Aphids (Green peach, Turnip, and Cabbage species)

Constraint - Aphids

Description

• Small insect pests with oval green brown or black bodies

• Occur in large colonies

• Can be winged or wingless

• The agricultural significance of aphids lies primarily in thier ability to trasnmit viruses through feeding

Symptoms

• Aphids feed on sap and may cause wilting, yellowing, stunting or distortion of plant parts

• Sooty mould can sometimes develop on leaves

• Infestation can also reduce flowering and pod set, and seed quality

Damage

• Direct feeding rarely causes damage unless infestation is severe or crop is stressed 

• However, aphids can also transmit the three viruses that affect Australian canola, Beet western yellows virus, Cauliflower mosaic virus, and Turnip mosaic virus

• As with most viruses, yield loss is very hard to measure

Control

Controlling broadleaf weeds, particularly over summer, as well as sowing at recommended times, promoting population of beneficial predators by using selective insecticides if possible, and using chemical control methods are all management strategies to decrease the risk of damage by aphids. Beneficials may not arrive in crop early enough to prevent the build up of aphid numbers to above threshold levels, but  can be important in suppressing population build-up following control, and are effective against low to moderate infestations. 

 

 

Links and Resources

AOF - Insect pests of Canola. Aphids Page 4 of 6. Whole section on aphids, including introduction, habitat, risk factors, predation and yield impact, and management.

CSIRO - Taking the fight to aphids 3 page PDF. Introduction, feeding habits and reproduction, canola damage, biological control, predictive modelling, insecticide resistance, and future management practices. Published 2009. File size: 458kb

DAFWA - Pests of Canola Page 20. Information on description, lifecycle, damage, and control. Published 2005. File size: 458kb

DEPI VIC - Canola diseases. Aphids Information on the three viruses, including symptoms, disease cycle, and management. Published 2008, updated 2009, reviewed 2010. File size: 458kb

DPI NSW - Virus diseases in Canola and Mustard. Aphids 6 page PDF. Introduction, distribution, virus species and their transmission, symptoms, incidence, spread, aphid identification, control measures, and current research. Published 2004. File size: 458kb

GRDC - Best Practice Management Guide. Aphids Page 51. Introduction, verification of aphids as minor pests except when very early in the life of the crop. Published 2009. File size: 458kb

NIPI - Aphids in Canola Information on diagnosis, monitoring and recording, beneficial insects, cultural control, thresholds, chemical control, multi pest considerations, and discussion. Published 2014. File size: 458kb

PIRSA DAFWA & CESAR - I Spy Manual. Aphids Section 4, pages 41-42.  Description/distinguishing characteristics, confused with/similar to, distribution, pest status and risk period, host range, damage symptoms, monitoring and sampling, and management options. Published 2012. File size: 458kb