Thanks for your question.

In all honesty, I seriously doubt that if you are having issues with your vegetables, isopods are to blame. They are NOT INSECTS but are Crustaceans. They are highly beneficial for gardens. They primarily feed upon dead plant material and significantly contribute to the recycling of nutrients in the soil. They generally are active only at night. If you are seeing something during the day on your plants, it would be highly unusual and unexpected that they are isopods. There are several types of insects that look like isopods, which makes me wonder if the identification of isopods is correct. Even if isopods are present and there are problems with your vegetables, this does not necessarily mean that isopods are the culprits. See the following for further information:

https://mdc.mo.gov/discover-nature/field-guide/pillbugs-sowbugs-land-isopods

https://entomology.ca.uky.edu/ef439

https://www.smug-bug.com/post/what-do-isopods-eat

Because isopods possess a hard shell, they are largely impervious to most insecticides. In fact, if you wanted to use some chemical spray against isopods, it must be sprayed directly on them. Considering the nocturnal nature of isopods, this would mean you would be doing things at night and not during the day. If you wish to pursue the idea that isopods are the cause of your gardening problems, use a product whose label explicitly states that it is intended for isopods. Moreover, it should contain one or more of the following active ingredients: permethrin, cyfluthrin, or bifenthrin. Note these compounds are quite lethal for beneficial insect pollinators. They would be killed if they encountered the product that you are be applying. Furthermore, the use of these products may render your vegetables unsuitable for human consumption. See the following for further information:

https://ipm.ucanr.edu/mitigation/protect_beneficials.html - :~:text=Carbamates (e.g., carbaryl),,migrate in after the application.

https://growingspaces.com/get-rid-of-pill-bugs/

In short:

1). Are you sure, without any doubt, that isopods are the cause of whatever problems you are having with your vegetables?

2). Your vegetables may not improve if you focus only upon the elimination of isopods. You may be ignoring insects that are the true cause.

3). The products used for isopod elimination will be highly detrimental for many types of beneficial insect pollinators.

4). It would be extremely useful in our getting to the bottom of things for you to submit a picture to us of whatever critter you think is negatively impacting your vegetables.

Good luck. Please get back to us with any additional, related questions.