Asparagus weeds - Weeds Australia

Control methodsSince they were introduced,the leafhopper and rustfungus have been widelyreleased across southernAustralia. They havemost likely colonised allareas suitable for theirdevelopment. Redistributionof these agents is mainlydone to acceleratedevelopment at specificsites in some years byincreasing their populationat the beginning of thegrowing season.The leaf beetle hasestablished poorly, so thereis currently no scope toredistribute it.Note: The Western Cape form of bridal creeper, which isfound in limited areas of South Australia and south-westVictoria, is not impacted by the bridal creeper rust fungus.Western Cape bridal creeper (left) stands outamong rust infected common bridal creeper (right)Shauna Potter, Biosecurity SABridal creeper biocontrol agentsAgent Appearance Damage Life cycle StatusLeafhopperWhite, 2–3 mmlong, living onunderside ofbridal creeperleaves.Sap-sucking insect that feeds on thephotosynthetic leaf cells (visible assilver patterning on the leaves). Adultsand juvenile stages feed on the leaves,causing them to turn white and, insevere cases, fall off. Continued damageover several years reduces new tuberproduction, making bridal creeper lesscompetitive.Lays about 200 eggs over 6 weeks, andhas multiple generations each year.Widely established acrossAustralia. By 2008, releasedat close to 900 sites. Used inWeed Warriors program aseducational tool (see page 67).Rust fungusYellow pustulessurroundedby yellowingtissue on theunderside ofleaves.Attacks leaves and stems, divertingnutrients away from healthy plant tissue.Can have a major impact on the levelof reserves normally stored in tuber. Insevere cases, leaves die off.Complicated, with 5 spore stagesincluding one that survives oversummer when bridal creeper hassenesced. Many generations per year,and produces large amounts of winddispersedspores.Widely established acrossAustralia. By 2008, released atmore than 2100 sites. Spreadswithin and between bridalcreeper infestations efficiently.Leaf beetleAdults and larvae feed exclusively onbridal creeper’s young, expandingtissues. Larvae strip shoots and leavesand prevent plants from climbing,thereby reducing fruit production.Active in autumn and early winter(February to July) and does notcompete directly with above agentsfor resources. From early winter, adultfemales lay eggs on expanding shootsand leaves, either singly or in groupsof up to 10.Poorly established. By 2008,released at 82 sites acrosssouthern Australia (except TAS)but confirmed established atonly three sites, possibly due topredation or parasitism.66