Anisops sp. is capable of rapidly and abundantly colonising wetlands after inundation, which can influence the ecological structure of planktonic communities through top-down predatory effects1. The diet and predatory behaviour of Anisops sp. has been explored in laboratory-based experiments, however, few studies have considered the effects of predation by Anisops sp. in natural populations3. This study examined the effects of Anisops sp. predation upon natural zooplankton communities. We established the following treatments in four replicated 90L open mesocosms: (1) Control without Anisops; (2) Low predator density (10 individuals added); (3) High predator density (40 individuals added). Each mesocosm was seeded with a natural population of zooplankton (Cladocera, Copepoda, Ostractoda) 15 days prior to the experimental period2. 1L was collected from each mesocosm 7 days before the addition of Anisops sp., then every 7 days after for 35 days, for the purpose of zooplankton identification and enumeration. Differences in species abundances between treatments were tested using multiple one-way ANOVAs; changes in species abundances over time were tested using repeated measures ANOVAs. We found that the abundance of Ceriodaphnia sp. was significantly lower in mesocosms with Anisops sp. present. Other classes of zooplankton fluctuated in relative abundance through time but did not appear to be affected by the presence or density of Anisops sp. This is supported by previous ex-situ research that suggested predatory hemipterans may drive top-down effects on planktonic community structure2,3, indicating the predatory behaviour of Anisops sp. is an ecologically relevant mechanism in wetland ecosystems.