Opogona sacchari
(banana moth)

O. sacchari was originally described from specimens from Mauritius. It is a tineid moth with typically Old World tropical distribution, thus populations could establish in the tropical belt and in areas with a mediterranean climate, also in glasshouses throughout the world. O. sacchari attacks a number of ornamental plants and can be transported on different plant parts. Although not listed on alert lists such as IUCN and ISSG, this species has the potential to be invasive outside its natural distribution area through the transport of ornamental plants and/or because of global warming.

O. sacchari, originally on the EPPO A1 list (OEPP/EPPO, 1988), has been on the A2 list since its establishment in Italy. CPPC and NAPPO also regard it as a quarantine pest.

It has been accidentally introduced on many occasions in recent years (usually among imported bananas) into South America, Europe and Egypt.

The pest could acclimatize in more temperate regions on several ornamental plants, especially those of tropical origin. Trade in ornamental plants carries a serious risk to the distribution of this species.

O. sacchari is a troublesome greenhouse pest that should not be allowed to establish in new areas; fortunately, it can be controlled and has not yet established outdoors.
 

In general O. sacchari is a scavenger in dried/harvested vegetable material. It prefers to attack plant tissue damaged through other causes and then spread to living healthy plant tissue (Heppner et al., 1987). In the wild, the abundance of the pest varies significantly with the amount of rainfall, infestation being markedly heavier in years with reduced rainfall than in those with abundant rainfall (Sampaio et al., 1983). In bananas it attacks the fruits, pseudostems, peduncles and 'cushions', being especially abundant in decaying pseudostems (Cintra, 1975).
 

O. sacchari is found mainly in the tropics on bananas, pineapples, bamboo, maize and sugarcane in the field and on various stored tubers. In glasshouses in European countries, it has been found infesting various tropical or subtropical ornamentals, including mainly Cactaceae, Dracaena, Strelitzia and Yucca, but also occasionally Alpinia, Begonia, Bougainvillea, Bromeliaceae, Chamaedorea and other palms, Cordyline, Dieffenbachia, Euphorbia pulcherrima, Ficus, Gloxinia, Heliconia, Hippeastrum, Maranta, Philodendron, Sansevieria and Saintpaulia, and also Capsicum and aubergines. In import inspections, it is mainly Dracaena and Yucca which have been found to be infested.

The larvae are scavengers of dried/harvested vegetable material. This species may attack stored tubers (Gibbs, 1991) and feed occasionally on living plant material when adjacent to dried vegetable matter.
 

At 15°C, the life cycle of O. sacchari lasts ca 3 months: the eggs hatch in 12 days; larval development requires 50 days; the pupal stage lasts 20 days; and the adult lives for 6 days (Veenenbos, 1981). This period may be considerably reduced under warmer conditions, allowing up to eight generations per year (Giannotti et al., 1977; Heppner et al., 1987). At 25°C and 10% RH, the pre-oviposition period was 2.7 days, the oviposition period lasted 5.9 days; and 81.65 eggs were laid per female. The larval and pupal stages lasted 24.19 and 11.24 days, respectively. The complete life cycle from egg to adult took 37.91 days (Bergmann et al., 1995).

The female lays eggs in crevices in plant tissue, in groups of about five 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 voracious.

In banana, the fruiting head is normally infested (Suplicy and Sampaio, 1982), but in ornamental plants the larvae mostly burrow in the stem (woody or fleshy plants such as cacti, Dracaena) or sometimes leaves and petioles (Begonia, Saintpaulia). Seedlings may be severely attacked (D'Aguilar and Martinez, 1982).

As a tropical pest, O. sacchari cannot apparently survive outdoor conditions in winter over most of the European and Mediterranean region. Its presence in the Atlantic Islands of Portugal [Madeira] and Spain [Canary Islands] suggests that it might survive in parts of the Iberian peninsula and North Africa. Billen (1987) has reviewed the taxonomy, biology, distribution and control of O. sacchari and refers to the existence of several species with similar biology in Africa, possibly to be regarded as members of the same complex.
 

There are no known natural enemies of O. sacchari. A successful establishment of the nematodes Steinernema feltiae, Heterorhabditis bacterophora and H. heliothidis in greenhouses was reported from Italy in the eradication of larvae of O. sacchari infesting potato and bamboo palms (Chamaedorea elegans) (Pena et al., 1990).
 

Larval infestations in the early stages are practically undetectable. At a later stage fleshy plants may be completely hollowed out. In woody plants infested tissues may feel soft. At a later stage frass may be detected on the infected plant tissues or beneath the plants. Dead leaves lie underneath the plants.

On ornamental plants, O. sacchari is difficult to intercept at importation inspections, additional post-entry inspections are recommended.

On Strelitzia species, the larvae fed on the collar and roots of the plants (Porcelli and Parenzan, 1993).
 

Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

Environmental manipulation techniques offer a suitable alternative for quarantine procedures.

Thermal control experiments were carried out exposing Dracaena fragrans stems to 44°C. Exposure of 45 minutes had no effect on propagation and 60 minutes had no permanent damage to foliage. Mortality of insects was related to thermal exposure. Few larvae survived 15 minutes of exposure and no larvae survived 30 minutes (Hansen et al., 1997).

Inundation techniques were discussed by Cheek (1994) for propagation material.

Eradication in greenhouses by chemical treatment and sanitation has proved possible in several northern European countries, but not in Italy, where the pest is established in greenhouses. The adult moths can be controlled by fogging with permethrin. The aim is to kill all adults before they can lay eggs. When an affected greenhouse is cleared and replanted, the soil should be steamed (or removed) to eliminate any residual pupae. Billen (1987) has reviewed the chemical control methods tried out in greenhouses in various European countries. Gianotti et al. (1977) suggests that chemical control measures might be most effective if applied between 20.00 and 24.00h.

Sex pheromones are being studied in Italy (Rotundo and Tremblay, 1982) and Brazil (Ioneda et al., 1983).

Yam tubers (White Lisbon) were treated in Barbados by dipping the tubers in a solution of carbaryl or by covering the tubers by lime and/or ash (Gibbs, 1991).

Banana fields in Brazil were dusted with several combinations of insecticides. The dusting method was significantly better than the spray method (Pigatti et al., 1982). There seems no significant amount of residue present in the skin or flesh of bananas using the dusting method (Guindani et al., 1978). 

The taxonomy of Opogona species requires clarification. The genus belongs to the Hieroxestinae. According to Robinson and Nielsen (1993), there are about 270 known species but this number could rise to 300, with many undescribed species held in museums, most belonging to the genus Opogona. This means that the species currently identified as O. sacchari belongs to a species complex for which correct identifications do not yet exist. It is possible that several unnamed species could be introduced at this stage.

22/11/2007 Updated by:

Koen Maes, Consultant, Belgium