Organic farming truly works when the land is managed as an ecosystem and not as a factory. On that playing field, the fauna allied to the ecosystem It's much more than a support: it's the missing piece that makes everything fit together. We're talking about insects, arachnids, and vertebrates that control pests, pollinate, recycle nutrients, and serve as an ecological thermometer.When they are present, the system becomes more stable, resilient, and less dependent on chemicals.
In this article we compile, rearrange and explain in straightforward language what technical literature and reference guides say about these allies. You'll find key species, habitat management tactics, greenhouse practices, cultural measures, and even innovative approaches such as the use of biostimulants and biological signaling.The idea is clear: stop “fighting” against nature and learn to work with it.
What is beneficial fauna and why does it matter?
In crop protection, the term "auxiliary fauna" refers to beneficial organisms that help control pests, maintain balance, and improve essential ecological processes of the agroecosystem. It includes predators, parasitoids, pollinators, and also beneficial microorganisms and nematodes.Its presence reduces the need for aggressive pesticide use.
Among the invertebrates, predators such as ladybugs, lacewings, and spiders stand out; and parasitoids such as Aphidius colemani, Trichogramma spp., Aphytis melinus o Citrostichus phyllocnistoides. In pollination, bees and certain dipterans play a decisive role in yield and quality.Whether a crop thrives or suffers is often determined by the "staff" of beneficial insects that inhabit it.
Eco-friendly paper: regular, do not exterminate
The balance is maintained by complex trophic relationships. If we eliminate, for example, predatory wasps like Sphecius speciosus, The cicada population explodes and the natural control dynamic is brokenSpiders, lacewings, ladybugs, predatory mites such as Amblyseius swirskii and numerous parasitoid hymenopterans act as an “ecological insurance.” Replacing them with broad-spectrum insecticides almost always creates a greater imbalance.
Nature rarely wipes a species off the map: it always leaves a fraction of the population to preserve genetic variability and system stability. The sensible agronomic goal is not to eradicate pests, but to keep them below the damage thresholdThis logic of “regulation” is the basis of modern ecological management.
Benefits beyond pest control
Assistants are more than just “controllers”. They pollinate, recycle organic matter, contribute to soil fertility, and function as bioindicators. of the state of the agroecosystem. When they are well represented, the need for intervention decreases, production stabilizes, and the risk of resistance is reduced.
In ecological and regenerative systems, “feeding the soil so that the soil feeds the plant” also involves promoting beneficial bacteria, fungi, nematodes, and predatory soil mites. The native microbiology and soil fauna create the conditions for beneficial insects to find shelter and resourcesclosing the circle between living soil and plant health.
Beneficial fauna as a diagnostic tool
Observing pests and beneficial insects provides clues to management. Aphid or thrips infestations often indicate excess nitrogenSoft leaf tissue due to calcium deficiency favors pests with piercing stylets. Viewing the problem as a symptom leads to root solutions: adjusting nutrition, irrigation, and shelters, not "killing for the sake of killing."
With that approach, The farmer moves from a reactive model to a preventive and adaptive one.Thresholds are monitored, staggered flowering is planned, and the set of natural enemies that support background regulation is protected.
Classical biological control vs. integrative approach
Classical biological control focuses on buying and releasing natural enemies —sometimes exotic ones— to curb specific pests. The integrative approach prioritizes attracting, conserving, and enhancing native beneficial fauna.compatible with the climate and the local agricultural mosaic.
Managing processes and habitats, rather than "applying products", is usually more sustainable and economical in the medium term. It is the basis of what is called conservation biological control., key in Mediterranean scenarios with high pest pressure and high seasonal variability.
Strategies for attracting and retaining assistants
The habitat design makes all the difference. Floral borders with sea alyssum (lobularia maritima), umbellifers, sunflowers and other nectariferous plants feed adult lacewings and parasitoids. Vegetation cover and margins with spontaneous vegetation provide shelter, alternative prey, and microclimates.It is advisable to avoid non-native plants that may be reservoirs of pathogens or do not adapt well to the local climate.
In olive groves, the covers act as "ecological infrastructures" that increase lacewings, hoverflies and other allies, drastically reducing the use of pesticides. Studies on organic farms in Florida showed that intercropping sunflowers increased the presence of beneficial insects even at a distance of 1 meter., with a clear improvement in their abundance compared to areas without flowers.
