Black Soldier Fly Larvae vs Mealworms: Which Wins for Feed?

Quick Answer

Black soldier fly (BSF) larvae, Hermetia illucens, generally offer a faster production cycle, higher natural calcium content, and a more saturated fat profile dominated by lauric acid. Mealworms, Tenebrio molitor, tend to grow more slowly but convert feed with lower maintenance losses, carry a more unsaturated fatty acid profile, and have a longer track record in pet food approvals. Neither is universally superior; the right choice depends on target species, chitin tolerance, regulatory scope, and substrate availability.

Key Takeaways

• Protein and fat overlap: on a dry matter basis, BSF larvae typically run 30–45% crude protein and 25–40% fat, while mealworms range 20–50% crude protein and 20–40% fat — the ranges are close, but processing method (whole, defatted, partially defatted) changes the numbers more than species does.

• Fat quality differs: BSF larvae fat is dominated by lauric acid (a saturated medium-chain fatty acid), while mealworm fat leans toward oleic and linoleic acid, closer to a vegetable oil profile.

• Chitin is comparable, not a tiebreaker: both insects fall in a similar 3–9% chitin range on a dry matter basis, so digestibility concerns apply to both, not just one.

• Growth speed favors BSF larvae: BSF larvae can reach harvest weight in as little as two weeks, versus 60–120 days for mealworms, which affects production cost and supply responsiveness.

• Regulatory scope differs by species and species-of-use: both are covered under EU insect PAP rules, but their approval history in specific animal categories (aquafeed, poultry, swine, pet food) is not identical.

• Calcium content favors BSF larvae: the mineralized BSF exoskeleton generally supplies more calcium than mealworms, which is relevant for poultry and reptile diets that need calcium support.

Table of Contents

1. What Are Black Soldier Fly Larvae and Mealworms

2. Nutritional Composition Compared

3. Fatty Acid Profile and Fat Quality

4. Amino Acid Profile and Protein Quality

5. Calcium, Phosphorus, and Mineral Content

6. Chitin Content and Digestibility

7. Rearing Substrates and Feed Conversion Efficiency

8. Regulatory Status in the EU and US

9. Application by Animal Species

10. Sourcing and Supply Chain Considerations

11. Buyer Checklist for Procurement Teams

12. Which One Should You Choose

13. Frequently Asked Questions

14. References

What Are Black Soldier Fly Larvae and Mealworms

Black soldier fly larvae are the larval stage of Hermetia illucens, a non-pest fly native to the Neotropics and now farmed globally. The larvae are reared on organic substrates, harvested before the pupal stage, then dried and either sold whole, ground into powder, defatted into a higher-protein meal, or pressed for black soldier fly larvae oil.

Mealworms are the larval stage of Tenebrio molitor, a darkling beetle traditionally reared on grain-based substrates such as wheat bran. Commercial mealworm products follow a similar processing path: whole dried larvae, ground mealworm protein powder, defatted meal, or mealworm oil.

Both insects are classified as insect-derived processed animal proteins ("insect PAPs") under EU feed law, and both appear on the same list of species authorized for use in aquaculture, poultry, and pig feed.

Definition Box

Nutritional Composition Compared

On a dry matter basis, the two insects occupy overlapping nutritional territory, but their ranges are driven by different factors. BSF larvae protein and fat content shift substantially across the larval life cycle: one life-cycle study found crude fat climbing to about 28% by day 14 of larval development while crude protein dipped to a low of roughly 38% in the same window, before protein rose again through the pupal stages. Mealworm composition is less life-cycle-driven and more substrate-driven, since mealworms are typically harvested at a more standardized larval size.

A recent comparative review in a veterinary science journal placed both species side by side on a dry matter basis:

Two practical points follow from this table. First, the raw ranges overlap enough that species alone does not predict which ingredient has more protein — processing method matters more. A partially defatted BSF meal can reach crude protein in the high 50s percent range, well above a whole-fat mealworm product, simply because removing oil concentrates the remaining protein fraction. Second, chitin content is essentially comparable between the two insects, so buyers should not treat chitin as a reason to prefer one species over the other; it is a processing and inclusion-rate issue for both.

Procurement teams should request a certificate of analysis (CoA) for each specific lot rather than relying on published ranges, since substrate, harvest age, and drying method all shift the final numbers for both whole dried mealworms and dried black soldier fly larvae.

Fatty Acid Profile and Fat Quality

The two insects diverge more clearly on fat composition than on total fat percentage. BSF larvae fat is unusually rich in lauric acid, a medium-chain saturated fatty acid also found in coconut oil, which some research associates with antimicrobial properties in the gut. Mealworm fat, by contrast, is closer to a conventional vegetable oil profile, weighted toward oleic and linoleic acid — the same unsaturated fatty acids common in sunflower or soybean oil.

This distinction matters for formulation. A feed that already supplies ample unsaturated fat from soybean or canola meal may benefit from the differentiated lauric-acid profile of black soldier fly larvae oil, while a diet needing standard unsaturated fatty acid contribution may find mealworm oil a closer functional match to existing vegetable oil inclusions. Fatty acid composition in both species also shifts with the rearing substrate, so lot-level fatty acid testing is advisable for aquafeed formulations where lipid profile affects fillet quality.

Amino Acid Profile and Protein Quality

Both insects supply a full complement of essential amino acids, and published comparisons describe the amino acid profile of BSF larvae as comparable to, or in some indispensable amino acids exceeding, soybean meal. Lysine and methionine levels in BSF larvae have been described as comparable to meat-based protein sources. Mealworm protein has independently demonstrated high digestibility in controlled trials — a six-month feeding study supporting a US ingredient approval documented protein digestibility exceeding 80% at inclusion levels up to 30% of the diet.

In practice, neither species has a decisive amino acid advantage over the other for most livestock and pet food formulations; both compare favorably to fishmeal and soybean meal on lysine, though methionine and cysteine levels in either ingredient may still require supplementation depending on the target diet's overall amino acid balance.

Calcium, Phosphorus, and Mineral Content

This is one of the more consistent differences between the two insects. BSF larvae carry a mineralized exoskeleton that is naturally higher in calcium than most insect proteins, with published values for BSF products commonly falling in a range that is an order of magnitude above typical mealworm calcium content, depending on whether the product is whole larvae, meal, or defatted meal. Mealworms are comparatively calcium-poor and phosphorus-heavy relative to BSF larvae, a pattern documented across multiple nutritional composition studies of farmed insects.

For formulations where calcium supply is a design constraint — poultry layer feed, reptile and exotic pet diets, or any ration where calcium-to-phosphorus balance is tightly managed — this difference can reduce the amount of external calcium supplementation needed when BSF-based ingredients are used, though it does not eliminate the need for a full mineral audit of the finished ration.

Chitin Content and Digestibility

Chitin sits at 3–9% of dry matter in both insects, and the digestibility research on chitin is more nuanced than a simple "chitin is bad" framing suggests. Chitin has documented immunostimulant and gut-microbiota effects in some species, and moderate levels have been associated with bacteriostatic activity against certain gram-negative pathogens. At the same time, multiple studies link higher chitin inclusion to reduced protein and dry matter digestibility, particularly in aquafeed applications; one rainbow trout study found that BSF larvae meal at a 40% inclusion rate, corresponding to roughly 2 grams of chitin per 100 grams of dry matter, reduced protein digestibility without a measurable effect on growth.

Poultry studies report a similar pattern: BSF larvae inclusion up to roughly 10% in broiler starter diets has been associated with improved live weight and feed intake, an effect partly attributed to improved diet palatability, while higher inclusion levels require closer monitoring of nutrient digestibility. Because chitin content and its digestibility impact are broadly similar between BSF larvae and mealworms, the practical takeaway for procurement is the same for both ingredients: validate the maximum inclusion rate for the target species through trial data or supplier documentation rather than assuming a fixed percentage applies universally.

Rearing Substrates and Feed Conversion Efficiency

BSF larvae and mealworms are typically reared on different substrate types, which affects both cost structure and regulatory framing. BSF larvae are commonly reared on vegetal by-products and other EU-permitted "feed grade" materials; municipal food waste is not currently permitted as an insect-rearing substrate for feed use in the EU due to safety and traceability concerns, even though BSF larvae are biologically capable of processing a wide range of organic material. Mealworms are conventionally reared on cereal-based substrates such as wheat bran, though research substrates for mealworms increasingly include agricultural by-products as well.

