Slaters

Growers in the Central West of NSW have experienced crop loss from slaters.

 

Where have they been reported?

Growers in the Coolah area in the Central West Slopes & Plains district of NSW have experienced considerable problems with pests that appear to be slaters (Thanks for the reports!*). A range of crops has been attacked including lucerne and oats (2-3 leaf stage), with the lucerne crop suffering extensive damage. The affected paddocks were often associated with minimum or no tillage and stubble retention. The slater species responsible for these issues has not been confirmed.

Slater habits and behaviour

Slaters can attack broad-acre crops, and in some instances can cause serious damage. Slaters typically feed on decaying organic matter and only rarely feed on emerging crop seedlings. Their presence is always associated with moist soils. There appears to be a strong correlation with minimum tillage and stubble retention. Stubble provides a cool, moist refuge that enhances survival and population development. Crumbly clay soil surfaces and cracking clays also seem to favour the survival of slaters. Slaters need damp conditions and will die if exposed to open and dry situations.

In the past, we have received reports of slaters causing damage to cereals, canola, lentils and pastures in many parts of NSW and Victoria. Feeding results in uneven rasping-type damage that often appears as ‘windows’ of transparent leaf membrane. Alternatively, they have been associated with seedling damage where the hypocotyl is cut at the soil surface. However, the presence of slaters within a paddock, even in high numbers, does not necessarily mean a pest issue. The trigger that switches their feeding from decaying organic matter to living plant matter is unclear.

Our advice

Management options are limited after crop emergence so prevention is a key part of control. Managing stubble is likely to be the most effective strategy to reduce slater numbers. Some growers have had success managing slaters ahead of canola rotations through burning crop residues.

Control options

There are no insecticides registered against slaters in broad-acre crops, and previous reports indicate that, in some circumstances they have been relatively unaffected by foliar sprays of both synthetic pyrethroids and organophosphates applied to control other crop establishment pests. There are chemical baits registered for use against slaters in horticulture, and reports suggest some success with chlorpyrifos baits in Western Australia.

 

* Source of field reports of slaters

Ed Blackburn - Agronomist, Haynes Farm & Hardware (NSW Central West Slopes & Plains)