Biological Control of Paterson's Curse with the Flower Feeding Beetle (DSE

February, 1998 Biological control of Paterson's curse LC0165 with the flower feeding beetle ISSN 1329-833X Keith Turnbull Research Institute, Frankston

Common and scientific names developing seed. Larvae complete development in 14 to 20 days, then drop from the flowers to pupate in the leaf litter Paterson’s curse flower feeding beetle or soil. Adults emerge in around 10 days and return to their Meligethes planiusculus (Heer) host to feed on pollen, developing ovules and maturing seed in open flowers. Adults that emerge before the longest Background day of the year may oviposit, leading to a partial second Paterson’s curse (salvation Jane), Echium plantagineum, is generation. At the end of the flowering period adults pass a noxious weed of European origin found through much of the remainder of the summer and the following winter in an Victoria. A national program led by CSIRO Division of inactive state away from their host in the leaf litter or soil. Entomology and in collaboration with the Department of Natural Resources and Environment Victoria (NRE), NSW Agriculture, Agriculture Western Australia and the South Australian Research and Development Institute involves the establishment of populations of the weed’s natural enemies in suitable infestations and redistribution to other sites as populations increase. One of these natural enemies is the Paterson’s curse flower feeding beetle. Keith Turnbull Research Institute has developed a mass rearing program to rear and release the flower feeding beetle onto Paterson’s curse infestations throughout Victoria. Description Figure 1: Adult flower feeding beetle, Meligethes planiusculus Adult: 2 mm long, broad and flattened, with shortened wing covers, exposing the tip of the abdomen, shiny black, Impact active flyers at temperatures around 25 oC and above (figure 1). Adults are generally smaller than the Paterson’s Feeding damage to the flowers and developing seed by curse flea beetles and do not jump like the flea beetles. adults and larvae results in reduced seed production. Egg: 0.6 mm long and 0.25 mm wide, white to opaque in Releases color. Laid in the terminal buds of the flowering cymes. The Paterson’s curse flower feeding beetle has been Larva: Elongate, subcylindrical, white to light gray in released at sites in New South Wales and releases in color, with a small light brown head (figure 2). Victoria will begin in spring 1998. Nursery sites are selected by researchers and local NRE area staff in Life cycle consultation with land owners and Landcare groups. The flower feeding beetles have 1 to 2 generations per A release site should have a dense and persistent year. Adult beetles are dormant over winter and become Paterson’s curse infestation and be connected to active in spring on the developing flower stalks. Here they neighbouring infestations so that the beetle can disperse feed, mate and lay eggs. On average a female beetle lays more readily. The site should have a low priority for around 90 eggs over a period of 31 days. Eggs take around control by other techniques. 4 to 6 days to hatch. The larvae then bore through the calyx and petal to feed on anthers, pollen and ovules within the unopened flower bud. Final instar larvae are mobile and move between flowers on a cyme, feeding on the

For further information on the biological control of Paterson’s curse please contact your local Catchment Management Officer of the Department of Natural Resources and Environment (NRE) or: Keith Turnbull Research Institute, PO Box 48, Frankston, Victoria, 3199. Tel (03) 9785 0111 Fax (03) 9785 2007 email [email protected]

CSIRO Division of Entomology GPO Box 1700, Canberra, ACT, 2601 Tel (06) 246 4406 Fax (06) 246 4177 Figure 2: Beetle larvae feeding in a Paterson’s curse flower email [email protected] Acknowledgments Feeding damage by adults and larvae to the flowers Biological control of Paterson's curse is partly funded by and developing seed results in reduced seed the International Wool Secretariat and the Meat Research production. Corporation and is a project of the Cooperative Research Centre for Weed Management Systems. Prepared by Kerry Roberts & Tom Morley. Integrated control This publication may be of assistance to you but the State of Victoria Four species of insect which attack Paterson’s curse have and its officers do not guarantee that the publication is without flaw already been released in Victoria. The leaf mining moth, of any kind or is wholly appropriate for your particular purposes Dialectica scalariella, was first released in Victoria in and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information 1988 and was well established by 1992. The crown boring in this publication. weevil Mogulones larvatus has been widely released since 1994 and redistributed from 1996 onwards. The root boring weevil Mogulones geographicus was first released in early 1996 and the taproot flea beetle Longitarsus echii was released in late 1996. The complementary effects of these agents are expected to make the weed less competitive. Biological control cannot totally eradicate a weed but can reduce the spread and density of infestations. In some cases control is achieved to the level where the weed is no longer of concern and no other control is necessary. More commonly, other methods are still required to achieve the desired level of control. Biological control should not be considered the complete answer to a Paterson’s curse problem. It is a technique that should be used in conjunction with other control measures in an integrated management plan. Further information Biological Control Notes No. 2. Biological Control of Paterson’s Curse Using the Leaf Mining Moth, Dialectica scalariella. Biological Control of Paterson’s Curse with Crown and Root Boring Weevils. Landcare Note (LC0173): Paterson’s Curse. Landcare Note (LC0159): Biological control of Paterson’s curse with the stem boring beetle. Landcare Note (LC0155) Biological control of Paterson’s curse with the taproot flea beetle.