Opiine parasitoids (Hymenoptera: Braconidae) and biological control of fruit flies (Diptera: Tephritidae) in Australia: Past, present and future

Abstract

AbstractOpiine braconids are parasitoids of the immature stages of frugivorous tephritids. The female wasp lays her eggs into the eggs or larvae of the fruit fly host, where the immature wasp develops before emerging as a next‐generation adult from the now dead host pupal case. In support of a new generation of Australian fruit fly parasitoid research, this paper comprehensively reviews what is known about the Australian fruit fly infesting opiines. Based on the most recent taxonomic revision 11 fruit fly infesting opiine species are documented to occur in Australia, but we consider as doubtful the record forDiachasmimorpha longicaudataand consider the record forFopius illusoriusto be tentative without further collections. We identify that the systematics and taxonomy of the Australian native fruit fly infesting opiines are in urgent need of further work. The history of fruit fly biological control in Australia is comprehensively reviewed, including the export of native Australian opiines for fruit fly control elsewhere in the world. Australia was actively involved in three major classical biological control programmes against fruit flies from the turn of the 1900s until the mid‐1960s. Despite the introduction of 11 opiine species, plus numerous other natural enemies, onlyFopius arisanusestablished in eastern Australia, where in South‐east Queensland it can now cause between 30 and 40% mean parasitism. In addition to the exoticF. arisanus, the native speciesDiachasmimorpha kraussiiandDiachasmimorpha tryonialso cause fruit fly parasitism in agriculturally important crops: both species have also been liberated widely outside of Australia for fruit fly control. Other Australian opiines have not been reared from flies infesting commercial crops and appear biologically restricted to the fruits and environs of Australian east‐coast rainforests. The biology literature forD. tryoniandD. kraussiiis comprehensively reviewed, while forF. arisanus, already reviewed elsewhere, key literature only is covered. Forward looking, we consider the potential for inoculative or inundative releases of opiines in areas where they do not currently occur to be good, while conservation biological control may help to increase the impacts of parasitoids in areas where they are already established.