In 2010, we initiated research on pollinator habitat gardens (hedgerows) in 8 stone fruit orchards in Brentwood, in northern California. One goal was to install native and non-native plant species in linear gardens to attract native bee species, which we used successfully statewide (Frankie et al., 2005, 2009, 2014). Our 2010-2018 Brentwood research demonstrated that planned hedgerows attracted diverse native bee taxa (144 species), and that many species (23) also visited a variety of crop flowers (Frankie et al., 2018). In our current study, we applied these past experiences to avocado orchards in southern California to examine avocado flower visitors in installed habitat gardens, or hedgerows. Gardens were installed in 3 avocado orchards in Santa Barbara and Ventura Counties to evaluate native bee diversity and abundance between hedgerows (treatment sites) and surrounding orchards and wildlands (control sites). Native bees and Western honey bees (Apis mellifera) were monitored at each orchard over 6 years from 2014-2019, with supplemental collections done in 2020-2021. Hedgerow sites had greater bee species diversity, and slightly greater bee abundance. At the 3 orchards, 105 bee taxa were recorded from standardized monitoring periods during avocado flowering season (March-May). Honey bees were found to visit many hedgerow plants, and avocado growers indicated the importance of having floral resources year-round for the bees. ‘Lisbon’ lemons are often grown in close proximity to avocado trees, and control of Citrus pests, especially the Asian citrus psyllid, was factored into variables impacting avocado visitors. At least 60 insect taxa were recorded visiting avocado flowers. Half of these were native bee taxa, and the rest were flies (especially syrphids), wasps, and beetles. Factors impacting long-term bee monitoring results included unusual weather conditions, wildfires, and possible pesticide drift. Frequent communication with growers was critical for sharing findings, collaborating in plant installations, and addressing questions.

Dryland wheat farming commonly uses a rotation of wheat to fallow between years but growers have begun to diversify crop rotations for a variety of environmental and economic reasons. Ethiopian mustard (Brassica carinata A.) and camelina (Camelina sativa L.), two oil seed crops, can be successfully grown in the Northern Great Plains (NGP) and could be a suitable fallow replacement. Native bees have declined in abundance and richness primarily due to conversion of natural habitat to row crops and honey bees have become increasingly difficult to manage in recent years. Thus, it is important to determine how flower visiting insects utilize novel crops. We collected flower visiting insects via weekly sweep netting events during two growing seasons to determine abundance and richness of bees and other insect pollinators on B. carinata, C. sativa, and a ten species cover crop. Overall, numerous native bees and other flower visiting insects were collected off all three potential fallow replacements. These crops may provide important floral resources for bees and other pollinators and could be used to improve pollinator resources within cropping systems of the NGP.