Black sunflower scarab larvae are up to 25 mm long, adult beetles are 13 mm long, shiny and black. The larvae of the black sunflower scarab feed on taproots causing wilting and death of plants up to 400mm high. Damage is most prevalent where sunflower crops are planted after wheat, sorghum or grass pasture. Adult beetles feed on foliage, often in large numbers.
Check in the soil for presence of larvae prior to planting
Treat the seed with a recommended seed treatment (Guardian)