EFFECTS OF IRIS PSEUDACORUS ON INVERTEBRATE COMMUNITIES IN A SOUTHERN CALIFORNIA ESTUARY

Anita Arenas; California State University of Long Beach; arenas2085@gmail.com;

About 90% of wetlands have been lost in California. Of those that remain, many are degraded by invasive species, such as Iris pseudacorus (IRPS). IRPS has invaded freshwater (FW), brackish (BW), and marine (MW) wetlands in southern California estuaries. Using various sampling methods, our objective was to determine if IRPS impacts the invertebrate community relative to uninvaded areas in Los Peñasquitos Lagoon in North County San Diego. Preliminary data collected using sticky traps showed no difference in abundance of aerial insect communities between IRPS and non-IRPS canopies in FW and BW, but there was higher abundance in IRPS relative to non-IRPS at MW. The aerial insect community composition differed among sites with more Culicidae and Muscidae in FW, higher Agromyzidae in BW, and higher Thysanoptera in MW. Pitfall traps showed differences among sites and plot types where FW sites had higher abundance compared to BW sites, and abundance was higher in non-IRPS compared to IRPS. Community composition showed more Linepithema humile and Transorchestia enigmatica in the FW compared to BW. Exploring the impacts of IRPS on insect communities can inform and prioritize management strategies by determining the extent of impacts and most impacted locations.

Invertebrate Conservation   Student Paper InPerson Presentation