Researchers discovered that imidacloprid, a common pesticide used on crops, damages honey bees by disrupting their ability to eat and maintain proper water balance in their bodies. The good news? A natural compound found in plants called rutin appears to protect bees from some of this damage. Scientists tested these substances on Africanized honey bees and found that imidacloprid reduced how much bees ate and how much weight they gained, while rutin helped bees retain water and partially reversed the pesticide’s harmful effects. This research introduces a new way to measure pesticide damage in bees by examining their body fluids, which could help scientists better understand how chemicals affect pollinator health.

The Quick Take

  • What they studied: How does imidacloprid (a pesticide) affect honey bees’ ability to eat and maintain water balance in their bodies, and can a plant compound called rutin help protect them?
  • Who participated: Africanized honey bees were exposed to different amounts of imidacloprid and rutin in four separate experiments designed to measure changes in eating habits, body weight, water retention, and fluid loss.
  • Key finding: Imidacloprid consistently reduced how much bees ate and prevented them from gaining weight, while rutin helped bees keep water in their bodies and partially reversed the pesticide’s damage. The combination of both substances produced results somewhere in between.
  • What it means for you: This research suggests that pesticide exposure harms bees in ways we couldn’t easily measure before. While rutin shows promise as a natural protector, this is early-stage research. The findings may eventually help farmers and scientists develop strategies to protect bee populations, but more research is needed before any practical applications.

The Research Details

Scientists conducted four separate experiments on Africanized honey bees to understand how imidacloprid and rutin affect their bodies. They exposed bees to three different doses of imidacloprid (0.3, 0.6, or 1.0 ppm—parts per million, a measure of concentration), and tested rutin alone, imidacloprid alone, and combinations of both. They measured multiple things over both short and long time periods: how much food the bees ate, their wet and dry body weight, how much water they retained, and how quickly their body fluids evaporated.

The researchers paid special attention to the bees’ extracellular fluid—the liquid that surrounds cells in the body. They discovered something new: by measuring how fast this fluid evaporates, they could detect signs of stress in the bees even when the bees didn’t show obvious signs of illness or death. This is important because it’s a more sensitive way to spot damage from pesticides.

The study design allowed researchers to see both immediate effects (short-term) and effects that lasted even after exposure ended (long-term), giving a more complete picture of how these substances affect bee health.

Understanding how pesticides harm bees at the biological level—not just whether they survive or die—is crucial for protecting pollinator populations. Previous studies mainly looked at whether bees lived or died, or obvious behavioral changes. This research introduces a new, more sensitive way to detect damage by examining body fluids. This matters because it could help scientists catch pesticide harm earlier and develop better protection strategies. Additionally, testing whether natural plant compounds like rutin can reduce pesticide damage opens the door to potential protective measures that could help bees survive in agricultural areas where pesticides are used.

This research was published in Scientific Reports, a reputable peer-reviewed journal, which means other scientists reviewed the work before publication. The study used multiple experiments (four separate tests) rather than just one, which strengthens confidence in the findings. The researchers measured multiple outcomes (eating, weight, water retention, and fluid evaporation) rather than just one thing, providing a more complete picture. However, the study was conducted in controlled laboratory conditions with one type of bee, so results may not perfectly match what happens in real-world bee colonies or with other bee species. The sample size wasn’t specified in the abstract, which is a limitation for understanding how many individual bees were tested.

What the Results Show

Imidacloprid consistently reduced how much food bees ate across all three dose levels tested (0.3, 0.6, and 1.0 ppm). This reduced food intake led to bees gaining less weight than untreated bees. The effect was dose-dependent, meaning higher doses caused more damage. Rutin had the opposite effect—bees that received rutin ate more and gained more weight than control bees. When bees received both imidacloprid and rutin together, the results fell somewhere in between, suggesting that rutin partially protected bees from the pesticide’s harmful effects on eating and weight gain.

One of the most interesting findings involved the bees’ body fluids. The researchers discovered that fluid from bees exposed to imidacloprid evaporated more slowly than fluid from untreated bees. This suggests that imidacloprid changes the chemical properties of the fluid itself, not just how much fluid the bees have. This was a new discovery—scientists hadn’t used fluid evaporation as a way to measure pesticide damage in bees before.

The changes in body weight and water retention persisted in some cases even after the bees were no longer exposed to the substances, suggesting that the effects weren’t temporary but caused lasting changes to bee physiology.

