The banana plant, often mistakenly called a tree, is actually the world’s largest herb. This giant perennial is composed of a soft, watery pseudostem and an underground corm, lacking the protective bark or woody structure of a true tree. Its high nutritional content, from the starchy corm to its sugary fruit, makes it an attractive food source for a wide array of animals. Various pests and grazers, ranging from microscopic insects to large mammals, target every part of the plant, including the roots, stem, leaves, and developing fruit.
Identifying the Primary Animal Threats
The banana plant faces threats from pests that attack its structural foundation, consume its foliage, or steal its yield. The most insidious damage often comes from subterranean and stem attackers that compromise the plant’s ability to stand and transport nutrients. The banana weevil, or corm borer (Cosmopolites sordidus), is a beetle whose larvae tunnel through the underground corm and the base of the pseudostem, causing internal structural decay. This tunneling weakens the plant, making it susceptible to toppling over and can reduce yields by 40% to 100% in severe infestations.
Other ground-based mammals also target the corm and pseudostem base. Rats, gophers, and wild pigs may dig up and chew on the starchy corm, causing direct damage and creating entry points for diseases. Larger grazing animals, such as deer, cattle, and rabbits, primarily consume the tender, young leaves and shoots, which are palatable due to their high moisture and nutrient content. Cattle are known to feed on banana leaves and chopped pseudostems, indicating their attractiveness as forage.
Once the plant produces fruit, a new group of highly mobile animals becomes a concern, focusing on the accessible, high-sugar reward. Birds, bats, monkeys, and squirrels are the primary culprits responsible for yield loss during ripening. Fruit bats are highly attracted to ripening bananas and can cause significant damage overnight. The damage often includes peck marks, partial consumption, or the complete disappearance of individual fruits or hands from the bunch.
Strategies for Controlling Ground-Based Pests
Controlling the most damaging ground-based pests, particularly the banana weevil and burrowing mammals, requires an integrated approach focusing on sanitation and exclusion. For the banana weevil, cultural control is the first line of defense, involving eliminating breeding sites to break the pest’s life cycle. This includes field sanitation, where all harvested pseudostems, trash, and old corms are rapidly destroyed or cut into small pieces to accelerate breakdown. Removing this material prevents nocturnal weevils from finding shelter and places to lay eggs.
Another cultural practice is using clean, pest-free planting material, such as tissue-cultured plantlets, or trimming corms until all discolored tissue is removed before planting. Chemical or pheromone traps can monitor weevil populations, often employing slices of corm or pseudostem to attract adult beetles for collection and destruction. For chemical control, insecticides are typically applied directly to the base of the new plant or as a systemic injection to protect the corm, though this is often reserved for severe infestations. Biological controls, such as entomopathogenic fungi like Beauveria bassiana or specific nematodes, are also used as eco-friendly alternatives to manage weevil populations.
Managing larger ground mammals relies primarily on physical barriers and habitat modification. For subterranean pests like gophers or pigs, burying wire mesh or hardware cloth up to 300 mm below ground level along the fence line prevents them from digging underneath. Standard perimeter fencing deters grazing animals like deer and cattle from accessing the plantation. Removing tall weeds and dense undergrowth around the banana mats eliminates hiding spots for rats and rabbits, reducing their presence.
Protecting the Developing Fruit
Protecting the fruit yield from aerial and highly mobile creatures involves direct, physical exclusion methods once the bunch has formed. The traditional and highly effective method is bunch bagging, which involves covering the entire developing fruit cluster with a protective sleeve. These bags are commonly made of plastic (often blue to aid in ripening) or burlap, and they are secured above the first hand of fruit, hanging open at the bottom to allow air flow. Bagging serves multiple purposes: it physically prevents pests like bats, birds, and squirrels from accessing the fruit, and it traps naturally produced ethylene gas, promoting uniform ripening.
For smaller, backyard plantings, fine mesh netting can be draped over the entire plant or fruit bunch to exclude birds and arboreal pests like squirrels and monkeys. This netting must be tightly sealed at the bottom to prevent entry by climbing animals. Non-lethal deterrents provide a supplementary layer of protection, particularly against birds and cautious mammals. Devices such as motion-activated sprinklers or reflective tape hung near the bunches can startle and discourage pests.