Did you know a spring spray is very effective in controlling REDLEGGED EARTH MITES, to prevent damaging populations emerging next autumn?


Key points:

  • Spray in spring to control autumn outbreaks
  • Remove females before summer egg laying
  • October 16th ideal spray date for our southern Victorian customers
  • Wet springs, like this season, ideal conditions for populations to flourish

In spring RLEM lay diapause eggs which are extremely tough, surviving hot summers, and hatching when cooler, wet conditions arrive in Autumn – often causing significant damage to new pastures.

With the help of the Timerite model, a AWI funded CSIRO program, farmers can predict the best date for spring spray, to control redlegged earth mites the following autumn.

FOR EXAMPLE
POOWONG: 16th October
Latitude:38°20′
Longitude:145°44′

Using the Timerite spray date will remove females before they produce their eggs, significantly reducing the number of mites hatching the following autumn.


What is typical damage of Redlegged earth mite?

Sap sucking RLEM are most damaging to newly establishing pastures including clover and lucerne crops, greatly reducing seedling survival and development. It’s important minimise populations in spring so that autumn sown seedlings have an opportunity to emerge

In spring existing pastures, typical damage appears as silvering or whitening of the attacked foliage, reducing production

Autumn sown pastures, especially those containing emerging clover and lucerne are at risk with Redlegged earth mite feeding by piecing plant cells and sucking out contents.

Redlegged earth mite damage. Whitening of foliage, reducing pasture production potential

Why spray in spring?

For a short time in spring, after RLEM have finished laying normal winter eggs on the pasture, but before they produce their oversummering eggs, there are minimal eggs present. This is the ideal time to spray because eggs are impervious to sprays, and so the whole population is vulnerable.

However control is not 100% effective and very low populations survive to the following autumn.


High risk redlegged earth mite situations

  • Dense pasture canopy, ideal for mites.
  • Abundance of broad leaved weeds like capeweed and marshmellow.
  • Susceptible pasture or crop plants will be present next autumn, i.e. clover pastures
  • If there is good soil moisture at the time of the Timerite spray; which will probably mean an extended spring growing season and more oversummering mite eggs.
  • You’ve had redlegged earth mite activity in the past.

What do redlegged earthmite look like?

Adult mites are about 1mm long and 0.6mm wide. Younger mites are smaller with a black velvety body and eight red legs.


When is the right time to spray?

Regular paddock monitoring is of importance in spring time as redlegged earth mite is in action.

Optimum dates for redlegged earth mite control in eastern Australia are mostly between mid-September to mid-October. The date for spring spraying is unique to each property and remains constant from year to year.

Get in touch with Notman Pasture Seeds for advice on the right time to spray, call on 03 5659 2314

Using the TIMERITE program the most appropriate spray date predicted by the TIMERITE® model, developed by the CSIRO is:

Southern Victoria

POOWONG: 16th October
Latitude:38°20′
Longitude:145°44′

LEONGATHA: 16th October
Latitude:38°29′
Longitude:145°57

PURNIM: 16th October
Latitude:38°17′
Longitude:142°35′

MAFFRA: 16th October
Latitude:37°58′
Longitude:146°59′

BALLARAT: 16th October
Latitude:37°33′
Longitude:143°51′