The brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is an invasive pest causing significant agricultural losses in the USA, particularly among USDAcertified organic agricultural operations that are prohibited from using synthetic pesticides. Recent research indicates that for optimal development, nymphs of H. halys require gut microbial symbionts that are acquired from the egg mass. This research investigated the impact of ‘compost teas,’ biologically-active organic matter emulsions that are commonly applied as foliar sprays for pathogen management in organic agriculture, on H. halys during early stages of development. We compared H. halys development after misting egg masses and neonates with reversed osmosis water (control), or with a 50/50 mixture of compost teas derived from poultry manure and mushroom waste. The compost tea treatment significantly affected hatch (%) for egg masses of H. halys that were treated initially within 24–30 h of deposition, resulting in a 13% reduction in hatch, as compared to the control. Furthermore, significant 2-fold increases in mortality were found for 1st and 2nd instars in the compost tea group, as compared to those in the control group. For egg masses initially treated later (i.e., 2–3 days after deposition), the compost tea treatment resulted in a significant 3-fold increase in mortality (%) for 1st instars, compared to the control. These findings suggest that compost tea holds potential for developing an organic management tactic for H. halys and warrant future investigation of potential underlying mechanisms, including antagonistic interactions with microbial gut symbionts and antibiotic compounds that could penetrate the egg chorion.