samples. As a result, the authors report: “We obtained a total of 7,101,348 reads, which were distributed with 3,790,227 reads on the organic and 3,311,121 reads on the conventional meadows… During the three study years, we found a total of 6,509 different BINs (considered as a proxy for species) from 301 insect families.â€
The study finds that biomass is significantly higher on organic meadows compared to the conventionally farmed ones. “The organically managed meadows returned 11.2% more BINs (5,679) than the conventionally managed ones (5,109), a highly significant difference,†the researchers conclude. They continue: “1,400 BINs (i.e. 22% of all BINs) were only found on the organic meadows… For most families, the comparison of organic and conventional meadows revealed a higher diversity in the organic meadows, irrespective of family size. Particularly rich on organic meadows were the Hymenoptera families Megachilidae, Cynipidae, Diapriidae, the Coleoptera families Buprestidae, Carabidae, and Mordellidae, as well as Thripidae.â€
In terms of trophic guilds (species with similar feeding roles within an ecosystem), all of them, aside from coprophages (organisms that feed on feces), have significantly higher numbers of BINs on organic meadows. However, “10% (coprohages) to 28% (mycetophages) of BINs occurred exclusively on organic meadows†and were not seen on any of the conventionally managed land.
The consistently higher insect diversity and evenness found in the organic meadows highlight how organic land management promotes biodiversity. The study also finds that “40% of seed feeders and 36% of nectar users occurred exclusively on organic meadows,†showing that organisms that provide particular ecosystem services, such as pollination, are supported.
Previous research confirms these findings and offers explanations for the results, as is referenced throughout the study, including:
- One study “evidenced that in particular the specialised species disappear from intensively farmed areas due to lack of specific resources needed for their larval development.†Additional studies (see here and here) show that “species requiring specific habitat features for their larval development or depending on very specific food sources during their adult stage, are much more sensitive to anthropogenic disturbance and habitat homogenisation than generalist species.â€
- “[N]umerous insect species are sensitive to the reduction of plant diversity and in particular disappearance of plant species, as many insect species dependent on specific host plants.â€
- “[N]itrogen input and frequent mowing rather negatively impact plant diversity, and subsequently faunal diversity. This difference is even more pronounced for fungiphages because fungi are reacting even more sensitive on human disturbance, but largely safeguard plant growth and ecosystem health by mycorrhiza symbioses.†(See research here and here.)
- Studies conducted on various insect taxa (see here, here, here, and here) support that organically managed land harbors significantly more arthropod species than the conventional ones, showcasing the ecological value of organic farming.
- Key factors, such as the homogeneous habitat structures, high rates of habitat disturbance, and reduced plant diversity often seen in conventional agriculture, “lead to a reduction in niche availability that ultimately causes the decline of insect diversity.†(See study here.)
As shared in recent Daily News coverage, with large numbers of insects at risk, the reliance on pesticides in agriculture and land management continues to threaten biodiversity, a key driver of ecosystem services. (See more on the importance of biodiversity here and here.) Within this context, organic agriculture and land management provide a holistic solution for enhancing and protecting biodiversity. Ultimately, the only way to ensure the safety of the world’s agricultural systems, as well as natural ecosystems, is to end the use of toxic petrochemical pesticides and synthetic fertilizers.
Beyond Pesticides’ mission is to lead the transition to the widespread adoption of organic management practices that protect biodiversity, public health, and the environment. With organic practices that legally prohibit the use of toxic chemicals, this systems-based approach offers a solution for the current crises we are facing.
Become a member of Beyond Pesticides today to add your voice to the organic movement and sign up to receive Action of the Week and Weekly News Updates to stay informed and engaged. For more information on the benefits of organic, see here and here.
***
🐝 National Pollinator Week for Friday! Time to Spread the Buzz!
In view of EPA’s failure to protect pollinators from pesticides, the lives of those essential insects, birds, and mammals are increasingly dependent on state and local laws that are under threat. In particular, bird species are crucially important for preserving biodiversity, as well as providing ecosystem services such as pollination and mosquito management. Protection of birds and their habitats allows for other organisms, including humans, to prosper.Â
From higher insecticide levels in pesticide-laden nests linked to increased offspring mortality to the threats to seed-eating birds from neonicotinoid-treated seeds, agricultural intensification harms bird species within the U.S. and throughout the world. It has become clear that we cannot count on EPA to protect birds—or the rest of us— from the interconnected threats of pesticide exposure, habitat loss, and climate change.  The alternative is to promote policies at the state and local level that move towards organic land management in agriculture, communities, and homes.  >> TAKE ACTION: Tell your governor and mayor to protect birds by adopting policies that support organic land management. Â
In addition, the Trump administration has removed crucial protections established under the Migratory Bird Treaty Act (MBTA), including those that protect birds from pesticide poisoning. Until 2017, MBTA protected migratory birds from such incidental taking as oil and gas operations, which account for 90% of migratory bird deaths, industrialization, and pesticide use. The Migratory Bird Protection Act (MBPA), introduced in May by Rep. Jared Huffman (D-CA) and Rep. Brian Fitzpatrick (R-PA), will restore protections against an “incidental take,â€â€¯but alone, it only returns to a status quo approach. Additional measures are needed, including a wholescale conversion to organic agriculture and land care, as well as reducing dependence on petrochemicals in other ways.  >> TAKE ACTION: Tell your U.S. Representative to cosponsor the Migratory Bird Protection Act (H.R. 3188). Â
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source:
Habel, J. et al. (2025) Organic farming fosters arthropod diversity of specific insect guilds – evidence from metabarcoding, Conservation Genetics. Available at: https://link.springer.com/article/10.1007/s10592-025-01707-0.
