Over the past few weeks a number of growers have raised concerns over yellowing of their cane crops. These crops are showing symptoms which look similar to Yellow Canopy Syndrome (YCS).
However, on close inspection of the crops, an insect known as a Linear bug (Phaenacantha australiae) appears responsible for the leaf effects.
Linear bugs are long slender insects orange to brown in colour and 8-10mm long. They feed by puncturing the leaves and this causes the yellowing and death of the leaf margins.
Figure 1: Linear bug on a leaf of sugarcane.* Figure 2: How sugarcane can appear with linear bugs.
The symptoms are usually found around the edges of the sugarcane fields. There is no need to control these insects as the effects are usually transient and the crops will recover given suitable growing conditions.
(*Figure 1 Image Credit: Samson, P., Limited, B., Sallam, N., & Chandler, K. (2013, January 1). Pests of Australian Sugarcane.)
Figure 2 Image Credit: Evan Shannon.
This article was originally published in the Summer 2023 issue of Farmacist News.