|My canna leaves have holes in them. What type of pests can it be and how can I get rid of them?|
|Cannas are largely free of pests, but the plants sometimes fall victim to canna leaf rollers, or Brazilian skippers (Calpodes ethlius). It is the larva that is known for chewing straight rows of holes on canna leaves. Most types feed as solitary caterpillars, but some feed in groups under a netting of their own silk. Solitary types feed on leaves by rolling, folding, or tying them together before eating them. During the day, they reside on the underside of leaves, and they are active at night. Infested leaves appear shredded from the cocoon-like web made by the leafroller. Young leaves are so damaged, they cannot open and may die. Infested plants are unable to bloom and appear quite ugly. Unless monitored for signs of caterpillars, it is easy to miss the first generation because the caterpillars are already inside tightly rolled leaves below the visible growing point. Second and third generations are more obvious because damage is easier to see and more extensive.
Affected leaves can be cut off and destroyed or unrolled and cleaned (by removing the caterpillar), though some gardeners prefer to use an insecticide. A 3.in.1 rose fertilizer contains a systemic insecticide that will fertilize and help to control insects and worms in cannas.
Slugs and snails are also fond of cannas. They can leave large holes in the leaves, and prefer the tender young leaves that have not yet unfurled. A commercial snail bait such as Sluggo is effective. However, removal of all debris under and around the plants will eliminate daytime hiding places for these nocturnal mollusks, usually eliminating the need for snail bait.
Good luck with your cannas.