I’m planning to use a dust in my attic for silverfish and in my crawl space for camel back crickets.
I think I’ve seen references in your articles to both the following:
Delta Dust: #452821
Deltamethrin Dust: #452825
Can you please what the difference is between the two?
Great question. There are many differences between these two products besides just their active ingredient. These other differences are what makes one better suited when treating certain pests or certain areas.
As a general rule, DELTAMETHRIN DUST is better suited for moist areas like crawl spaces. It's non repellent action will allow targeted insects to walk over treated areas which in turn leads to their demise. Applications will last 4-8 months and it's odorless so use in living areas is acceptable for some pests.
On the flip side there is DRIONE DUST. This dust is almost the exact opposite of the Deltamethrin dust in that it works as a desiccant stealing away vital moisture needed by most all insects. For this reason it's highly repellent to insects and they'll avoid it like the plague. This makes it a great choice for something like SILVERFISH that commonly enter living spaces from attics. Treating routes of entry like electric outlets, light fixtures, molding and other cracks where they can penetrate will prevent them from using these areas altogether after it's dusted. It's also good for attic spaces (attics are typically dry compared to crawl spaces) and in general, it will last 12 months or longer when kept dry.
In summary, Drione Dust is ideal for when you need to establish a long lasting repellent barrier through which target insects cannot enter. Better suited for dry areas, Drione can last a long time when used inside. But don't be afraid to use it's repellency action outside. It can be a strong deterrent keeping a wide range of insects out of your home. This is especially true when used in the spring under siding and roof shingles. A thorough treatment done every spring will effectively stop wasps and other pests from entering your home. Conversely, Deltamethrin is better for moist areas like crawl spaces or where you don't want to repel targeted insects.
Based on the two insects you mentioned above, I think you'll need to employ both products.
Here are direct links to the items mentioned above: