Adults and nymphs are yellow-green, wingless and globular in shape. They can have dark markings. They hop or spring when disturbed. Adults are 2 mm long.
Feeding damage on pasture legumes can be confused with redlegged earth mite damage.
Originated in Europe, now found worldwide. In Australia the lucerne flea is an established pest in southern agricultural areas of South Australia, Tasmania, Victoria and Western Australia. It has recently been recorded as a pest in New South Wales.
Major, widespread, regular.
Lucerne, canola, wheat, barley, tricticale, oats.
Young nymphs feed on the soft tissue of leaves leaving transparent windows. Adults and older nymphs chew irregular holes in leaves and can completely defoliate plants.
Autumn - spring, but particularly at germination.
Six generations a year between autumn and spring. The number of generations and length (may vary from 3-5 weeks) of each generation is temperature dependent. The first generation develops from oversummering eggs after the onset of favourable moisture and temperature conditions, usually around April. The last generation of females lays oversummering (diapause) eggs on the soil surface that do not hatch until favourable conditions return the following autumn. In mid to late spring lucerne fleas die with the onset of warm dry weather, leaving oversummering eggs on the soil surface. To protect eggs from desiccation and heat, the female covers the eggs with excreted clay soil and fluid.
|Monitoring and action level|
Inspect regularly for damage, which can be patchy especially during establishment.
If lucerne flea regularly causes damage, seed-dressing insecticides should be applied when sowing or reseeding pastures. If damage warrants control, spray pastures about three weeks after the eggs have hatched in autumn. At this time all the oversummering eggs should have hatched and the first generation females will not have started laying eggs. A follow-up spray may be required. For current chemical control options see Pest Genie or APVMA.
Natural enemies: In south-eastern Victoria, Tasmania and southern Western Australia, an introduced predator, the spiny snout mite, Neomolgus capillatus, significantly reduces lucerne flea numbers in pastures. In Western Australia, the pasture snout mite, Bdellodes lapidaria, is an effective predator.
- Pests of field crops and pastures: identification and control, editor P T Bailey.