Alpine WSG is a water-soluble granule insecticide that works well against both German and American cockroaches, including populations that have developed resistance to common pyrethroid sprays. Its active ingredient, dinotefuran, belongs to the neonicotinoid class and kills roaches through a different mechanism than most over-the-counter sprays, which is why pest control professionals and DIY users turn to it when other products stop working.
How Alpine WSG Kills Roaches
Dinotefuran targets the nerve receptors that control muscle movement in insects. It forces open ion channels along the cockroach’s nerve-muscle connections, and because insects lack the enzyme needed to break down the compound, those channels stay locked open. Real nerve signals can’t get through. The result is progressive muscle paralysis followed by death.
This matters practically because it’s a completely different pathway than pyrethroids (the active ingredient in most hardware-store roach sprays). University of Kentucky research on field-collected German cockroach populations found that even populations showing up to 10-fold resistance to dinotefuran in lab conditions still died at high rates when exposed to Alpine WSG at label rates. In residual exposure tests, every population tested reached 90% or greater mortality within 48 hours after just 60 minutes of contact with treated surfaces. There was no meaningful statistical relationship between a population’s measured dinotefuran resistance level and how well Alpine WSG actually performed in practice, suggesting the product’s real-world formulation overcomes the resistance levels currently seen in the field.
Mixing Rates for Cockroaches
Alpine WSG comes as dry granules that you dissolve in water. The label rate for cockroaches is 10 to 30 grams per gallon of water. Use the lower end of that range, 10 grams per gallon, for maintenance applications or lighter activity. For heavy infestations, mix up to 30 grams per gallon.
The product dissolves cleanly in water without the clumping issues you get with wettable powders. It also leaves minimal visible residue on most surfaces, which makes it practical for indoor use on dark countertops, baseboards, and appliances where a chalky film would be obvious. A standard 200-gram pouch makes between roughly 6.5 and 20 gallons of finished solution depending on your rate, so a single pouch goes a long way for apartment or home treatments.
Where and How to Apply
For German cockroaches, focus your spray on the places roaches actually live and travel. Kitchens and bathrooms are priority zones. Hit the cracks and crevices where cabinets meet walls, the gap behind the kick plate under your kitchen cabinets, around plumbing penetrations under sinks, behind and underneath the refrigerator, around the stove (especially the gap between the stove and counter), and along the edges where countertops meet the backsplash.
In bathrooms, spray behind the toilet, under the vanity, and around any gaps where pipes enter walls. Don’t neglect the areas around electrical outlets and switch plates in kitchens and bathrooms, as roaches use the voids inside walls as highways and enter rooms through these openings.
For American cockroaches (the larger, reddish-brown species), expand your treatment to include garage perimeters, utility rooms, basement edges, and around exterior door thresholds. These roaches tend to come in from outside, so treating entry points is more important than treating every kitchen crevice.
Use a pump sprayer or a smaller handheld sprayer with a pin-stream nozzle for crack-and-crevice work. You’re not soaking surfaces. A light, even application into cracks and along edges is what creates the residual barrier roaches walk through. The residue stays active on surfaces for weeks, killing roaches that cross treated areas long after the spray dries.
How Quickly It Works
Alpine WSG is not an instant knockdown product. Roaches that contact treated surfaces typically die within hours, not seconds. In university testing with Alpine gel bait (same active ingredient), the median survival time for most German cockroach populations was about 1 hour after ingestion, though one highly resistant population took up to 24 hours. With the spray applied as a residual surface treatment, the timeline depends on how much contact a roach has with the treated surface, but the 48-hour window after initial contact is when you’ll see the bulk of mortality.
If you’re treating an active infestation, expect to see dead roaches showing up over the first few days. You may also see increased roach activity initially as the product flushes them out of hiding spots. This is normal and a sign the treatment is reaching them.
Safety Around People and Pets
Alpine WSG carries a “caution” signal word, the lowest toxicity category for pesticide labeling. It’s labeled for use in sensitive environments including homes with children and pets, but with straightforward precautions.
Keep children and pets off treated surfaces until the spray has fully dried, which typically takes 30 minutes to an hour depending on ventilation and humidity. Cover fish tanks and aquariums before spraying anywhere near them, as neonicotinoids are toxic to aquatic organisms. Wear gloves and long sleeves while mixing and applying. Once the product dries, it forms an invisible residue that poses minimal contact risk to people and mammals but remains lethal to insects walking across it.
Getting the Most Out of Your Treatment
Alpine WSG works best as part of a combined approach rather than as a standalone solution for heavy infestations. Pair it with gel bait placed in the same areas you’re treating. The spray creates a residual barrier on surfaces while the bait provides an attractive food source laced with toxicant. Roaches that avoid one method often encounter the other.
Clean up food debris and fix water leaks before treating. Roaches need water more than food, so eliminating dripping faucets and standing water under sinks forces them to range farther and contact more treated surfaces. For German cockroach infestations in apartments, treat every room, not just the kitchen. These roaches spread throughout living spaces once populations grow, and untreated rooms become refuges that allow rebound.
Reapply every 2 to 4 weeks for active infestations, then shift to the lower 10 grams-per-gallon maintenance rate once you stop seeing live roaches. Residual activity diminishes over time, especially on porous surfaces or areas that get wiped down frequently, so periodic retreatment keeps the barrier intact.