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Methods for interpreting  emergence trap specimen data for the study of ground nesting bees (Hymenoptera:  Anthophila)
  • Zachary M Portman,
  • Julia Brokaw,
  • Daniel P Cariveau
Zachary M Portman
University of Minnesota, Co-first and corresponding author. Contact: [email protected] and [email protected]

Corresponding Author:[email protected]

Author Profile
Julia Brokaw
University of Minnesota, Co-first and corresponding author. Contact: [email protected] and [email protected]
Daniel P Cariveau
University of Minnesota


Emergence traps have increasingly been used to study ground nesting bees. They offer an advantage over other methods, such as netting or passive traps, because they can directly measure ground nesting bees at a landscape scale. However, emergence trapping for ground nesting bees has limitations, including low catch rates and data that is difficult to interpret. For example, emergence traps catch a combination of actively nesting bees, newly emerging bees from nests provisioned the previous year, overwintering bees, and incidental bees, such as non-ground-nesting species or bees that were simply sleeping on vegetation. Further, a single emergence trap can capture many specimens from a single nest due to the presence of workers, newly emerging reproductives (gynes), or multiple siblings from a nest provisioned the previous year. Due to these factors, a thorough knowledge of the life history of bee species collected is necessary to accurately filter and interpret the data. Here, we provide methods to determine whether bee specimens caught from emergence traps came from nests. Using a combination of trap data, life-history characters, and estimates of bee age, we classify bees as newly emerging, active nests, or incidentally caught. This will allow researchers to reduce the risk of spurious inferences that may over- or under-estimate bee nesting. Many areas of future research remain, particularly studies on the efficacy of emergence traps for ground-nesting bee research as well as a glaring need to better document the life-history of many bee species.   Abstract content goes here