In this section:
Monterey Pine Aphid
Biological control of Monterey Pine Aphid, Essigella californica
Principal investigator: Dr Richard Glatz
Scientific Officer: Bill Kimber Technical Officers: Gabriella Caon, Nathan Luke
Potential Monterey pine aphid control agent the wasp parasite Diaeretus essigellae
The Monterey pine aphid problem
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Monterey pine aphid was first recorded in Australia in March 1998 on Pinus radiata in Canberra It has now spread through New South Wales and Victoria and into South Australia and Queensland and is now distributed throughout the pine growing areas across Australia. E.californica has also recently been introduced into Europe, found in France (Turpeau &Remaudiere 1990) and Spain (Seco Fernandaz & Mier Durante 1992); it has also been identified from southern Brazil and New Zealand. Monterey pine aphid is a native of western North America, its distribution ranging from southern British Columbia to southern Mexico and east to Nebraska with an additional record in from Miami, Florida. This aphid is not usually a pest in its native locality but has been reported as a minor pest of Christmas tree plantations in central California, mainly causing aesthetic problems. | |
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In Australia E californica is often associated with the defoliation and loss of wood production in radiata pine plantations. A study in 2004 by the Forest and Wood Products Research and Development Corporation found that if defoliation of radiata pine stand continues at the current levels then the potential NPV of losses from 2004-2033 is estimated to be $107 million across NSW, Victoria and the green Triangle. More severe defoliation occurring in drier years with losses up to $40 million per year.
The total reduction in the amount of wood produced across these areas however was estimated to be worth an average of $21 million per year, (May,B 2004). |
Fig 1. Monterey Pine Aphid Adult on Pine Needle. |
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Potential biological control agent: Diaeretus essigellae D. essigella was originally collected and described from California. It is proposed to arrange the collection of the wasps in California were "mummy" cases would then be sent to the quarantine insectary at the Waite Precinct in Urrbrae SA. Emerging adults would be collected and used to establish cultures. These cultures will be used to test the wasp parasite for specificity. If there is no parasitism with "test " aphids which currently occur in Australia permission will be sort to release the agent. | |
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Mode of Action The adult wasp search for aphid nymphs on pine needles and lays their eggs into live nymph stages (one egg per aphid). The eggs then hatch into larval grubs and start feeding on the internal membranes of the aphid. As the grub matures within the aphid body the aphid dies. The outer skin of the dead aphid hardens and forms a cocoon known as a "mummy " which attaches itself to the pine needle. The adult wasp emerges from this mummy case to continue to the next generation. |
Fig 2. Diaeretus essigella, female wasp |
