such as the bigheaded ant (Pheidole megacephala
) and Tetramorium
spp. are important predator
s of the banana weevil. Although these ants are generalists (feed on a wide variety of food materials such as nectar, sugar, honeydew, other insect substances with high fat content, etc.) high populations in banana stands make them very efficient predator
s. They will enter crop residues and living plants in search of weevil eggs, grubs and pupae. These ants have reportedly contributed to the successful control of banana weevil in plantain in Cuba. These ants can be encouraged to nest in pseudostem pieces that can then be used for further distribution. They are widespread and may also be important predator
s on the weevil in other localities. Studies in Tanzania and Uganda have shown that several species of ants are important natural enemies
of the banana weevil in the region (Aberra, et al, 2007, A. M. Varela, icipe, personal communication).
Some fungi (e.g. Beauveria bassiana and Metarhizium anisopliae) have shown efficacy as control agents of this pest. Some of them caused weevil mortality of over 90%. In Cuba, the fungus Beauveria bassiana is reported to be effective against the banana weevil in combination with ants (CABI, 2000). However, there is little information on the performance under field conditions. Moreover, the distribution and application of these biocontrol agents are still restricted by lack of facilities and high costs.
Some nematodes, (Steinerma and Heterorhabditis spp.) attack both adults and grubs in the field, but economic cost and their efficacy limit their use on a large scale (Gold and Messiaen, 2000).