Transmission of Banana bunchy top virus (BBTV) by multiple clones of Pentalonia nigronervosa Coquerel and Pentalonia caladii van der Goot

Pentalonia nigronervosa Coquerel, and P. caladii van der Goot are sympatric aphid species that colonize sub-tropical and tropical plants in the order Zingiberales and family Araceae including: heliconia, banana, ginger and taro. The two aphid species exhibit differences in host plant use, with P. nigronervosa, the banana aphid, primarily colonizing banana and taro and P. caladii colonizing ginger, heliconia, and taro. Under experimental conditions, we have observed that P. caladii is able to survive and reproduce on banana leaves, with fitness parameters similar to the banana aphid, suggesting these Pentalonia aphids have the potential to colonize banana plants. This evidence leads to the question of whether and to what extent Pentalonia aphids are competent in transmitting Banana bunchy top virus (BBTV) a destructive viral pathogen affecting banana. This study was undertaken to determine the transmissibility of BBTV by 12 clonal lineages comprised of P. caladii and P. nigronervosa each established by a single apterous female kept under continuous parthenogenesis on original host plants. To evaluate BBTV transmission by Pentalonia aphids an assay was developed using excised leaves for acquisition and inoculation of BBTV followed by detection through nested PCR. Third and fourth instar nymphs acquired BBTV from infected banana leaves during an AAP of 4 days, and then transmitted the virus to healthy leaf discs during an IAP of 2 days. Regardless of species and original host plant all aphids were capable of transmitting BBTV to banana leaf discs. This is the first report of BBTV transmission by Pentalonia caladii.