Canna Bugs

Leafrollers are common canna pests.

Flowering canna are often found in home gardens and in the commercial landscape. These lovely flowers are easy to grow and develop few damaging diseases. However, flowering canna is susceptible to infestations of the canna leafroller, which is a leaf-chewing insect. Two types of canna leafrollers damage canna, the lesser canna leafroller and the larger canna leafroller. Both caterpillars are destructive to canna, causing significant damage.

Identification

The larger canna leafroller and the lesser canna leafroller infest primarily canna and arrowroot.The larger canna leafroller is also known by the scientific name Calpodes ethlius and is a lime green caterpillar. The lesser canna leafroller is known by the scientific name Geshna cannalis and is a yellow-colored caterpillar. These damaging caterpillars are seen in the spring through the late fall and can continue to damage canna if the winter is mild and plants produce new foliage.

Types/Effects

Canna leafrollers most often attack members of the Cannaceae family, as well as West Indian arrowroot or Maranta Arundinacea L. Leafrollers feed on the insides of canna leaves, causing the leaves to develop a rolled-up appearance. Feeding on canna leaves may cause severe damage, causing host plants to delay flowering.

Cultural Controls

Cultural controls are important in the control of the larger canna leafroller, as well as the lesser canna leafroller. Accomplish proper sanitation by removing all infected debris from the garden and destroying it after frost damage has killed back foliage. Keep your garden free from weeds, which can host many types of insects.

Chemical Control

Chemical control products are available for the control of leafrollers. Spraying products with the active ingredient Bacillus thuringiensis or BT on canna is often effective in controlling young leafroller larvae. Other insecticidal sprays or dusts containing Carbaryl are also effective in leafroller control. Thoroughly cover canna foliage with insecticides, as contact with pests is necessary for successful control.

References

• Texas A&M: Canna Leafroller: Kim Ethridge, Camille Goodwin
• University of Florida: Larger Canna Leafroller, Calpodes Ethlius: Heather J. McAuslane, Kim King