Control strategies for the lucerne flea, Sminthurus viridis (L.) (Collembola : Sminthuridae), and their effect on other species in irrigated lucerne in the Hunter dairying region of New South Wales

The Iucerne flea, Sminthurus viridis (L.), was shown to be capable of causi ng significant yield loss and reductions in percentage lucerne crown cover of stands of irrigated lucerne in the temperate-type climate of the Hunter dairying region of New South Wales, an area previously considered unsuitabl e for lucerne flea establishment. Chlorpyrifos was used in tests of three c ontrol strategies, each of which effectively reduced lucerne flea numbers. Prophylactic sprays in autumn to prevent females of the second generation a fter aestivation from ovipositing gave protection for up to 3 months, but d id not remove the necessity for later treatments. A single application of i nsecticide when lucerne flea was starting to cause severe damage was the mo st effective and economical control strategy but was difficult to time corr ectly. Some other pest and beneficial species were affected by the lucerne flea control strategies and this may have to be considered in pest manageme nt. Strategies for controlling lucerne flea were also capable of reducing n umbers of redlegged earth mites, Halotydeus destructor (Tucker).