Biological control of lippia (Phyla canescens): surveys for the plant and its natural enemies in Argentina

SOSA AJ; TRAVERSA MG; DEHLEY R; KIEHR M; CARDO MV; JULIEN M

La Grande Motte

Simposio; XII International Symposium on Biological Control of Weeds; 2007

Lippia, Phyla canescens (Kunth) Greene (Verbenaceae) is a fast-growing, mat-forming plant native to South America. It is considered a weed in Australia, where it was introduced as ornamental during the nineteenth century. The knowledge about the biology of lippia is currently limited to unconcluded taxonomical studies; there is scarce information about the ecology and natural enemies in the native range. Surveys for the plant and its natural enemies were initiated in Argentina in December 2005 in order to determine the centre of origin and native range of the weed and to search for possible biological control agents, both insects and phytopathogens. So far, the weed was recorded in 38 out of 85 sites sampled, mostly east of 65º W, circumscribing the weed to the Chaco domain. In such places, at least 14 insects and 12 fungi were found. Among insects, the most promising candidates are three flea beetles (Chrysomelidae). Pathogens include the rust Puccinia cf. lantanae, Cercospora cf. lippiae and three Colletotrichum spp., associated with leaf spots and stem cankers. Additional information on their biology and host specificity is required in order to propose any of these as biocontrol candidates.