Rumina decollata
A Mediterranean snail with a tall, cone-shaped shell whose tip breaks off as it grows. It hunts other snails and slugs, the young brown garden snail above all, and is used in southern California citrus groves, gardens and landscapes. UC IPM says it can give very effective control, but it takes 4–10 years to bring brown snails down to insignificant levels. Two limits decide whether it is an option at all. In California it can be released legally only in Fresno, Imperial, Kern, Los Angeles, Madera, Orange, Riverside, Santa Barbara, San Bernardino, San Diego, Ventura and Tulare counties. It is also a generalist predator of many snail species, and UC IPM warns against releasing it in or near natural areas because of the danger to endangered native snails.
At a glance
- Mode
- Predatory snail — hunts snails and slugs
- Rate
- 3–5 per shrub, or ~100 per 1,000 sq ft
- Shell
- Cone-shaped, up to 40–45 mm, tip broken off
- Speed
- 4–10 years to insignificant levels (UC IPM)
- Legal
- 12 California counties only
- Setting
- Irrigated shrubs, ground covers, citrus
How it works
The decollate snail is a predator of snails and slugs, the brown garden snail above all (UC IPM). The University of Florida calls it an effective predator of half-grown brown snails, and suppliers say it eats their eggs as well. It hunts at night and in overcast or rainy weather, and spends the day in leaf litter or the top inch or so of soil. It is not strictly a meat-eater. UC IPM says it also feeds on seedlings, leaves in contact with the soil and fallen, bruised fruit, although it is less of a problem than the brown snail and has not been seen eating citrus leaves or sound fruit. The Texas Invasive Species Institute warns that it turns to plants when prey runs out.
It breeds slowly, which is why control takes so long. UC IPM gives about 10 months from hatching to breeding. Each snail then lays about 200 eggs a year and up to 500 in its life, and the eggs hatch in 10 to 45 days. The population has to build before it can bring the brown snail down: UC IPM puts that at 4–10 years to reach insignificant levels, and one supplier says up to 2 years for a heavy infestation. The shell makes it easy to recognise. It is pinkish brown, narrow and up to about 40–45 mm (1⅗–1¾ in) long (UC IPM gives 40 mm, the University of Florida 45 mm), and the tip breaks off as it grows, so older snails keep only four to seven whorls.
Is it established?
Success is measured in seasons. What you are looking for is fewer brown snails, especially small ones, and decollate snails of several sizes, which show that they are breeding.
- FIRST NIGHTSDecollates out on damp soil after watering, then burrowing in by day
- WEEKSA supplier says it takes a few weeks for a noticeable effect on the brown snails
- ~10 MONTHSYoung decollates hatched on site reach breeding age (UC IPM: about 10 months), so snails of several sizes appear
- YEARS 2–10Brown snails fall towards insignificant numbers (UC IPM: 4–10 years)
Release & handling
Decollates arrive dormant, sealed into their shells for the journey. Suppliers say to wake them by running cool water over them and then leaving them in a shady spot until they come out. Release them in the late afternoon or evening onto ground that has been watered, under irrigated perennial shrubs or ground cover with plenty of organic matter.
Rinse, then shade
Run cool water over them for 2–3 minutes, drain, and leave covered in shade for 20–30 minutes until they emerge. Do not leave them sitting in water.
Evening, damp ground
Water the area first. Put 3–5 under each shrub or in groups where brown snails shelter.
No snail bait
Bait kills decollates too. Suppliers advise 3–4 weeks without bait before release; do not bait afterwards.
Keep it damp
Keep the release site moist, and hand-pick large brown snails: decollates take the young ones.
Pesticide sensitivity
UC IPM says snail baits kill decollate snails as well as brown snails, and advises against releasing them where poison baits are used. No source we found exempts iron phosphate, so use no bait where they have been released. Check a product →
When to choose something else
Decollate snails are a slow, long-term control, and release is restricted: in California to 12 counties, and suppliers say to Arizona, New Mexico and Texas elsewhere. Choose something else when:
- You are in California outside the 12 counties where release is legal, or in a state where it is restricted. Use the hand-picking, trapping and banding methods on the snails page
- The garden is near a natural area, creek or wild land. UC IPM warns against release there because of the danger to endangered native snails
- You need the damage stopped this season. UC IPM puts control at 4–10 years; hand-pick and trap instead
- You are baiting, or plan to. Bait kills decollates as well as brown snails
- The problem is slugs. Decollates will eat them, but they are sold and studied against the brown garden snail
Where to buy
Suppliers listed alphabetically, not ranked. helpfulbugs takes no commission and does not sell snails. All three listings below were out of stock when we checked on 22 September 2026, and suppliers restrict where they ship. Check with your county agricultural office before you order.
- BuglogicalPack sizes not listed (out of stock)NOT CA NORTH OF TEHACHAPIS
- Nature's Good Guys50 / 100 / 1 gallon (~2,500)AZ · NM · TX · LISTED CA COUNTIES
- Tip Top Bio-Control50 / 100 (cup or pouch)AZ · NM · TX · LISTED CA COUNTIES
Rumina decollata by target
Rate and timing differ by what you are releasing it against. Each page below is the program for one pest.