Mealy bugs
- Kondinin
Ben Whisson (ConsultAg) recently found mealy bugs on a tillering barley crop near Kondinin.
Mealy bugs are tiny sap-sucking pests that generally have a broad host range. When viewed under magnification they have a soft, oval, convex and segmented body with no distinction between head, thorax or abdomen. They are covered in white wax and have a fringe of marginal filaments which can look like extra legs. They are generally suited to warm and humid conditions and do best in glasshouses and on indoor plants where they are more commonly known.
Mealy bugs are generally uncommon in broadacre farming although they have been found on cereals in previous seasons. They have been known to generate into moderate numbers on volunteer plants prior to crops being sown in early autumn and then transfer across onto newly established crops. They are not considered a serious problem to crops but have been recorded as doing some damage in the heads of barley.
For more information refer to DPIRD’s Aphids, mealy bugs and scales page.
For more information contact Research scientist Svetlana Micic, Albany on +61 (0)8 9892 8591.
Article author: Cindy Webster (DPIRD Narrogin).
Green peach aphid and turnip yellow virus update
- Northam
- Toodyay
- Gibson
- Kendenup
- Woogenellup
- Takalarup
The Department of Primary Industries and Regional Development’s (DPIRD) monitoring of green peach aphid (GPA) activity at sites in the Kwinana West, Albany and Esperance region continues. Yellow sticky traps have been put on fencelines to catch migrating aphids, and DPIRD staff are also conducting crop inspections and virus testing of captured aphids and inspected crops.
Winged GPA have recently been caught on traps set up at Northam and Toodyay. They have also been found infesting some crops in this area. These crops are being testing for presence of turnip yellows virus (TuYV) which is transmitted by GPA, and can cause up to 50% yield losses when the crop becomes infected during the vegetative growth stage.
GPA have also been found infesting crops at various sites in the Albany port zone. TuYV has been detected in flying aphids caught on sticky traps in Gibson, but the presence of GPA has not been confirmed.
Therefore, growers/advisors in the Kwinana West, Esperance and Albany port zones should be monitoring young crops over the next couple of weeks.
DPIRD is not monitoring crops in the Geraldton or Kwinana East port zones. Therefore, if growers or agronomists operating in these regions observe aphid infestation or virus-like symptoms in crops, please contact DPIRD Research Scientist Benjamin Congdon on +61 (0)8 9368 3499. Canola plants can also be tested for the presence of virus through the Department’s Diagnostic Laboratory Services – Pathology Services.
The aphid population growth rate is likely to have been reduced due to the recent cold conditions. Additionally, when temperatures drop below 16°C, aphids are unlikely to fly, which decreases the probability of widespread virus infection caused by them. Furthermore, heavy rain can cause aphid mortality as it dislodges aphids from plants. However, if daytime temperatures exceed 16°C in the coming weeks, aphid populations in certain areas where they are already present will continue to grow and disperse. This may pose a risk to crops that are still in their vulnerable growth phase (pre-flowering). Crops that have begun stem elongation and are aphid and virus free are now in the safe zone. The use of insecticides to control certain aphid/virus combinations (such as cereal aphids/yellow dwarf viruses and GPA/TuYV) in these more mature crops is unlikely to provide any economic benefits.
For insecticide recommendations refer to DPIRD’s 2023 winter spring insecticide guide.
To read about earlier aphid and TuYV activity this season refer to the 2023 PestFacts WA Issue 6 article Green peach aphid alert and Issue 5 article Early season aphid and virus risk in cereals and canola.
For more information refer to DPIRD’s Turnip yellows virus early warning system page and Turnip yellows virus in canola: diagnosis and management page.
For further information contact Research scientist Benjamin Congdon, South Perth on +61 (0)8 9368 3499.
Article author: Benjamin Congdon (DPIRD South Perth).
Slaters
- Ongerup
- Borden
- Wellstead
- Gairdner
Slaters are causing damage to canola crops near Ongerup, Borden, Wellstead and Gairdner. They are noticeably present in later sown crops that have experienced moisture stress and in paddocks with heavier loams and clays.
Slaters have a hard skeleton on the outside of their bodies, seven pairs of jointed legs, and two pairs of antennae.
Slaters survive on organic matter on the soil surface. If the organic matter dries out the slaters cannot survive. The heavy stubble load on the reported paddock aided their survival over summer.
Entomologist Svetlana Micic (DPIRD) says that in some years, slaters can be difficult to control.
At crop germination the only option is to bait or to spray. Baits registered for slater control have better efficacy than baits registered only for mollusc control. The application of residual insecticide sprays have had some efficacy in protecting a germinating canola crop from slater damage. However, as slaters are nocturnal and shelter under stubble it can be difficult to get good spray coverage for their control.
For more information refer to DPIRD’s Diagnosing slaters in crops and GRDC’s Mitigating snails, slugs and slaters in Southern Western Australia.
For more information contact Research Scientist Svetlana Micic, Albany on +61 (0)8 9892 8591.
Article author: Svetlana Micic (DPIRD Albany).