Monitoring the invasion of the aquatic bug Trichocorixa verticalis verticalis (Hemiptera: Corixidae) in the wetlands of Doana National Park (SW Spain)

We have detected the presence of the North American native corixid Trichocorixa verticalis verticalis (Fieber, 1851) in Doana wetlands (SW Spain). We have collected data from different research projects done in the area during the period of 2001-2007. We have sampled 134 different sites in Doana and we found the exotic corixid in 66 occasions. We have found two reproductive populations that might act as sources for the colonization of other waterbodies in the area. When reproduction occurred T. v. verticalis outcompeted native corixids. Its presence out of the waterbodies where we detected reproduction was in small numbers and probably due to vagrant individuals.