Some species in the tree genus Macaranga (Euphorbiaceae) in the Southeast Asian tropics are myrmecophytic; they have highly species-specific mutualisms with symbiotic ants (plant-ants), which defend them from herbivores. However, larvae of some Arhopala (Lycaenidae, Lycaeninae) species can elude the ants. Here we demonstrated that Arhopala zylda larvae showed myrmecoxeny on their myrmecophytic Macaranga host plants; they had no stable association with the plant-ants. Despite the presence of many plant-ants, A. zylda larvae were rarely attended or attacked by ants on their host plants. The plant-ants of three other myrmecophytic Macaranga species (non-hosts to A. zylda) also paid little attention to experimentally introduced A. zylda larvae. The myrmecoxeny seen in A. zylda is notable among lycaenid larvae that feed on myrmecophytes, because almost all are obligate intimate myrmecophiles.