may overcome by individual crazy ants that have a restricted sugar intake, which may
occur when crazy ants are excluded from resources by fire ants.
Introduction
Biotic interactions between introduced species and native or pre-established
exotic species are important influences on the success and spread of invasive species
(Mack et al. 2000, Mitchell and Power 2003, Ness and Bronstein 2004, Torchin and
Mitchell 2004). Competition from established species in the introduced range, like
between ant species for food or territory, can sometimes serve as biotic resistance to
invasive species (Walters and Mackay 2005, Menke et al. 2007). Competitive
interactions can be exploitative, where individuals compete indirectly via their effects on
shared resources, or interference, where individuals directly clash through antagonistic
behaviors (Ricklefs 2001). In ants, interference competition is common and can cause
death or injury of workers and loss of access to food or territory (Savolainen and
Vepsalainen 1988, Holldobler and Wilson 1990, Andersen and Patel 1994). Therefore,
interference competition can be an important factor in the spread and success of an exotic
ant pest, such as the recently introduced Rasberry crazy ant, Paratrechina sp. nr. pubens.
In this paper, I examine direct intraspecific competitive interactions between crazy ant
nests and direct interspecific competitive interactions between crazy ants and an
extremely common invasive ant in its introduced range, Solenopsis invicta, the red
imported fire ant. Intraspecific and interspecific interactions OfRasberry crazy ants have
never been examined, yet the ant is a pest species that is increasing its introduced range
southeast of Houston, TX. To my knowledge, no studies have examined competition