Do you have Redlegged Earth Mites?

The first step in managing your RLEM is to determine whether you actually have RLEM or whether you have a different mite.

What Are Redlegged Earth Mites?

RLEM (Halotydeus destructor) is an introduced pasture and crop pest in southern . It is estimated that RLEM infest 20 million ha of pasture, causing $200 million damage to the wool industry alone.

What Do They Do?

RLEM feed on the upper surface of plants. They can kill emerging clover seedlings; suppress seedling and adult plant productivity and reduce pasture palatability and digestibility.

Find out more about the damage caused by RLEM

What Do They Look Like?

Adult RLEM are 1mm long and 0.6mm wide. As their name suggests, they have red legs and their bodies are completely black and velvety. Newly hatched mites are pinkish/orange with 6 legs, are only 0.2mm long and are not generally visible to the naked eye. The nymphal stages have 8 legs and resemble the adult mite, but are smaller.

RLEM look very similar to Blue Oat Mite, another common pasture pest. The biology and lifecycle of RLEM and Blue Oat Mite are very different. Management options targeted at RLEM will not necessarily control Blue Oat Mite. This is especially the case with Timerite®. It is important to know the difference between RLEM and Blue Oat Mite.

Find out more about the differences between RLEM and Blue Oat Mite

How Do I check if I have RLEM?

It is best to check whether you have RLEM before you spray in either autumn or spring.

To check for RLEM in autumn, you need to wait for the mites to develop into adults so that they are visible to the naked eye. The mites emerge from oversummering eggs when the mean maximum daily temperature drops below 21.5°C for a period of 7-10 days. This also has to coincide with a significant rainfall event.

After these weather conditions have been met, mites will begin to emerge within 7-10 days. However, the mites will be very small (~0.2mm) when they first emerge, so you’ll have to wait 2 weeks before going into the field to look. But make sure you bring a magnifying glass as the mites will still be very small.

In spring, make sure you check for mites before your Timerite® date. If you didn’t spray on your Timerite® you may notice mites present after your Timerite® date. However, these mites will already have already produced over summering eggs which will survive a pesticide spray.

Before you go into the field to check for RLEM:

1. Print out copies of the RLEM Pasture Check sheet to take with you into the field. You’ll need one copy per paddock. The sheet contains step by step instructions on how to check for RLEM and space to record your observations.
2. Make sure you take a pencil for recording what you see.
3. The mites are very small (1mm) so if you need glasses, make sure you have these with you. Even if you don’t need glasses, you may like to take a magnifying glass with you to help you identify the mites.

Download your RLEM Pasture Check sheet (PDF 24Kb)