Diversity and Seasonal Occurrence of Native and Nonnative Ants (Hymenoptera: Formicidae) in Long-Term Experimental Chinese Privet (Lamiales: Oleaceae) Plots in Georgia, USA

Abstract

Chinese privet (Ligustrum sinense Loureiro) (Oleaceae) is a shade-tolerant invasive shrub first introduced from China into the US in the mid-19th Century as an ornamental (Wyman 1973, Shrubs and Vines for American Gardens, Macmillan, NY). Chinese privet is an aggressive invader across the southeastern United States and is now found in 27 U.S. states, including Hawaii (EDDMapS, http://www. eddmaps.org/; 20 May 2021), resulting in loss of native species richness across much of its invaded range (Hanula et al. 2009, Invas. Plant Sci. Manag. 2: 292–300; Hudson et al. 2014, Forest Ecol. Manag. 324: 101–108; Merriam and Feil 2003, Biol. Invasions 4: 369–373; Wilcox and Beck 2007, Southeast. Nat. 6: 535–550). Ward (2002, Southeast Geogr. 1: 29–48) documented an 8% increase in Chinese privet cover in the Upper Oconee River floodplain in northern Georgia between 1951 and 1999. Where Chinese privet establishes, it can dominate as an understory monoculture (e.g., Wilcox and Beck 2007), reducing flowering plant richness needed to support pollinators and, over the long term, likely reducing woody debris diversity necessary as harborage and food for a number of arthropods. Several studies have investigated these impacts of Chinese privet infestation on various taxa, including arthropod communities, with most reporting similarly negative results. A more abundant and diverse bee fauna was found on Chinese privet removal plots compared to control (infested) plots 1 and 2 yr after treatment, and again 5 yr after treatment (Hanula and Horn 2011a, Insect. Conserv. Divers. 4: 275–283; Hudson et al. 2013, Biol. Conserv. 167: 355–362). In a later study on bees at the same study