Biostimulants and biological signaling
Biostimulants—substances and microorganisms that improve plant growth, quality, and resistance—integrate well into these systems. They can encourage defensive responses and, in some cases, increase the attraction of helpers by maintaining more “attractive” and vigorous plants without harmful residues.
Some innovative approaches also propose the use of biological signaling: hormones, metabolites, enzymes, extracts and, in more alternative proposals, homeopathic mother tinctures of beneficial insects , the Chrysoperla carnea o Coccinella septempunctataThe goal is not to "sweep away" the pest, but to disrupt its cycle and give an advantage to beneficial insects, avoiding collateral damage from broad-spectrum chemicals.
Cultural measures that empower support staff
Success depends not only on which species we release, but also on how we cultivate them. Pruning to ensure continuous flowering, avoiding extreme temperatures, and fertilizing wisely It increases the effectiveness of predators and parasitoids.
In greenhouses, adapting pruning and harvesting schedules can sustain stable floral resources and shelters. That simple adjustment improves the reproduction of predatory mites and bed bugs like oriuswhich are key against thrips and other common pests.
Greenhouses: hedges, plant islands and isolation
In protected environments, habitat also matters, and a lot. Specialized firms recommend hedges and “islands” of shelter plants in bands and corridors to keep natural enemies anchored throughout the life cycle, especially when the pest is scarce. Adult parasitoids and some generalist predators need pollen and nectar to complete their life cycle.
The mixtures may include coriander, dill, sage, rue or lavender, in addition to cereals or sunflower depending on the crop and natural enemy to be protected. The result is a more balanced and sustained pest-enemy interaction over time, with nesting and constant resources for the beneficial insects.
Physical isolation matters: double door and mesh with appropriate gauge To control vectors, structural cleaning is carried out at the start of the crop using oil with natural pyrethrin, and before the new planting, sticky traps and well-distributed mating disruption pheromones are used. In addition, the release of the natural enemy is adjusted to the target pest. aphids, whiteflies, thrips, spider mites, caterpillars, mealybugs, broad mites or nezara, among others.
Soil biodiversity is not forgotten. The use of beneficial microorganisms—such as those formulated with Trichoderma— helps control soil pathogens to restore the life of the soil, a key element to sustain the ecological building of the greenhouse.
Examples of allied insects and mites
It is useful to have a list of biological control "headliners" on hand to plan releases or, even better, to design habitats that attract them. These are some emblematic species and their role:
- Coccinella septempunctata (ladybug): can devour dozens of aphids a day in its adult stage. Major predator of aphid colonies.
- Chrysoperla carnea (lacewing): its larvae, nicknamed "aphid lions", are voracious with aphids, whiteflies and eggs of other pests. Key to mild springs.
- Aphidius colemani: parasitoid specialized in aphids; “mummifies” aphids and leaves them sterile. Fine and highly selective work.
- Amblyseius swirskii: predatory mite effective against thrips, whitefly and mites. It works very well in horticultural crops..
- Orius laevigatus: generalist predatory bug; bites thrips, aphids and eggs of various pests. Irreplaceable in protected crops.
- Cryptolaemus montrouzieri: ladybug “cochineal eater”. Very useful in spotlights Pseudococci.
- Aphytis melinus: reference parasitoid against California red scale in citrus. Specific and proven control.
- Leptomastix dactylopii y Anagyrus pseudococci: natural enemies of the cottony cushion scale. They complement strategies in fruit and citrus crops.
- Citrostichus phyllocnistoides: successfully introduced in the Valencian Community for the citrus leafminer. Example of applied biological control.
In protected horticulture, combinations such as Amblyseius swirskii, Orius laevigatus y encarsia formosa Their effectiveness against thrips, mites, and whiteflies is more than validated. They have made it possible to reduce the use of broad-spectrum insecticides with very solid results in a Mediterranean climate.
Vertebrate fauna: allies that go far beyond insects
The word “auxiliary” does not end with invertebrates. Birds, bats, amphibians, reptiles, and mammals collaborate in pest control. and in the restoration of the agroecosystem. Informative guides endorsed by conservation organizations provide simple guidelines for attracting and protecting them.
Insectivorous birds such as great tits and blue tits thrive in mixed woodlands with nest boxes and a diversity of plants; the house sparrow cleans up organic remains and is a "natural sweeper". Swallows and airplanes capture swarms of insects in flightTheir nests should not be removed; they are protected and provide impressive control.
The swift heralds summer with its soaring flight as it devours insects. Among birds of prey, the Spanish imperial eagle keeps rabbits in check in agricultural landscapes, and species like the Montagu's harrier or the common buzzard hunt rodents effectively. Leaving tall trees and perches makes their ecological work easier..
Common and lesser kestrels take advantage of gaps in restored buildings and dovecotes; installing nest boxes and preserving patches of natural vegetation increases their success. Nocturnal birds of prey (owls) are silent rodent controllersThe little owl is very sensitive to rodenticides, so it is advisable to reduce them and provide nest boxes; the barn owl also responds very well to these measures.
Among mammals, mustelids such as weasels, polecats and badgers are effective predators of rodents and rabbits if we preserve riverbanks and ditches with vegetation cover. The adaptable red fox controls small mammals and disperses seedsEven the lynx helps to balance mesopredators and rabbit populations when its presence recovers.
The hedgehog, a frequent victim of roadkill, regulates populations of invertebrates such as crickets, snails and earthworms, maintaining the balance. Bats, nocturnal insectivores in decline due to pesticides, control pests such as the codling moth. and participate in the reduction of vectors of diseases such as the West Nile virus.
Reptiles such as lizards and geckos "comb" walls and scree slopes, and the ocellated lizard helps with micromammals and insects, provided that roadkill and trapping are reduced. Snakes such as the Montpellier snake and the ladder snake eat rodents and are harmless to people.but very beneficial for the countryside.
In amphibians, the common salamander and toads control invertebrates and promote the recycling of detritus. Something as simple as placing ramps in swimming pools and irrigation ponds It prevents drownings and maintains its populations.
Threats and how to mitigate them
Allied wildlife faces everyday dangers: Electrocutions on power lines, falls into wells or dead-end ponds, collisions and, above all, agricultural chemicals that poison the base of the food chain. For decades, "vermin" that we now know are valuable were persecuted; it's time to change our mindset and take care of our allies.
Simple measures—accessible drinking troughs, respect for breeding seasons, noise reduction in nesting areas, feeders in winter or summer—and the installation of nest boxes for barn owls, kestrels and little owls They have a real impact. On farms with recurring vole infestations, these birds of prey can capture hundreds or thousands of rodents per pair per year, surpassing rodenticides in effectiveness and cost.
Legal framework and integrated management
Spanish regulations on the sustainable use of plant protection products recognize beneficial fauna as a fundamental means within Integrated Pest Management. The spirit of the regulatory framework is clear: to prioritize non-chemical techniques, preserve natural enemies, and reduce dependence on pesticides.It fits perfectly with the strategy of habitat management, selective releases and preventive cultural practices.
Cases, data and applied evidence
Research and field experiences support these practices. Habitat management increases the survival and fecundity of natural enemiesincreasing the effectiveness of background control. In hedgerows and flower islands, a greater diversity of predators and parasitoids is observed, and in Mediterranean ground cover, treatments are reduced without loss of performance.
In greenhouses of the Mediterranean arc, protocols that combine plant shelters, physical isolation, pheromones, and targeted releases They have shown very consistent results against aphids, whiteflies, thrips, spider mites, caterpillars, mealybugs, broad mites, and bed bugs such as nezaraWhere the soil is also treated with beneficial microorganisms, the system gains stability.
Training, science and agroecological culture
The transition requires knowledge and skill. Learn to identify beneficial flora, read scientific articles, adjust nutrition, and design shelters This makes all the difference. In addition, there are training programs and practical guides to help translate that knowledge into management decisions that respect the farm's workers and keep it productive.
The combination of field observation and applied science teaches us to “listen” to the crop ecosystem. It's not about collecting products, but about weaving together processes: habitat, resources, timing, diversity and biological signaling that supports long-standing allies.
The key is to create a system that regulates itself: functional habitats (nectar-producing flowers, ground cover, hedges), sensible cultural practices, biostimulants where appropriate, isolation and pheromones in protected areas, and respect for birds, bats, reptiles and amphibiansWith that recipe, pests and diseases stop dictating the agenda, and the beneficial fauna—visible and invisible—returns to doing its job.