Like other parasitic wasps in the family Ichneumonidae, the adult female L. luteolator uses its ovipositor to lay eggs inside the body of its prey, usually the larval stage of a sawfly larva, often a leaf miner.

Various sawfly larvae are attacked including the red oak leaf miner (Profenusa alumna).

[3] In Alberta, the host is the "pear slug" (Caliroa cerasi), which is not a mollusc but the larva of a sawfly.

[2] However, in Alberta in the early 1990s, the wasp adopted a new host and started parasitising the amber-marked birch leaf miner (Profenusa thomsoni), an invasive species that had appeared in the province twenty years earlier and become a major pest of birch trees (Betula).

A dramatic collapse in populations of the leaf miner followed, and numbers remain low, seemingly kept under control by the parasitic wasp.