How Many Hornworms Come in a Cup, and How Long Do They Last?

Cup Size and Count: The Standard

Hornworms ship in a standardized single-size format: 1 Cup containing 20–24 individual hornworms. This is the only cup size available from commercial suppliers. There are no "small," "medium," or "large" variants the way there are for other feeder insects like discoid roaches. Every cup you order contains roughly the same count and roughly the same range of sizes (hornworms in a cup are all similar ages, so they're all similar sizes too).

This standardization is actually convenient for budgeting purposes. You always know exactly what you're getting: 20–24 feeders per cup, no surprises.

Shelf Life: 1–2 Weeks

With proper storage—specifically, cool temperature between 50–55°F—a cup of hornworms remains viable for approximately 1–2 weeks. This is the realistic usable window. After that, hornworms begin to outgrow their ideal feeding size, some may enter pupation (hardening into a chrysalis), and overall viability declines.

This short shelf life is fundamentally different from other common feeders. Discoid roaches can live for weeks or months in a colony setup. Crickets can survive for several weeks. But hornworms are caterpillars in an active growth phase. Their biology is programmed toward rapid development. Accept the 1–2 week window as non-negotiable; it's a feature of their biology, not a flaw in how they're raised.

Storage Temperature Controls Longevity

The 50–55°F temperature range is specific because it dramatically slows growth and molting cycles, extending the shelf life to the full 1–2 weeks. Store hornworms warmer, and that window collapses. At room temperature (70°F+), a cup may only be viable for 3–5 days before growth and pupation accelerate past the point of usefulness.

This is why a dedicated cooler, refrigerator shelf, or basement with stable cool temperatures is essential if you plan to keep hornworms regularly. Without temperature control, shelf life becomes unreliably short.

Budgeting for a Rotation Schedule

To maintain a consistent hornworm feeding rotation without stress, you need to think about how often you feed them and how many animals you're feeding.

One animal, feeding once weekly: A single cup lasts two weeks, which covers two weekly feedings with some buffer. Order one cup every 10–12 days to maintain steady supply.

One animal, feeding twice weekly: A cup provides up to 24 hornworms. If you feed one hornworm twice a week, that cup lasts roughly 12 weeks—except it won't, because the 1–2 week shelf life cuts it off much sooner. You'd only use 2–4 hornworms from a cup before viability ends. In this scenario, you'd need to order more frequently and accept that most of the cup goes unused, or pair hornworms with other feeders so you're not relying on them as your primary diet.

Multiple animals (2–3 small feeders): With multiple animals, you can burn through a cup faster. Three small reptiles, each eating one hornworm weekly, uses 3 hornworms per week—so a 24-cup spans roughly 8 weeks, but again, the 1–2 week viability window means you'd need to order fresh cups frequently and manage timing carefully.

The Real Constraint: Not the Count, But the Shelf Life

The limiting factor for hornworm feeding isn't how many are in a cup—it's how long that cup stays viable. Twenty-four hornworms sounds like a lot until you realize the cup only lasts two weeks. If you're feeding slowly (one or two per week), you'll use only a portion of the cup before it must be discarded. This is the reality of feeding hornworms: they're a supplement, not a staple. Plan around the shelf life, not the count.

Integrating Hornworms Into Feeding Rotation

The smart approach to hornworms is to use them as part of a varied diet, not as a primary feeder. Offer one hornworm 1–3 times weekly as an appetite stimulant or hydration supplement, paired with a primary protein source like discoid roaches. In this role, a single cup every 1–2 weeks is plenty, and you're never stressed about shelf life because you're not relying entirely on that cup.

If you try to make hornworms your main protein source, the short shelf life and modest count (relative to feeding frequency) become constraining. If they're a supplement, the cup size and shelf life align nicely with typical keeper usage patterns.

Ordering Frequency and Planning

Plan to order fresh hornworms every 1–2 weeks if you feed them regularly. Don't try to stockpile multiple cups; the shelf life makes that impractical. Order fresh, use the cup promptly, and reorder before your current cup runs out or expires. This is a minor inconvenience, but it's the biological reality of the feeder.