Maximizing IPM of Argentine ants and sap sucking pests with biodegradable hydrogels, infra-red sensors, and cover crops

Argentine ant (AA) Linepithema humile, has formed mutualisms with sap sucking pests (SSPs) in citrus, including Asian citrus psyllid (ACP), Diaphorina citri, the vector of Candidatus Liberibacter asiaticus (CLas) that causes the lethal citrus disease, huanglongbing (HLB). HLB is not in commercial citrus. Ants protect 85% of SSPs and 55% of ACP from natural enemies (NEs) and are rewarded with honeydew. AA exacerbates pest infestations. Sprays for AA and SSPs kill NEs, cause secondary pest outbreaks, and increase resistance. Integrated pest management (IPM) of ACP and biocontrol of SSPs can be synergized through three management practices: (1) monitoring AA activity with infra-red sensors, (2) controlling AA with biodegradable hydrogel beads infused with 25% sucrose water and 0.0001% insecticide (plastic liquid bait stations are cost prohibitive), and (3) floral resources that provide food to NEs that attack SSPs. The impacts of orchard wide IPM of AA with sensors, hydrogel beads, and floral resources on biocontrol of ACP and SSPs in citrus orchards will be discussed. Products and strategies derived from this research could be re-appropriated for other valuable cropping systems that suffer greatly from ant-tended pests (i.e., wine grapes and tree nuts), considerably improving biological control across California and upholding its historical precedent of strongly successful IPM programs.