Posting this from a conversation Emily and I was having about the pillbugs and wood chip mulch systems, thought it would be better to post here to share.
Pillbugs are prolific, giving birth to 30-80 young per brood round. Here in Texas for an example they can have up to three rounds a year, it is possible to both have wet hot summers and dry hot summers here. Adults are long lived, approximately two years.
It is a very familiar and common inhabitant of mulched gardens and flower beds. In most of the year they can be harmless as they are content to feed on decaying vegetable matter in and on the soil. Don’t have a supply of decaying vegetable matter? You’ll be having some hungry pill bugs eager to eat just about anything you plant that they can get to. Feedings take place mostly in the evening or at night. During the day they like to hide from the heat and the dry anywhere they can. Under flowers and plants that are shading the ground, under mulch or leaves, in cracks in brick work used for rain drainage, under dog houses, under flower pots, under grass clippings–and if you cleaned all of that immaculately off your ground including every single fallen leaf, they will also burrow down a few inches under the ground to escape the dry and the heat only to reemerge at night. You’ll also have to stop irrigating the ground to make sure there is no moisture to attract them.
Control
Natural - Frogs, toads, lizards, small animals eat them. But when you have a lot of rains this stimulates the next brooding so you get population increases. Natural methods of control will lag before catching up and reaching a better equilibrium.
I don’t want Natural - Pesticide sprays, granules and baits can help control, notice control and not eliminate pillbugs outside. Permethrin insecticide is more effective than acephate (Orthene) or carbaryl (Sevin) sprays. Other pyrethroid insecticides, such as cyfluthrin, esfenvalerate or lambda-cyhalothrin should also provide control. Always follow label directions, especially when applying slug and snail baits, as these products can be harmful to children and pets if misapplied. Safer organic baits containing iron phosphate and Spinosad are also shown to effect control on pillbugs.
OK I don’t want to use those, but I also don’t want to wait for predators in the system to arrive to build up numbers - Barrier systems such as diatomaceous earth (temporary) surrounding seedlings or Large plastic picnic cups (semi-permanent, can be taken up after seedlings grow tall enough and stored for reuse next time) with the bottoms cut out and placed around seedlings (partially buried under the ground and partially sticking out of the ground).
I am really adventurous - Eat them (See Edible Pillbugs)
Or combination/s of the above.