The major insect pest of sweet potatoes in Western Australia is the sweet potato leaf miner. This is a small, dark reddish to black grub up to 10 mm long. The adult is a small moth. The grub eats plant tissue between the upper and lower leaf surfaces, leaving a transparent papery 'window' in the leaf. The grub can be seen inside this window.
Heavy infestations can develop quickly, and severely defoliate the crop, reducing yield.
African black beetle African black beetle causes severe damage by chewing holes in sweet potato roots. It is common in crops following pasture. Treatment of the soil before planting with metham sodium will help to control African black beetle. Rutherglen bug Rutherglen bug can appear in large numbers in November and December. The small bugs delay plant establishment.