Natural enemies of the invasive plant Harrisia martini (Caryophyllales: Cactaceae): Perspectives for biological control from native and introduced areas

FRANCESCHINI M. CELESTE; DUFEK, M.; KELK, L. ; MEDINA, W.; CABAÑA FADER, A.; DEL VALLE, G.; DAMBORSKY, M.; TAYLOR, TAMARA

Puerto Iguazú

Simposio; XVI International Symposium on biological control of weeds. Session Target and agent selection.; 2023

FuEDEI y CERZOS (CONICET), International Organisation for Biological Control (IOBC)

Harrisia martinii is a much branched, erect to climbing cactus with a native range fromeastern Paraguay to northeast of Argentina. In Australia this species is invasive and canform dense infestations, choking out other pasture species and causing injuries to livestock.Harrisia cactus was introduced to Australia in the 1890’s. Since then, it has been steadilyincreasing in density and distribution in Queensland and New South Wales. In Australia,integrated management strategies for this cactus include chemical and mechanical control,as well as biological control with agents that were imported from Argentina in the 1970sand 1990s. However, an adequate level of control has not been achieved. The aim of thisresearch project is to further the knowledge of the interactions between Harrisia martiniiand its natural enemies in the native range of Argentina, with a view to utilizing insectsfrom Argentina as biological control agents in Australia. The research focuses on twobiocontrol agent candidates: the fly Dasiops bourquini (Diptera: Loncheidae) and the beetleNealcidion cereicola (Coleoptera: Cerambycidae). After localization and collection of theinsects from the north of Argentina, laboratory cultures will be established for furtherobservation. Field observations will also be carried out to understand the environmentalrequirements and mating habits to rear these species. Once the methodology has beenestablished, a small collection from the laboratory cultures in Argentina will be exportedto Australia. Methods and environmental conditions used in Argentina will be replicated atthe Queensland Department of Agriculture and Fisheries (QDAF) quarantine laboratoryfacility in Brisbane to produce new cultures that will be used for host-specificity testing onsignificant and economically important species. This project is relevant because very littleis known about the biology and ecology of D. bourquini and N. cereicola. This researchwill further the knowledge of these two native insect species in Argentina and establish acollaborative relationship with biological control researchers in Australia. If the insects areproven to be safe and are approved for field release in Australia, this work will beinstrumental in helping to control one of Australia’s worst invasive species.