On feed efficiency, a comparative metabolic study reared both species on the same set of food and agricultural by-products and found that BSF larvae converted 33–56% of assimilated feed into growth (measured in carbon equivalents), compared with 16–40% for mealworms. Mealworms showed an advantage in lower maintenance energy losses, but BSF larvae showed higher specific growth rates, faster feed assimilation, and a shorter development period overall. BSF larvae can reach harvest weight in as little as two weeks under favorable conditions, while mealworms typically take 60 to 120 days to reach a comparable dry-weight target. This growth-speed gap is one of the more operationally significant differences between the two insects for producers scaling output.

Regulatory Status in the EU and US

Regulatory coverage for the two species is similar in scope but distinct in approval history.

European Union. Commission Regulation (EU) 2017/893 first authorized processed animal protein from seven insect species, including both Hermetia illucens and Tenebrio molitor, for use in aquaculture feed starting July 2017. Commission Regulation (EU) 2021/1372 extended authorization for the same species list to poultry and pig feed from September 2021, reasoning that poultry are naturally insectivorous and pigs are omnivorous. A later amendment added silkworm as an eighth authorized species. Insect PAPs reared for EU feed use must come from feedstock composed of feed-grade materials; catering and food waste remain excluded from permitted substrates for this purpose.

United States. The two species have followed different AAFCO approval paths. Dried black soldier fly larvae hold an official AAFCO ingredient definition (T60.117) covering use in finfish, poultry, and swine feed, and in adult dog food, with a related definition (T33.29) for black soldier fly larvae oil covering swine and finfish feed plus adult dog and cat food. Defatted mealworm (Tenebrio molitor) meal received AAFCO approval for use in adult dog food, following a favorable FDA scientific opinion and a supporting feeding trial. As of this writing, AAFCO has not extended a mealworm ingredient definition to poultry, swine, or aquafeed applications in the way it has for BSF larvae, so buyers formulating outside the pet food category should confirm current ingredient definitions for the specific species and animal category before finalizing a formulation.

Because AAFCO definitions and EU annex lists are amended periodically, procurement and regulatory teams should verify the current definition text and any state-level adoption status directly with AAFCO or the relevant EU implementing regulation before finalizing label claims.

Application by Species

Poultry. Both BSF larvae and mealworms have shown positive palatability and growth effects at moderate inclusion levels in broiler diets, with BSF larvae additionally offering a calcium contribution that can reduce external limestone or calcium supplementation needs.

Aquaculture. Insect meal, including both species, has been studied as a partial fishmeal replacement in a range of species. Reported replacement levels vary substantially by fish species and trial design, with mealworm meal cited in some tilapia and catfish trials as capable of replacing a meaningful share of dietary fishmeal, subject to chitin-related digestibility limits at higher inclusion rates. Formulators should treat any specific replacement percentage as trial-specific rather than universal, and validate inclusion levels against their own species and life stage.

Pet food. Mealworm meal currently carries a specific US AAFCO approval for adult dog food, while dried black soldier fly larvae carry a broader existing AAFCO definition that already includes adult dog food alongside finfish, poultry, and swine use. Both defatted BSF protein meal and defatted mealworm protein powder are used in novel-protein pet food formulations aimed at animals with conventional protein sensitivities.

Swine. Both species fall under the EU's 2021 authorization for pig feed, and BSF larvae additionally carry a US ingredient definition covering swine use; mealworm's US approval to date is limited to the adult dog food category.

Sourcing and Supply Chain Considerations

The insect protein sector has seen real financial volatility on both the mealworm and BSF sides, which is a legitimate procurement consideration rather than a species quality issue. A prominent European mealworm producer entered judicial liquidation in December 2025 after failing to secure continuation financing, following an extended period of court-supervised restructuring. On the BSF side, at least one European producer's holding company entered a court-supervised safeguard procedure in early 2025 amid sector-wide financing pressure. These events reflect the capital intensity and still-maturing unit economics of industrial insect farming broadly, not a structural weakness specific to either Hermetia illucens or Tenebrio molitor as a feed ingredient.

For buyers, the practical implication is the same regardless of which species is under consideration: qualify suppliers on production continuity and financial standing, not species alone, and avoid single-sourcing a formulation-critical ingredient without a documented backup supplier.

Buyer Checklist for Procurement Teams

• Request a current certificate of analysis (CoA) for the specific lot, not a generic species-level spec sheet, covering crude protein, crude fat, moisture, and ash at minimum.

• Confirm whether the product is whole, partially defatted, or fully defatted, since this changes protein concentration, fat content, and price per protein unit.

• Ask for chitin content or fiber data if the target species (especially aquafeed or young poultry) is chitin-sensitive at your planned inclusion rate.

