Effects of biotin-binding proteins on eight species of pasture invertebrates

Biotin-binding proteins (BBPs), such as avidin and streptavidin, represent potent insect control compounds which could be delivered via transgenic plants. The effects of BBPs on some pasture pests were determined. Black field cricket nymphs (Teleogryllus commodus) had significantly reduced growth and survival when fed on lettuce leaves painted with purified avidin. Adult clover root weevils ( Sitona lepidus) were unharmed when fed clover foliage painted with avidin. In contrast, neonate or one-weekold S. lepidus larvae had poor survival when fed on artificial diets containing avidin or streptavidin. Neonate larval Argentine stem weevils (Listronotus bonariensis) had significantly reduced survival when fed with artificial diet containing streptavidin or avidin. Slugs ( Deroceras reticulatum) and snails (Cantareus aspersus) were not harmed when fed with avidin-painted lettuce. Similar numbers of eggs were laid and galls produced by the root-knot nematodes, Meloidogyne javanica, Meloidogyne hapla and Meloidogyne incognita, inoculated onto transgenic tobacco plants expressing avidin and non-transgenic controls.