Abstract
Insects perform the greatest part of pollination services (Winfree et
al., 2011) and insects native to a given habitat can play an
irreplaceable ecological role in food webs and plant reproduction
(Travis & Kohn, 2023; Pelmyr, et al., 1996; Suarez, et al.,2000). With
precipitous declines in insect species over the last decades, it is
urgent to document insect assemblages in native plant communities to
support conservation efforts. Identifying pollinators and their
pollination activity is challenging; emerging methods involve the use of
camera traps (Droissart, et al., 2021). In this study, we compare the
accuracy of two different methods of monitoring to produce insect
assemblage of Encinitas Baccharis (Baccharis vanessae): focal
observations and video recordings from camera traps. B. vanessae is a
rare, endemic species found in Coastal Sage Scrub communities in San
Diego County (U.S. Fish and Wildlife Service, 2021). This federally
listed species is threatened by habitat loss and fragmentation, which
may also be affecting the availability of its insect pollinators (U.S.
Fish and Wildlife Service, 2011). Preliminary results indicate that B.
vanessae supports a variety of flower-visiting insect guilds and is in
turn supported by diverse pollinators. While focal observations
underreported insect activity by approximately half, the proportions of
common diurnal visitors were similar with both methods. Camera traps
were unable to provide sufficient detail to discern visually similar
guilds, but were able to record nocturnal insect activity, which was
dominated by moths (Lepidoptera, 82%). While collection protocol in
this study did not record the time an insect spent interacting with a
flower, moths spent notably longer periods in contact with flowers than
most diurnal insects. This study has implications for the effective
monitoring of endangered plant species and their affiliated pollinators.