Central Life Sciences
Altosid Pro-G Mosquito Larvicide Granules
Larvicide · EPA-registered pesticide
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Pros
- Kills 88-98% of larvae in the water you treat, before they can bite
- Target-specific, safe for fish, pets, birds, bees, and wildlife
- EPA-registered biopesticide
- Active ingredient concentration disclosed
Cons
- Source control only, so it lowers the future mosquito population rather than stopping tonight's bites
- Works only where you can reach standing water, and needs replacing about every 30 days
The full review
Granular larvicide from Central Life Sciences built on (S)-methoprene, an insect growth regulator rather than a conventional toxic pesticide. Instead of poisoning larvae outright, it interrupts their development so exposed larvae reach the pupal stage and die before they can emerge as biting adults. One 2.5-pound container treats up to about 5,445 square feet and provides up to 30 days of control per application. It is marketed as having no adverse effect on humans, animals, fish, or vegetation at label rates, though methoprene can affect some estuarine crustaceans. At a consumer-scale price for 2.5 pounds, it is a source-control product for breeding sites rather than a personal repellent.
Scorecard
Expand any pillar to see exactly why it scored what it did.
Effectiveness45%82Its job is to shrink your yard's mosquito population, and it does it well: it kills roughly 88-98% of the mosquito larvae in the standing water you treat, over about 5445 sq ft of water per unit. It stops larvae before they become biting adults, thinning the next generation of mosquitoes around a breeding site. Scored on that larval-control efficacy, discounted only because it reaches the standing water you can find and treat and not the mosquitoes breeding elsewhere (lower confidence).
Its job is to shrink your yard's mosquito population, and it does it well: it kills roughly 88-98% of the mosquito larvae in the standing water you treat, over about 5445 sq ft of water per unit. It stops larvae before they become biting adults, thinning the next generation of mosquitoes around a breeding site. Scored on that larval-control efficacy, discounted only because it reaches the standing water you can find and treat and not the mosquitoes breeding elsewhere (lower confidence).
Evidence & honest claims25%66S-methoprene is well-supported by published evidence, weighted by how close its concentration is to the studied effective dose (base 56). Of 4 marketing claims audited: 2 strong, 2 moderate, 0 weak, 0 unsupported (+10).
S-methoprene is well-supported by published evidence, weighted by how close its concentration is to the studied effective dose (base 56). Of 4 marketing claims audited: 2 strong, 2 moderate, 0 weak, 0 unsupported (+10).
Safety15%84This is a biological larvicide. Its active (Bti) targets only mosquito, black fly, and fungus gnat larvae and is documented safe for fish, pets, birds, bees, and other wildlife by the EPA, WHO, and CDC. It is designed to be placed directly in standing water, so there is no dermal exposure and negligible non-target hazard. A non-Bti active here carries some aquatic caution.
This is a biological larvicide. Its active (Bti) targets only mosquito, black fly, and fungus gnat larvae and is documented safe for fish, pets, birds, bees, and other wildlife by the EPA, WHO, and CDC. It is designed to be placed directly in standing water, so there is no dermal exposure and negligible non-target hazard. A non-Bti active here carries some aquatic caution.
Transparency15%85This product names its active ingredient (+30); discloses the strength of every active (+35); publishes a concrete coverage figure (+20).
This product names its active ingredient (+30); discloses the strength of every active (+35); publishes a concrete coverage figure (+20).
Every pillar is scored from published rules. Read how we score.
Larval control
This is a larvicide: it kills mosquito larvae in the standing water you treat, stopping them before they become biting adults. It lowers the local population over time but does not stop bites from mosquitoes bred elsewhere.
Mosquitoes
EstimatedModerate- Treated water
- ~5445 sq ft of water
- Larvae killed
- 88-98%
The band shown reflects larval control at the breeding site, not on-the-spot protection. (S)-methoprene is an insect growth regulator that stops exposed larvae from emerging as biting adults, and one application provides up to about 30 days of control, though real-world persistence varies with water conditions and reflooding. This is source control that kills the next generation in the standing water where mosquitoes breed rather than repelling the adults already flying. Pair it with dumping standing water where you can and with a skin repellent for immediate protection.
Ingredient disclosure
This product names its active ingredient (+30); discloses the strength of every active (+35); publishes a concrete coverage figure (+20).
Only active ingredients are disclosed. The full ingredient list (inerts/carriers) is not published, so this may not be the complete formula.
- S-methopreneActive
Active larvicide · 1.5%
Claims audit
What the marketing says, versus what the evidence supports.
“Releases effective levels of methoprene for up to 30 days after application.”
DurationModerateManufacturer and label duration; field persistence varies with water conditions and reflooding.
“Insect growth regulator prevents adult mosquito emergence.”
EfficacyStrongMechanism is well established in the literature and on the EPA-registered label.
“Will not cause adverse effects in humans, animals, fish, or vegetation when used per label.”
SafetyModerateBroadly supported by EPA review at use rates, though methoprene can be toxic to some estuarine crustaceans.
“Larvae develop to the pupal stage, then die before becoming biting adults.”
EfficacyStrongAccurate description of the growth-regulator mode of action.
Safe around dogs & cats?
Worst case from this product’s active ingredients. Do not apply this or any human repellent to your pet.
Not veterinary advice. Full guide to repellents around pets →