Population dynamics of banana aphid Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae)

The banana aphid Pentalonia nigronervosa Coquerel (Hemiptera: Aphidae) is the vector of Banana bunchy top virus (BBTV, genus Babuvirus), causal agent of banana bunchy top disease, the most devastating viral disease of banana and plantain (Musa spp). The aphid is present in all the banana growing areas of the world. Field experiments to determine the effect of weather parameters (temperature, rainfall, and relative humidity), and mono- and mixed crop effects on the temporal variation in aphid populations on four Musa cultivars, Essong, FHAI23, PITA 14 and Cavendish Williams, were conducted from April 2010 to January 2013 in Yaoundé, Cameroon. Aphids were counted directly on the pseudostem. Aphid populations were highest during the first year of the study (2010/2011) and were successively lower in 2011/2012, and 2012/2013. The population growth rate was highest on Essong and lowest on Williams, however, temporal pattern of aphid population was similar on all the genotype regardless of the cropping system and time of the year. Apterous population was negatively correlated on FHIA23 under mixed cropping conditions. There was no significant effect of temperature and rainfall on aphid dynamics under both cropping systems, but peak populations on plants coincided with increasing temperatures and decreasing rainfall. No parasitoid was found on banana aphid and predators detected were generalists in the orders of Dermaptera (earwigs), Araneae (spiders) and Coleoptera (coccinelids). Aphid population was generally greater on plantains than on bananas under both cropping systems, indicating Musa genotype is the most important factor that regulates the magnitude of banana aphid population.