sustainability through science & innovation

Other crop establishment pests

Lucerne fleas, Balaustium mites, millipedes, slaters and slugs are still causing issues in many regions.

 

Latest reports

Lucerne flea

Growers report that lucerne flea (Sminthurus viridis) impacts in numerous crops near Walla Walla in the NSW South West Slopes are as damaging as they were 25 years ago in the severe seasons of 1988 and 1989. At Donald in Victoria’s Wimmera, lucerne fleas are causing significant damage to germinating grain legumes and cereals. Up to 25% of barley plants have been affected. Lucerne flea numbers have also been extremely high around Elmore, in Victoria's Northern Country. See PestFacts Issue No. 2 for more details on lucerne flea.

 

Balaustium mites

Balaustium mites (Balaustium medicagoense) have retarded the growth of a number of young canola crops (cotyledon to 1st true leaf) in the Bacchus Marsh region of Victoria’s Central District. The cotyledons have become leathery and cupped, which is typical of Balaustium feeding damage. Mite numbers were not particularly high. Prior to sowing, the paddock had moderate areas of rye grass and other weeds, which presumably acted as a ‘green bridge’ for the mites. See PestFacts Issue No. 3 for more details on Balaustium mite.

 

Millipedes and slaters

Millipedes and slaters have caused significant damage to several canola crops in the Dookie, Devenish, Bungeet and Thoona areas of Victoria’s Northern Country District. In circumstances similar to those reported in PestFacts Issue No. 3, surprisingly, some damaged paddocks had been burnt prior to sowing. Burning is expected to reduce population sizes of these pests. In other crops, very large numbers of millipedes were found under stubble but no significant crop damage had occurred. Slaters have been reported to be causing some damage to canola crops sown into cereal stubbles around Forbes, in the NSW Central West Slops & Plains. In the Wagga Wagga area of the NSW Riverina, millipedes have been observed sheltering in large numbers under stubble, although in the emerging crop, there were no signs of damage. See PestFacts Issue No. 1 for more details on these pests.

 

Slugs

Several canola crops in the Elmore area of Victoria’s Northern Country have been damaged by various pests, but predominantly slugs. The plants’ hypocotyl have been ringbarked or chewed at the ground level. Damage is noticeably lower in soil compacted by tyre tracks. While slaters were present in very large numbers, a night inspection revealed that most damage was caused by slugs. In Victoria’s Western district, slug damage to canola and wheat crops appears to be the worst in 3 years. In unbaited crops, the slugs have chewed off canola stems and hollowed out germinating wheat seed. Although the main species is the grey field slug (Deroceras reticulatum), more black keeled slugs (Milax gagates) are being detected this year. A whole-paddock trial recently conducted has shown a substantial reduction in slug damage in areas with a deep cultivation prior to sowing as opposed to sowing directly into standing stubble.

In the Urana to Yerong Creek area of the NSW Riverina, slugs have also been damaging canola crops. Interestingly, slugs appear to be worst in areas sown with a prickle chain instead of press wheels. Slug expert, Michael Nash (SARDI), says monitoring using tile refuges has not been practical in some regions because the soil surface has dried out. See PestFacts Issue No. 1 for more details on slugs.

 

* Sources of field reports

Lisa Castleman - Agronomist, NSW DPI (NSW South West Slopes)

Craig Drum - Agronomist, Tatyoon Rural (Victorian South West)

Chris Dunn - Agronomist, Landmark (Victorian Northern Country)

Eoin Flett - Agronomist, Young and Jackson (Victorian Central District)

Heidi Gooden - Agronomist, Delta Ag (NSW Riverina)

Bruce Larcombe - Agronomist, IK Caldwell (Victorian Central District)

Rik Maatman - Agronomist, Landmark (Victorian Wimmera)

Michael Nash - Researcher, SARDI (Adelaide)

Greg Toomey - Agronomist, Landmark (Victorian Northern Country)

PestFacts is supported by