Banana bunchy top virus (BBTV)
BBTV is not present in tropical Australia, and the movement of planting material is controlled by legislation. The disease is spread in infected planting material and by the banana aphid. There is no cure for this disease.
Scientific name (Pentalonia nigronervosa )
Description of adults
Small reddish-brown to almost black oval shaped aphids. Aphids have two characteristic projections from the rear of the abdomen. Colonies of adult and immature stages are found on the pseudostem (of banana plants) under the leaf bracts and between the bunch bracts and the branch stalk. Colonies can also be found in the unfurled top leaves of young plants and suckers or under leaf bases near ground level. Winged forms have prominent forewings with dark pigmented veins.
Nymphs resemble adults but are slightly smaller and do not have wings.
Ants often attend colonies of winged (alates) and wingless (apterous) aphids. Ants assist in the spread of aphids and feed on the honeydew. Spread of colonies also results from short or long distance migration of alates during warm days. Mature females produce live young that develop into alate or apterous adults depending on weather, aphid density and host conditions. In Australia reproduction is probably asexual throughout the year. Specific lifecycle details are not available however aphid numbers can build up rapidly under warm conditions and in the absence of parasites and predators.
Present throughout Queensland.
Banana is the main host but other hosts include Manila hemp, Heliconia spp., Caladium, Diffenbachia, ginger and other members of the Musaceae, Araceae and Zingiberaceae families.
Banana aphid is a minor and frequent pest in northern Queensland where bunchy top does not occur. A more serious pest in south-east Queensland because it is a vector of bunchy top disease.
Direct feeding damage is uncommon. Damage from excessive honeydew and the resultant sooty mould development occurs only rarely and only when populations build up to high levels. The greatest potential damage is due to transmission of bunchy top virus in southern Queensland. Because of this the aphid is regarded as a serious pest in that area. The virus is not present in North Queensland.
Chemical control of aphids is not effective for bunchy top control and direct damage is seldom severe enough to warrant treatment.
Natural predators such as ladybird beetles, hoverflies, earwigs and lacewings usually maintain low aphid populations.
Spray only if aphid problem is severe. Avoid regular spraying as this will remove beneficial insects and may induce other pest problems.
Chemical registrations and permitsCheck the Australian Pesticides & Veterinary Medicines Authority chemical database and permit database for chemicals registered or approved under permit to treat this pest on the target crop in your State/location. Always read the label. Always observe withholding periods.Source: DAFF
Published: Zarai Media Team