Author
Andrew J McConnachie
andrew.mcconnachie@dpird.nsw.gov.au
NSW Department of Primary Industries and Regional Development
Orange
Coauthors
Asad Shabbir, asad.shabbir@dpird.nsw.gov.au, NSW Department of Primary Industries and Regional Development, Orange
Eduardo A Filho, University of Blumenau (FURB), Brazil
Marcelo D Vitorino, University of Blumenau (FURB), Brazil
Abstract
Harrisia martinii (Cactaceae, Harrisia cactus) is a weed in Australia, causing ecological and economic impacts in rangelands and natural areas. A biocontrol program was undertaken in the 1970s culminating in the release of three agents. One of these, Eriocereophaga humeridens (Coleoptera: Curculionidae) failed to persist in the field due to the success of one of the other two agents. This project sought to reassess its risk for introduction based on contemporary host-range testing. The weevil was field collected in Brazil and tested there and in Australian quarantine. The results demonstrated that while H. martinii and Harrisia adscendens remained the most suitable hosts, feeding and development also occurred on species of Hylocereus and Selenicereus. In no-choice tests, these genera consistently received feeding scars and varying levels of oviposition, with some species supporting development to adulthood. Although performance was generally lower than on Harrisia spp., the ability of the weevil to feed, oviposit, and in some cases complete development on dragon fruit and related taxa, highlights a potential non-target risk. Overall, the results indicate that while E. humeridens is strongly associated with Harrisia spp., the potential risk to commercially important Hylocereus and Selenicereus species cannot be excluded. These findings recommend caution in considering this insect for biocontrol in regions where dragon fruit cultivation is economically important.
keywords
Eriocereophaga humeridens
Harrisia
host-range
Highlights
E. humeridens attacks Harrisia spp. but also feeds and develops on dragon fruit cacti
Most Opuntia and allied species supported limited or inconsistent development of E. humeridens
There is AUD 3.2 million dragon fruit industry in Australia, so caution is required