Progress towards an IPM support tool for the yellow sugarcane aphid, Sipha flava, in Tanzanian sugarcane

The yellow sugarcane aphid (YSA), Sipha flava, has been a major pest of sugarcane (Saccharum spp. hybrids) plantations in Tanzania since 2016. High peaks of YSA infestation have led to crop losses that are difficult to quantify precisely. An integrated pest management (IPM) plan is being explored following several field visits to sugarcane plantations at TPC Limited in 2019 and 2021. The decision support tool DECIPESTS was adapted for the management of YSA. This required the inclusion of immature sugarcane (from 1 to 4 months old) and the leaf chlorosis symptom, expressed as a causal rule, in the plant physiology rules set, as well as the leaf mosaic virus in the animal (e.g. pest) behavior rules set. The list of natural enemies (parasitoids, predators, entomopathogens) and alternative cultivated and wild hosts were also completed. The agricultural practice rules were improved by considering soil salinity, varieties, rainfall events, irrigation, and water management for YSA infestations. As a result, this work produces a decision tree that distinguishes factors associated with increased YSA damage levels in sugarcane fields and resulting crop losses. This decision tree also presents the events that reduce YSA infestations. Finally, this work can help agricultural managers reduce the use of insecticides, such as the neonicotinoids that are harmful to predators and parasitoids present in the field and known to naturally control aphid populations.