Luckily, we have a climate in most of Georgia which allows us to choose from an array of flowers fitting this description. Two such ornamental beauties happen to be in my landscape. Canna lilies (Red and Yellow King Humbert) and Pineapple Sage are front and center around my aquatic fish pond. Hummingbirds visit the red Canna flowers (and sometimes pause by the variegated ones) throughout a very long growing season and wait patiently until September to enjoy the nectar of the red blooms on the Pineapple Sage. Unfortunately, it appears that such a “good thing” can encourage complacency and the tendency to take things for granted: low maintenance … no worries.
Both flowers are susceptible to pests, which can remain undetected until considerable damage to the plant has occurred and the problem can no longer be ignored. Suddenly, the plants have lost their beauty and we may need help in finding the right solutions. The culprits are Canna Leafrollers and Pineapple Sage Cabbage Loopers.
Cannas are exclusive hosts to two species, the Larger Canna Leafroller (Calpodes ethlius) and the Lesser Canna Leafroller (Geshna cannalis). Both are larvae of the Brazilian Skipper Butterfly and are known by several other common names. Both Cannas are established in the southern United States, stretching from the East to the West coast. The Larger Canna Leafroller is Native to most tropical and sub-tropical regions. In Georgia, their damage is similar and they may coexist in the same landscape. There are two to three generations per year and sometimes all stages of the life cycle are present at the same time. In general, the first stage instar (specific developmental stage of insect larva or anthropod) remains out of sight while it accomplishes the task of rolling the leaf and securing the edges of the roll with a silken thread. The second stage instar remains inside the rolled leaf and unless discovered by discerning eyes, these larvae cause serious damage to the Canna leaves which, as a result, may never unroll to flower or will unfurl with large unsightly holes chewed into the leaf. If no effort is made to remove, manually unfurl, or spray these leaves and larvae in a timely manner, the last generation (pupal stage or time between the developed larva and the adult) will remain in the rolled leaf and will overwinter in this manner until next spring when it emerges as an adult butterfly. The adults will lay clusters of small white-yellow eggs on the upper surface of the leaf. This description of the Brazilian Skipper Butterfly life cycle is general; fine details in this process and the appearance of the damage will help identify which of the two Canna Leafrollers is involved.
Cabbage Loopers on The Pineapple Sage can remain undetected, as well, until damage becomes visible and the plant no longer looks as beautiful as expected. The first signs of the presence of a leaf-chewing pest are black droppings and skeletonized leaves. At that point, detailed inspection of the plant is necessary. The leaves above the droppings may appear with a downward curl, indicating that a pest is present and hiding inside the curl on the underside of the leaf. Various stages of the Looper are present, including first stage larva still in a cocoon or fully developed green caterpillar nearby. In this case, simply cut off the infested leaves, double-wrap in plastic bags, and discard with trash.
It is essential that we take nothing for granted. Prior to purchasing and planting anything in our yards, research about that plant is necessary. Do we have the right environment, climate, soil, sun/shade exposure, and is the plant hardy in our region? Make a plan. Care of the plant after placing it in the ground or in a container, includes regular inspection for possible problems. Make it a habit to take care of yourself while enjoying the beauty of your landscape. Walk through the yard at least twice each week, and inspect every detail of your plants. If you see anything out of the ordinary, seek help. For detailed growing information and help with identification and management of the Canna Leafrollers and the Cabbage Looper, call your Cooperative Extension Office for assistance.
I could have prevented this hard work, had I not been carried away with the beauty and low maintenance of these plants.
Information about Extension Solutions for Homes and Gardens can be found on the University of Georgia Cooperative Extension website, www.caes.uga.edu/extension/cherokee ; or contact the Cherokee County Extension Office, 1130 Bluffs Parkway, Suite G49, Canton, GA, 30114, 770-721-7803. The Georgia Master Gardener Extension Volunteer Program is a volunteer training program offered through county offices of the University of Georgia Cooperative Extension.