English names: Banana moth Nordic names: Bananmøl (DK)
Major host plants
In glasshouses Opogona sacchari can infest various tropical or subtropical ornamentals, including mainly Cactaceae, Dracaena, Strelizia and Yucca. However, many other ornamental plants can be attacked. In the tropics, O. sacchari is found mainly on banana, pineapple, bamboos, maize and sugarcane in the field and on various stored tubers.
In ornamental glasshouse plants, the larvae mostly burrow in the stem or sometimes leaves and petioles. Seedlings may be severely attacked. The leaves of the host wilt because the caterpillars destroy the xylem. Heavily infested stems are completely mined with tunnels and plants may collapse. Characteristic masses of bore-meal and frass deposits can be found at the openings of bore-holes.
In banana, the fruiting head is normally infested.
Opogona sacchari originates in the humid tropical and subtropical regions of Africa. It was introduced into the Canary Islands in the 1920´ s, into Brazil in the 1970´s and later into North America and Europe.
A map can be downloaded from EPPO´s website. See instructions here.
The female lays eggs in crevices in plant tissue in groups of about 5 eggs, 50-200 in total, by means of a long ovipositor. The larvae, which burrow in the plant tissue, are extremely mobile and avoid light. They are very greedy. At 15 0C, the life cycle of O. sacchari lasts approximately 3 months: eggs hatch in 12 days; larval development requires 50 days; the pupal stage lasts 20 days; the adult lives 6 days. This period may be considerably reduced under warmer conditions, allowing up to 8 generations per year.
O. sacchari can disperse itself by flight within glasshouses or over short distances in the field. In international trade it is liable to be carried in propagation material of host plants, for example cuttings of Dracaena. Because of the wide variety of host plants, many plant species may carry either eggs or larvae.
Detection and inspection
Egg: The eggs are very small and extremely difficult to detect.
Larva: The caterpillars of O. sacchari are dirty-white and somewhat transparent. They have a bright reddish-brown head and clearly visible brownish thoracic and abdominal plates. The larvae are very mobile and measure 26–35 mm in length with a diameter of 3 mm for the last instar.
Pupa: The pupae are brown and less than 10 mm long and are formed in a cocoon, spun at the end of a feeding chamber/larval tunnel, measuring 15 mm. Two bent hooks, characteristic of the species, are visible at the end of the abdomen.
Adult: The adults are nocturnal moths, 11 mm long with a wingspan of 18–25 mm, and bright yellowish-brown. The forewings may have longitudinal darker brown bands. The hindwings are paler and brighter. At rest, the long antennae point forwards. They can be monitored with feromone and light traps.
The early stages of larval tunneling in woody or fleshy stems are practically undetectable. The presence of older larvae can be detected by the characteristic masses of bore-meal and frass deposits. Empty pupal cases can often be found projecting out of bore-holes after the adults have emerged. In holes with frass, the excrements of young larvae are fine and crumbly, those of old larvae look like pellets.
Pest status and importance
O. sacchari is causing significant losses in many crops, especially in glasshouses and in tropical cultivations. O. sacchari could be a threat to the increasing production of bananas under polythene in Morocco and Spain. Elsewhere in the Europe, O. sacchari primarily presents a risk to woody or perennial ornamentals grown in glasshouses and could not survive outdoors.
Source of information
See further information here:
Author: Jorma Rautapää
Editor: Dorthe Vestergaard