How can I kill curl grub in my garden beds?

Try 'eco-neem'. It's registered for the control of a broad range of chewing and sucking insects including: caterpillars, curl grubs, grasshoppers (wingless), aphids, mites, lawn armyworm, citrus leafminer, whitefly, mealybugs and fungus gnats. Click here for more info or to buy: https://ecoorganicgarden.com.au/products/pest-disease/eco-neem/