PestFacts August 2021

Helicoverpa reports and trapping network

Native budworm (Helicoverpa punctigera) has been reported in early peas in the Mitchellville area. They are currently only feeding on the green leaf and not on pods.

The spring trapping network

The SARDI Entomology Helicoverpa moth pheromone trap network is currently being organised to help identify when Helicoverpa flights occur this spring. Understanding the timing of moth flights can provide:

• early warning of potential caterpillar activity in crops
• insight on when to monitor for target size caterpillars.

Flights of native budworm moths are not an indication that control is needed in paddock. Early sprays based on moth flight numbers alone will not be beneficial as target size caterpillars won’t be in the paddock and won’t be controlled. Always monitor actual insect pressure before deciding on management.

At each location, we are separately trapping the two common Helicoverpa species:

• native budworm (H. punctigera)
• corn earworm (H. armigera).

Once the network is finalised and set up, we will provide weekly updates of moth trapping data during spring – watch the PestFacts Twitter for updates.

How you can help

Do you have pulse crops that you regularly monitor? Join our network of volunteer trappers and help strengthen our insights.

If you are happy to set up and monitor moth pheromone traps weekly, get in touch today. We are particularly looking for pulse monitoring from:

• Lower Yorke Peninsula
• Kangaroo Island
• Mallee.

If you would like to be part of the trapping network or would like more information, please contact:

Rebecca Hamdorf
Mobile: 0429 547 413
Email: rebecca.hamdorf@sa.gov.au.

Regional overview of recent pest observations

Over the past few weeks, we have received only isolated reports of pest activity. This is possibly due to the wetter July limiting insect numbers. After checking in with regional agronomists, we can report the following recent observations:

Springtail activity

Lucerne flea

There were higher than normal numbers of lucerne flea (Sminthurus viridis) on wheat and barley around Crystal Brook, which have been sprayed out.

In the South East, below average to average numbers of lucerne flea were reported in pasture.

Only low numbers have been reported on the Yorke Peninsula.

Plants are most susceptible to lucerne flea feeding at emergence, so we would not expect them to be problematic in the coming months.

Purple scum springtails

Purple scum springtails (Hypogastura vernalis) have been reported in paddocks with stubble around Kapunda and Kangaroo Island. They are a beneficial invertebrate that feeds on decaying organic matter and are most often seen in rafts on puddles after rain.

Aphid activity

No aphid activity has been seen by reporters in the Mid North, Yorke Peninsula or the South East.

Russian wheat aphid

Russian wheat aphid (RWA, Diuraphis noxia) has been reported on the Lower Eyre Peninsula. This has mainly been on untreated cereals, however, their presence varies depending on local conditions including nearby volunteer cereals and weeds.

The wet and cold weather seems to have reduced earlier population numbers, possibly through entomopathogenic fungi attacking them. With the good rains increasing growth and tillering, cereal plants will be able to resist RWA quite well.

For more information on when to monitor and if you need to manage RWA, go to the the RWA action threshold calculator.

Cabbage aphid

Cabbage aphid (Brevicoryne brassicae) is starting to be seen in low numbers on canola in the Lower Eyre Peninsula.

Cabbage aphid can be distinguished from other canola aphids by the thick coating of waxy powder – but be aware that newly moulted aphids can look bright green until they develop the coating again! They are typically found on the terminal flowering spikes.

Weekly monitoring from late winter into spring can be beneficial. Aphids tend to move into paddocks from the edges so will be there first and distribution can be patchy so check at least 5 locations.

Caterpillar activity

Armyworms

Armyworms have been reported feeding at Yeelanna but are not expected to be an issue. There are two periods of armyworm feeding:

• late autumn and winter (low to moderate economic risk)
• late spring (when head lopping can occur; high economic risk).

Armyworms feeding now, especially large individuals, will pupate before spring.

Brown pasture looper

Higher than usual numbers of brown pasture looper (Ciampa arietaria) feeding on pasture have been reported in the South East. A few brown pasture loopers were also reported in a wheat crop at Brinkley, likely feeding on broadleaf weeds in the paddock.

Brown pasture loopers are often prevalent around patches of capeweed and at the edge of crops.

Native budworm

Native budworm (Helicoverpa punctigera) has been reported in early peas in the Mitchellville area. They are currently only feeding on the green leaf and not any pods.

The PestFacts Helicoverpa spring trapping network will begin soon.

Source of reports: Iain Tod (Kerin Agencies Crystal Brook), Steve Richmond (Nutrien Jamestown), Nigel Myers (Nutrien Cummins), Adam Hancock (Elders Naracoorte), Jarrad Schiller (Cleve Rural Traders), Maree Gifford (Elders Kingscote), James Chard (Growers Suppliers), Chris Davey (YP Ag), David Millan (Nutrien), Giles Kearsey (Nutrien).

How to report

PestFacts SA always wants to know what invertebrates you are finding in your crops and pastures, whether it is the ‘usual’ pests, beneficial or unknown. Reports of not seeing anything are valuable too! Please send your reports or identification requests via the PestFacts Map online report form.

Alternatively, please contact:

Rebecca Hamdorf
Phone: 0429 547 413
Email: rebecca.hamdorf@sa.gov.au

Maarten van Helden
Phone: 0481 544 429
Email: maarten.vanhelden@sa.gov.au