The moth Neurostrota gunniella (Gracillariidae) was studied in Mexico and in Australian quarantine to determine its suitability for biological control of Mimosa pigra, an important weed in Australia. Adults lay eggs on the leaves, the first two larval instars mine the leaves and later instars bore into young stems. Neptunia plena is also a host to N. gunniella in the native range when this plant occurs among M. pigra. No other species, of the 14 legume species surveyed in the field near M. pigra infestations, was found to be a host. In laboratory tests, larvae complete development on two species of Mimosa (both weeds) and the four native Australian species of Neptunia. These six species were the only ones accepted by adults for oviposition in no-choice tests. The duration of larval development did not differ greatly among plant species but larval mortality on Neptunia spp. was higher than on M. pigra. Damage to M. pigra plants was much greater than to Neptunia spp. (Davis et al. 1991).

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