First Recorded Observations of Pollination and Oviposition Behavior in (Lepidoptera: Prodoxidae) Suggest a Functional Basis for Coevolution With Joshua Tree () Hosts.

Yucca moths ( spp.) are the exclusive pollinators of Joshua trees ( s. l.). The moths actively pollinate the Joshua tree flowers and lay their eggs in the style. Recent studies have revealed that the plants commonly known as Joshua trees include two distinct, sister-species of plant: Engelm. and McKelvey, each pollinated by two sister-species of yucca moth Riley and Pellmyr, respectively. A number of studies have argued that the moths have coevolved with their hosts, producing a pattern of phenotype matching between moth ovipositor length and floral style length. However, the only known descriptions of yucca moth pollination and oviposition behavior on Joshua trees are observations of made in 1893. The behavior of has never been observed before. We produced the first video recordings of the behavior of , and measured the points of oviposition and egg placement within the floral style. We found a number of differences between the behaviors of and , which appear to be a consequence of differences in floral morphology between and . We also found that variation in floral style length strongly influences the placement of eggs within the flower, which may explain patterns of phenotype matching described previously. However, unlike in other yucca moths, we find that the mode of oviposition is unlikely to wound the floral ovules, and thus that oviposition by is unlikely to prompt floral abscission.