Pollen associated with a Texas population of blow flies-(Diptera: Calliphoridae) highlights underappreciated aspects of their biology

Over 80% of agricultural crops rely on insect pollination. Thus, pollinator biodiversity is critical for augmented plant yield and quality. Blow flies (Diptera: Calliphoridae) are acknowledged pollinators of several crops. However, there are many open questions regarding their importance in pollination ecology. For instance, there has not been a comprehensive assessment of pollen use by blow flies, and thus, it is unknown whether individuals visit few or many plant types per trip. At least one blow fly species (Lucilia sericata) can digest pollen and use the protein therein as an oogenic resource. However, it is unknown whether this is a commonly used strategy for protein acquisition, given that they are more commonly associated with faeces, carrion and myiasis. We surveyed the pollen found in blow fly guts to determine whether blow flies (a) consume pollen, and if so, which types of pollen; (b) exhibit species-specific pollen use and (c) demonstrate sex-specific pollen use. We collected blow flies from natural habitats around Central Texas from 2016 to 2019 and dissected their guts to look for the presence of pollen. We found widespread use of pollen from a variety of plants by six blow fly species and discovered a bias in the amount of pollen collected by female blow flies compared with males in some, but not all fly species. Pollen represents a relatively underappreciated aspect of blow fly biology, with the potential for several underappreciated ecological impacts ranging from disease ecology to plant diversity.