Although A. diaperinus is not considered of major economic importance to whole grains, it does occur commonly on products already damaged by other biological agents, especially molds. However, it is of considerable importance in the poultry business as an avian disease vector, and there are human health risks associated with exposure to A. diaperinus. Poor community relations can also develop with, costly litigation when adults fly en masse to the artificial lights at private residences from beetle-infested manure (Hinchey 1997).
Lesser mealworms can also cause poultry house structural damage. When searching for suitable pupation sites, larvae will chew holes in styrofoam, fiberglass, and polystyrene insulation panels in the walls of poultry houses. The resulting damage can cause increased heating bills and additional building repair costs when the infested area is replaced. Energy costs in beetle-damaged broiler houses are reported to be 67% higher than in houses without beetle damage (Geden and Hogsette 1994).
I think you may also be forgetting that chickens are a natural benefit to your garden anyway as they work as a natural pesticide themselves. Let them graze your garden and feed on the pests that are already bothering you.