Lettuce Aphid (Nasonovia ribis-nigri)

Lettuce Aphid can have devastating effects on lettuce crops, to the point of total wipeout of complete patches. Lettuce Aphid like to feed on the inner leaves of the lettuce making it hard for chemical sprays to penetrate and kill them.

Lettuce aphid coloinizing in centre of head
Lettuce Aphid Coloinizing in Centre of Head

Apterous (wingless) lettuce aphid
Apterous (wingless) Lettuce Aphid 		Winged lettuce aphid
Winged Lettuce Aphid


There are currently 3 methods available to combat the pest:
  1. Chemical drenching.
  2. Nasanovia resistant varieties.
  3. IPM.

1. Chemical Drenching of Seedlings in Nursery

Using CONFIDOR® as a drench treatment in the Nursery gives the best results. Rates recommended vary between 35ml through to 50ml per 1000 plants in 2 to 3 litres of water. Using the higher rate in peak season. Talking with leading lettuce growers overseas, they found that applying CONFIDOR® through their travelling booms gave them good and even coverage. It is most important that all trays are treated evenly. It was experienced that if you did not get proper coverage that aphid damage was still evident. CONFIDOR® must be used as a drench to achieve systemic action, uptake in the plants. This is giving the plant protection right through its growing in the field.

Last season we treated many of iceburg and cos growers' lettuce without too many problems and it worked very well on the aphids present at the time with no reports of uncontrolled outbreaks of the aphids that existed last season (not the Nasonovia lettuce aphid).

We are accredited to apply the product, and in fact the SA dept of Ag adopted our protocols as the industry standard in applying the drench to seedlings.

For further info visit - www.bayercropscience.com.au

Spray unit
Spray Unit 		Close-up of spray unit
Close-up of Spray Unit

2. Nasonovia Resistant Varieties

These varieties play an important role in the control of Lettuce Aphid. As we all know the continuous use of CONFIDOR® will result in a resistance issue. Boomaroo Nurseries in conjunction with all seed companies embarked on Nasonovia resistant variety assessment program. We found some promising results such as:

    ICEBURG
      CARTAGENES from RZ is a good even summer lettuce with a short core.
      DELINAS and ARDINAS have shown potential as early and late vars.
      BARCELONA from HENDERSONS has also shown promise as a shoulder variety early and late.

    COS
      SHREK from SPS has shown the most promise of the cos types as an excellent processing cos, whilst still being good enough for the fresh market. SPS say it can be grown year round. It should be evaluated in all programs.

    COLOURS
      A range of butters, corals, oaks and multileaf varities are on the market to be evaluated. Contacting RZ, SPS and Hendersons will give you a list of the range of varieties they have available at the moment.

You find Nasonovia resistant varieties in our Varieties pages or Contact your area representative for more detailed info.

3. IPM

We do not know the effectiveness of this system, but it does rely on the fact that some aphids must be present in the lettuce for the beneficial insects to feed on. Monitoring of crops is needed. Reports have shown that good numbers of predator bugs, eg. Brown Lace Wing and Hover Flies, have assisted in keeping Lettuce Aphid numbers under control in the early stages. Unfortunately it has been noted at time of harvest that predators have been found inside the lettuce as well as aphid culminating in non-sales of lettuce.

With CONFIDOR® being used as a drench, it has been noted that unfortunately these predators are not active on the plants, they have been wiped out as well as the aphid.


Other Practices to Assist Control

Crop Monitoring

Inspection of the crops closely will be a must. For accurate monitoring in the field this will involve total destruction of headed lettuce so as to know what numbers of aphid are present. This should be done on a weekly basis. In peak pressure times monitoring up to twice a week may be required.

Inspecting Trays
Inpsecting Trays


Training of Staff

Having the staff well trained in what to look out for is important, as they will usually be the first to detect any aphid activity.

Hygiene and Cleanliness

Having a clean growing area will assist in keeping aphid pressure to a minimum, not only on the farm but also in the nursery. Certain weeds can be hosts to Lettuce Aphid, eg. Hawksbeard and Sow thistle. Removal of old crops quickly will also help minimise pressure.

Handling of Plants

Once the grower has received delivery of his plants it will be Important that no over watering before planting is done. It is important that no washout of CONFIDOR® occurs as this could compromise the effectiveness of CONFIDOR®. So the practise at the moment where plants are given a big hand water by the grower just before planting will have to be reviewed.

For more detailed information it is recommended you contact your local D.P.I. who can give you up to date information on how best to protect your crops.

You can also contact us directly or visit the various websites dedicated to providing detailed information on the pest; www.ausveg.com.au is a recommended site to visit.

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