• Verify the rearing substrate category and confirm it meets the feed-grade material requirements applicable in your target market.

• Confirm the ingredient's current regulatory status for your specific target animal category (aquafeed, poultry, swine, or pet food), since approval scope differs between BSF larvae and mealworms.

• Ask about microbial and heavy metal testing protocols, since substrate quality directly affects contaminant risk in both insect species.

• Assess supplier financial stability and production redundancy, given recent volatility in the insect protein sector.

• Compare landed cost per unit of digestible protein, not just price per kilogram, when comparing BSF and mealworm products from different suppliers.

Which One Should You Choose

There is no universal winner between black soldier fly larvae and mealworms; the better fit depends on the formulation goal.

Choose black soldier fly larvae or BSF larvae powder when calcium contribution matters, when a faster and potentially more cost-stable production cycle is a sourcing priority, or when the lauric-acid fat profile fits the target diet's fatty acid design.

Choose mealworms or bulk dried mealworms when a more unsaturated, vegetable-oil-like fat profile is preferred, when the application is pet food and the defatted meal's documented high digestibility is a priority, or when an established grain-based substrate supply chain is operationally simpler for your supplier network.

In many commercial formulations, the two ingredients are not mutually exclusive. Blending bulk BSF larvae with mealworm-based ingredients can balance calcium contribution against fatty acid profile, provided the combined chitin load stays within validated limits for the target species.

Frequently Asked Questions

Is black soldier fly larvae or mealworm higher in protein?

Neither has a fixed advantage. Both range roughly 20–50% crude protein on a dry matter basis depending on species-specific variation and, more significantly, on whether the product is whole, defatted, or partially defatted. Always compare a certificate of analysis rather than published averages.

Which has more fat, black soldier fly larvae or mealworms?

Total fat content overlaps in a similar 20–40% range for both, but the fat composition differs: BSF larvae fat is dominated by lauric acid, a saturated medium-chain fatty acid, while mealworm fat leans toward the unsaturated oleic and linoleic acids.

Do black soldier fly larvae or mealworms contain more chitin?

Both fall in a comparable 3–9% chitin range on a dry matter basis. Chitin is not a meaningful differentiator between the two species; digestibility management applies equally to both.

Are mealworms or black soldier fly larvae approved for poultry feed in the EU?

Both species are included on the list of insect PAPs authorized for poultry and pig feed under Commission Regulation (EU) 2021/1372, provided they are reared on permitted feed-grade substrates.

Which insect protein is approved for pet food in the US?

Dried black soldier fly larvae carry an AAFCO ingredient definition that already covers adult dog food alongside finfish, poultry, and swine use. Defatted mealworm meal separately holds its own AAFCO approval specifically for adult dog food. Neither species currently holds a general AAFCO approval for adult cat food, though BSF larvae oil's definition does extend to adult cat food.

Can black soldier fly larvae and mealworms be used together in the same feed formulation?

Yes. Many commercial diets combine multiple insect protein sources to balance amino acid, fatty acid, and mineral profiles, as long as the combined inclusion rate respects the chitin and fat tolerance of the target animal species.

References

• Commission Regulation (EU) 2021/1372 of 17 August 2021, EUR-Lex: https://eur-lex.europa.eu/eli/reg/2021/1372/oj/eng

• Commission Regulation (EU) 2017/893 of 24 May 2017, EUR-Lex: https://eur-lex.europa.eu/eli/reg/2017/893/oj/eng

• Association of American Feed Control Officials, Ingredient Definitions Committee (Dried Black Soldier Fly Larvae T60.117 and Black Soldier Fly Larvae Oil T33.29): https://www.aafco.org/wp-content/uploads/2024/11/5.-IDC-Annual.pdf

• Li, Q. et al., "Dynamic changes of nutrient composition throughout the entire life cycle of black soldier fly," PMC, National Center for Biotechnology Information: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5552164/

• Comparative nutritional composition of farmed insect species (black soldier fly larvae and yellow mealworm), Acta Veterinaria Hungarica: https://real.mtak.hu/239137/1/004-article-p139.pdf

• Chitin effects on poultry nutrition and immune function, Animals (MDPI): https://www2.mdpi.com/2076-2615/9/6/307

• Metabolic performance comparison of mealworms and black soldier fly larvae reared on food and agricultural by-products, PMC, National Center for Biotechnology Information: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11759143/