Preliminary assessment of potential biocontrol agents of Iris pseudacorus L. in the invaded range

GERVAZONI, PAULA; FUENTES RODRIGUEZ, DANIELA; SOSA, ALEJANDRO; COETZEE, JULIE; BERTUCCI, SABRINA; KRAMARZ, DAHIANA; FRANCESCHINI, CELESTE

Simposio; V Simposio Chileno de Control Biológico; 2022

Iris pseudacorus L. (Iridaceae) (yellow iris) is an invasive alien species (IAS) native from Europe, North Africa, and West Asia. This species not only causes economic impacts by invading rural and urban areas, but also produces a great damage to wetland’s native biodiversity in many countries of the world. Currently, there is an international alliance between Argentina, South Africa, Belgium and New Zealand, aimed at testing the feasibility of applying classical biological control against this weed with the candidate Aphthohanonstriata, native from Europe. However, there are still no assessments of potential biocontrollers already associated with I. pseudacorus in the invaded range. We analyzed the biodiversity of insect assemblages associated with I. pseudacorus in Argentinian wetlands. Systematic and random sampling were carried out in urban, rural, natural and artificial invaded wetlands, in the Pampean, Central and Northwest regions of Argentina, taking into account aerial parts of plants and capsules. As preliminary results, 343 individuals corresponding to 11 orders were obtained, being the most abundant Hemiptera, Diptera and Coleoptera. The most represented species of herbivorous insects belonged to the families Aphididae, Pentatomidae and Curculionidae. Several coleopteran species were recorded feeding on seeds inside the capsules, among which Araecerusfasciculatus was the most represented. These results indicate an absence of species with biocontrol potential for I. pseudacorus in the sampled sites. Although herbivorous insects were recorded on the plant, many of them can be attributed to occasional visits due to their low representation. Regarding the most abundant species, they correspond to polyphagous species, and cannot be considered for weed biocontrol. These results emphasize the need to continue testing the feasibility of applying classical biocontrol with candidates from the native range of the plant that demonstrate specificity for I. pseudacorus.