Plant-arthropod interactions of an endangered California lupine.

The reintroduction of endangered plant species is an essential conservation tool. Reintroductions can fail to create resilient, self-sustaining populations due to a poor understanding of environmental factors that limit or promote plant success. Biotic factors, specifically plant-arthropod interactions, have been shown to affect the establishment of endangered plant populations. Lupinus nipomensis (Nipomo Mesa lupine) is a state of California (California Rare Plant Rank: 1B.1) and federally (65 FR 14888) endangered endemic plant with only one extant population located along the central California coast. How arthropods positively or negatively interact with L . nipomensis is not well known and more information could aid conservation efforts. We conducted arthropod surveys of the entire L . nipomensis extant population in spring 2017. Observed arthropods present on L .  nipomensis included 17 families, with a majority of individuals belonging to Thripidae. We did not detect any obvious pollinators of L . nipomensis , providing support for previous studies suggesting this lupine is capable of self-pollinating, and observed several arthropod genera that could potentially impact the reproductive success of L . nipomensis via incidental pollination or plant predation.