Bees found in watermelon in the Lower Rio Grande Valley of Texas

Interest in native pollinators for use in agricultural systems has increased in recent years due to declines in honey bee (Apis mellifera L.) populations. This interest has been especially great in crops relying heavily on insect pollinators, such as watermelon. Using a combination of pan traps and visual observations, we surveyed three watermelon fields in the Lower Rio Grande Valley to determine what bees inhabit watermelon fields in this region. No managed A. mellifera hives were in any of our fields; however, two of the fields contained introduced managed colonies of the common eastern bumble bee, Bombus impatiens (Cresson). Survey results indicate <10 species groups were collected/observed from individual fields, as well as from all three fields combined. Apis mellifera comprised approximately 50% of all bees collected/observed in each of two fields. In the third field, A. mellifera and Agapostemon sp. were equally abundant, and together comprised about 70% of all bees collected/observed. Despite two fields having several B. impatiens colonies each, this species only comprised 3% of the total bees collected/observed in each of these fields. As B. impatiens is not native to this region, it was not surprising that none were collected/observed in the field without introduced colonies.