Plant Visitor Observations
One monitoring plot was established per colony (n = 3). Each plot was 8m × 8m and contained 22 - 96 L. nipomensis individuals. Arthropod visitor surveys were conducted by two observers every other week from March 2017 to May 2017 for 40 minutes per observer per plot (48 hours total across all plots). Short observation times and single field season were due to limited accessibility, small population size, and the permitting protocol to access private property. It is important to note that not all flower visitors are pollinators, but they are considered potential “incidental pollinators”; incidental pollinators move pollen from flower to flower while foraging for other resources (Kearns, Inouye and Waser, 1998; Anandhan, Kazmi and Dey, 2020). Diurnal insects are most active during the warmest time of the day, which corresponds with peaks in flower nectar resources (Willimer, 1983) observations occurred between 12:00 – 15:00 to observe the greatest potential suite of insects visiting L. nipomensis (Herrera, 1990). One set of early and late sampling (beginning at 9:00 and 16:00, respectively) were conducted to increase the likelihood of sampling temporal niche visitors. During each collection we also classified cloud cover on a 4-point scale and ambient air temperature.
Insect samples were collected using aspirations, beat samples, hand or net collections, and flower collections for floral dissections. Nets were only used when necessary to minimize damage as dictated by the California Department of Fish and Wildlife collection permit (Scientific Collecting Permit SC-13574). Beat sampling was conducted on every individual in the plot during each observation period. Field flower samples were stored in air-tight bags with an ethyl acetate cotton ball and kept cool until returned to the lab. Flowers were then dissected and any arthropods found were placed in 75% ethanol vials. Specimen collection complied with California State and Federal laws and samples were vouchered at the Invertebrate Zoology Collection at the University of California, Santa Barbara (Appendix 1 ).
Insects were identified to family and received lower classifications if possible (Carvalho, 1955; Herring, 1976; Slater and Baranowski, 1978; Schuh and Slater, 1995; Gibson, Huber and Wooley, 1997; Ross, Thomas and Skelley, 2002; Daniel and Franz, 2012; Hoddle, Mound and Paris, 2012; Marshall, 2012; Iowa State University Department of Entomology, 2017). Specimens identified to family were sorted into putative species based on morphology, or morphospecies (Samways, McGeoch and New, 2010). New host records were determined and recorded via the Global Biotic Interactions (GloBI) database and through literature searches (Poelen, Simons and Mungall, 2014). Families classified as flower visitors are considered potential pollinators and were observed on or in flower parts of L. nipomensis .