Sequestration of plant defenses by spotted lanternfly (Lycorma delicatula) and effects on avian predators

Lycorma delicatula is a polyphagous phloem feeder, which is spreading rapidly in the U.S., and is a major threat to grapes, hops, and ornamentals. Among its hosts, L. delicatula prefers Ailanthus altissima, an invasive tree from which it sequesters toxins, including several quassinoid compounds. We tested how these defenses affected predation by birds of nymphal and adult L. delicatula. Freeze-killed nymphs of each instar were reared with or without access to A. altissima and placed into cups on top of nest boxes occupied by house wrens (Troglodytes aedon). House wrens ate or fed their chicks a greater proportion of L. delicatula nymphs that had not had access to A. altissima than the nymphs that had access to this host plant. Adult L. delicatula reared with or without access to A. altissima were ground up and incorporated into separate batches of suet that were placed into double sided feeders set up at different sites during the winter. Trail camera video was reviewed to record how many times birds pecked each suet cake. Birds pecked the suet containing L. delicatula reared without access to A. altissima significantly more frequently than the suet containing adults that had fed on A. altissima. Of the quassinoids sequestered by L. delicatula from phloem sap of A. altissima, ailanthone and four other quassinoids were identified and quantified in different tissues, with the highest concentrations in the salivary glands. Results suggest that sequestration of toxic chemicals from A. altissima provides some protection to L. delicatula from avian predators.