progress through three molts to reach adulthood (J3, J4, male and female adults). Reproduction is amphimictic and females can lay up to 1000 eggs. The first molt occurs in the egg and the nematode hatches as a J2. These juveniles undergo anhydrobiosis and become the dormant dauer larvae to withstand the hot summer heat of Australia. Autumn rains rehydrate the dauer juveniles which become active to begin the life cycle over again. Only one generation is produced per year. Host-parasite relationship Infective second stage juveniles colonize plants during the vegetative growth stage and may feed ectoparasitically during this time. When the inflorescence begins to form, the J2s invade the flower ovule and begin to feed endoparasitically. Nematode feeding on floret primordia induces rapid cell division, cell enlargement, and subsequent cell degeneration and collapse. The continuation of this process results in the formation of a large central cavity (in which the now-sedentary nematodes reside) enveloped by a gall wall. Gall size increases rapidly as nematodes grow and reproduce. The gall wall is several cell layers thick. Inner cells of the gall wall (near the cavity) have dense cytoplasm with several mitochondria, indicating high levels of metabolic activity. These cells most likely provide nutrients to the nematodes. The outer layers of the gall wall are unmodified, thereby forming and maintaining the gall structure. As the plant senesces, the galls desiccate and the nematodes undergo anhydrobiosis. Management To mitigate the effects of annual ryegrass toxicity, farmers can move their livestock another, uninfected pasture at first sign of toxicity. Hot water treatments or chemical seed treatments have been used to produce clean seed. Infected pastures can be managed by mowing, herbicide treatments, or burning. These techniques eliminate the development of inflorescences and halt the life cycle of the nematode since they only mature to adulthood within the seed gall. A. agrostis cannot survive in the soil for more than one year and thus practices such as crop rotation or fallow have proven to be effective in managing the nematode. References Agricultural pest nematodes Tylenchida Nematodes described in 1799