Anything garden safe should work! This is the one i use regularly and it works great!
Garden Safe Brand Crawling Insect Killer Containing Diatomaceous Earth, 4-Pound https://www.amazon.com/dp/B004Q0DM82/ref=cm_sw_r_cp_api_glt_fabc_8QWZD1NPFC0R15HGRE5G
TO GET RID OF INSECTS IN BASEMENT:
(So you can feel safer down there...)
If you can, buy some DIATOMACEOUS EARTH. Diatomaceous earth products are registered for use against bed bugs, COCKROACHES, crickets, fleas, ticks, spiders, and many other pests.
Here's an example:
Garden Safe 93186 Insect Killer, 1-count https://www.amazon.com/dp/B004Q0DM82/ref=cm_sw_r_apan_glt_i_NC766P5AZZA2KZRF6CNS
I find it at a local shop that is REALLY inexpensive.
Sprinkle all around the sides of basement floor at the walls. This will kill the bugs down there. I'd also sprinkle where you don't walk. Insects walk through the powder. The abrasive powder creates sharp cuts and dries out the insect. It's a very easy to use and beneficial product that WORKS!
You will soon be able to face the basement without fear or discomfort. With all the other awesome suggestions, AND YOUR DOING, it's a done deal!!
Let us know how you're doing when this challenge is conquered.