The study found that rutin’s protective effects were most noticeable in bees exposed to imidacloprid. Rutin alone didn’t dramatically change bee physiology compared to untreated bees, but when combined with imidacloprid, it reduced some of the pesticide’s harmful effects. The dose of imidacloprid mattered—higher doses caused more severe problems with eating and weight gain. The fact that these physiological changes persisted beyond the exposure period suggests that imidacloprid may cause lasting damage to bee metabolism and water balance systems.

Previous research has shown that imidacloprid harms bees by affecting their nervous system and behavior, making it harder for them to find food and navigate. This study adds to that knowledge by showing that imidacloprid also disrupts the physical and chemical properties of body fluids and water balance—a different mechanism of harm that hadn’t been well-studied before. The finding that a plant compound (rutin) can partially protect bees is relatively novel and suggests a new direction for research into protecting pollinators. Most previous studies focused on preventing pesticide exposure rather than mitigating its effects once exposure has occurred.

The study was conducted in controlled laboratory conditions, which may not perfectly reflect what happens in real bee colonies in nature or on farms. Only one type of bee (Africanized honey bees) was tested, so results may differ for other bee species. The abstract doesn’t specify how many individual bees were used in each experiment, making it difficult to assess the statistical power of the findings. The study measured effects in individual bees rather than in whole colonies, so it’s unclear whether these physiological changes would affect colony-level outcomes like honey production or colony survival. The doses of imidacloprid used were specific concentrations; real-world exposure might be different. Finally, while rutin showed promise, it was only tested in laboratory conditions—it’s unknown whether bees could consume enough rutin in nature to get protective benefits.

The Bottom Line

Based on this research, there are no direct recommendations for consumers or beekeepers yet, as this is early-stage laboratory research. However, the findings suggest that: (1) Reducing pesticide use, particularly neonicotinoids like imidacloprid, remains important for bee health; (2) Future research should explore whether natural plant compounds could help protect bees in agricultural settings; (3) Scientists should continue developing sensitive ways to measure pesticide damage in bees. These recommendations have moderate confidence because they’re based on controlled laboratory studies that need to be confirmed in real-world conditions.

Farmers and agricultural companies should care about this research because it provides new evidence of how pesticides harm bees and suggests potential protective strategies. Beekeepers should be interested because it highlights the importance of minimizing pesticide exposure. Environmental regulators and policymakers should consider this research when making decisions about pesticide approval and use. Scientists studying pollinator health should pay attention to the new measurement method (fluid evaporation) as a tool for detecting pesticide damage. General consumers who care about bee health and food security should understand that pesticide use affects bees in multiple ways. This research is less immediately relevant to people who don’t work with bees or agriculture, though bee health affects everyone through pollination of food crops.

This research doesn’t provide information about realistic timelines for seeing benefits because it’s a laboratory study, not a real-world intervention. If rutin were eventually developed as a protective supplement for bees, it would likely take several years of additional research to determine effective doses, delivery methods, and real-world effectiveness. Any protective benefits would probably need to be ongoing—stopping the protective measure would likely result in bees becoming vulnerable again to pesticide exposure.

Want to Apply This Research?

  • Users interested in bee health could track pesticide use in their area (if they’re farmers or gardeners) by logging applications of imidacloprid or other neonicotinoids, noting dates, amounts, and locations. This data could help correlate pesticide use with local bee population observations.
  • For farmers or gardeners: Consider reducing or eliminating imidacloprid use and exploring alternative pest management strategies. For those interested in supporting bee health: Plant native flowering plants that naturally contain beneficial compounds like rutin (found in buckwheat, citrus, and other plants) to provide bees with natural protective nutrition.
  • Long-term tracking could include: (1) Monitoring bee population health in areas with different pesticide use levels; (2) Tracking which plants are flowering in bee-friendly gardens to ensure diverse nutrition; (3) Recording any changes in local bee activity or health after reducing pesticide use; (4) Documenting which native plants are most attractive to bees and most abundant in the area.

This research is a laboratory study on honey bees and should not be interpreted as medical advice for humans. While the findings suggest that imidacloprid may harm bee health and that rutin shows protective potential, this is early-stage research conducted under controlled conditions. Real-world effectiveness may differ. Anyone considering changes to pesticide use should consult with agricultural experts, local extension services, or environmental specialists. This research does not provide guidance for treating sick bees or managing bee colonies—consult a veterinarian or experienced beekeeper for those purposes. The protective effects of rutin shown in this study were observed in laboratory conditions and have not been proven effective in natural bee colonies or as a practical intervention.