Onion Thrip 

Symptom

It extends from the early growth stage of the plant to the point of harvest. Thrips feeding creates silver or white streaks and spots on leaves as they pierce plant tissues and suck out sap. Initially, injury is difficult to detect, due to the concealed location of the thrips. A close look between the leaf sheaths is necessary to locate active thrips or leaf injury. In severe cases, leaves may become white or straw-coloured appearance, starting from the tips. Damage can cause leaves to become wrinkled, curled, or twisted. During hot, dry seasons, damage from thrips becomes most serious and may result in reduced onion yields. Feeding also puts added stress on the plant, making the onion more susceptible to bacterial rot and fungal attack.