Scientists tested different types of food for a tiny predatory bug called Amblyseius swirskii, which farmers use to control crop pests naturally. The researchers fed these bugs four different types of storage mites and a special dry diet mix, then tracked how well the bugs grew, reproduced, and survived over many generations. They found that one specific mite species called Carpoglyphus lactis was the best food choice, helping the bugs reproduce more successfully and stay healthy for many generations. This research helps farmers and bug-breeding facilities produce more of these helpful predatory bugs efficiently and affordably.
The Quick Take
- What they studied: Which type of food helps a tiny predatory bug (used to control crop pests) grow best and reproduce the most over many generations
- Who participated: Laboratory experiments with Amblyseius swirskii bugs fed different types of mites and artificial diet under controlled conditions, tested across 20 consecutive generations
- Key finding: Carpoglyphus lactis mites were the best food source, producing the most baby bugs and keeping populations stable for 20 generations, while other mite types produced fewer offspring or couldn’t sustain the population
- What it means for you: If you work in agriculture or pest control, this research suggests using Carpoglyphus lactis mites as food when raising predatory bugs for natural pest control is more effective and cost-efficient than other options
The Research Details
Scientists conducted controlled laboratory experiments where they fed the same type of predatory bug (Amblyseius swirskii) five different food options: four different species of storage mites, one mixed-mite treatment, and one artificial dry diet made from wheat bran, yeast, dog food, cat food, pollen, and vitamins. They carefully measured how fast the bugs developed, how many babies each bug produced, and how long they lived. For the two most promising food sources, they continued the experiment for 20 generations (many months) to see if the bugs stayed healthy and reproduced well over a long time period.
The researchers kept all conditions the same for each group—same temperature, humidity, and light—so the only difference was the food. This controlled approach helps ensure that any differences in bug performance came from the food itself, not from other factors. They used mathematical formulas to calculate important measurements like how many babies each bug produced and how fast the population could grow.
This research matters because farmers and pest-control companies need to raise millions of these tiny predatory bugs to use as natural pest control. If scientists can figure out the cheapest and easiest food to feed these bugs while keeping them healthy and productive, it makes natural pest control more practical and affordable. Testing over 20 generations is important because it shows whether the bugs stay healthy long-term, not just for a few weeks.
This study was published in the Journal of Economic Entomology, a respected scientific journal focused on practical pest management. The researchers used standardized laboratory methods and measured multiple important factors (growth, reproduction, survival) rather than just one outcome. Testing across 20 generations strengthens the findings by showing long-term stability. However, the study was conducted only in laboratory conditions, so results in real farm environments might differ. The specific sample sizes for individual experiments weren’t provided in the abstract, which limits our ability to assess statistical power.
What the Results Show
Carpoglyphus lactis mites proved to be the best food source for the predatory bugs. Bugs fed this mite species had the highest reproduction rates, produced the most offspring, and maintained stable, healthy populations across all 20 generations tested. This means farmers could reliably use this food source without worrying about the bug population declining over time.
Typrophagus putrescentiae mites were the least effective food among the options that allowed bugs to complete their full life cycle. While bugs could survive and reproduce on this food, they produced fewer offspring compared to Carpoglyphus lactis. Rhizoglyphus robini mites were even worse—bugs couldn’t survive past an early developmental stage when fed only this species.
The mixed-prey treatment (combining two mite species) didn’t improve results compared to using Carpoglyphus lactis alone, suggesting that combining foods doesn’t provide additional benefits. The artificial dry diet resulted in noticeably reduced reproduction and survival compared to all mite-based foods, indicating that living prey is significantly better than the artificial substitute tested.
The research showed that prey identity (which type of food) had a major impact on both short-term performance (how quickly bugs grew and reproduced) and long-term stability (whether populations remained healthy for many generations). This demonstrates that food choice affects not just immediate success but also the long-term viability of breeding colonies. The fact that Carpoglyphus lactis maintained consistent performance across 20 generations suggests this food source is reliable for large-scale production systems.
This research builds on previous work showing that different prey species affect predatory bug performance differently. The study confirms and extends earlier findings by testing multiple mite species systematically and, importantly, by evaluating long-term stability across many generations. The finding that artificial diets underperform compared to living prey aligns with general knowledge that natural food sources often work better than artificial substitutes for predatory insects.
The study was conducted entirely in laboratory conditions with controlled temperature, humidity, and light. Real farm environments have variable conditions that might affect results differently. The abstract doesn’t specify exact sample sizes for each experiment, making it difficult to assess how confident we should be in the findings. The research focused only on one predatory bug species, so results may not apply to other beneficial insects. The artificial diet tested was only one formulation; different recipes might perform better or worse. Additionally, the cost and availability of different mite species weren’t discussed, which would be important for practical farm applications.
The Bottom Line
For pest-control facilities and farmers raising Amblyseius swirskii bugs: Use Carpoglyphus lactis mites as the primary food source (High confidence). This choice is supported by strong evidence showing superior reproduction and long-term stability. Avoid Rhizoglyphus robini mites as a sole food source (High confidence) since bugs cannot survive on them. Consider Typrophagus putrescentiae only if Carpoglyphus lactis is unavailable, understanding that reproduction will be lower (Moderate confidence). Don’t rely on artificial dry diets as a primary food source (Moderate confidence), though they might work as occasional supplements.
This research is most relevant to: Commercial insectaries and pest-control companies that breed predatory bugs for sale, farmers using biological pest control programs, agricultural extension services advising farmers on pest management, and researchers developing sustainable agriculture practices. General consumers don’t need to apply these findings directly, but they may benefit indirectly through more affordable and effective natural pest control products.
Results from feeding predatory bugs Carpoglyphus lactis should be noticeable within 2-4 weeks (one generation cycle), with improved population stability becoming clear over 2-3 months. Long-term benefits (stable, productive colonies) develop over several months to a year of continuous breeding.
Want to Apply This Research?
- If managing a bug-breeding facility: Track weekly measurements of egg production per female bug, nymph survival rate to adulthood, and time from egg to adult. Record which mite species is being used as food and compare production metrics across different food sources over 8-12 week periods.
- For pest-control professionals: Switch to Carpoglyphus lactis mites as the standard food source for Amblyseius swirskii colonies. Document the change and monitor production metrics for 4-6 weeks to confirm improved results. Set up a simple tracking system comparing bug population growth and reproduction rates before and after the change.
- Establish a monthly tracking system that records: number of bugs produced per breeding unit, percentage of bugs reaching adulthood, average number of eggs per female, and overall colony health. Compare these metrics monthly to establish baseline performance with the new food source and identify any declining trends that might indicate problems.
This research describes laboratory findings about feeding predatory bugs used in pest control. These results apply to controlled breeding conditions and may not directly translate to field conditions on farms. Before implementing changes to pest-control programs, consult with local agricultural extension services or pest-management professionals who understand your specific crops and environment. This research does not provide medical or health advice. If you have questions about pesticide use or pest control on your property, contact your local agricultural department or a licensed pest-control professional.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.