Assessing field-based emergence estimates of Dasineura oxycoccana L. from soil and blueberry buds

Florida blueberries are valued at $62 million USD. With almost a million metric tons expected to be produced by 2021, the blueberry industry is under serious threats from the blueberry gall midge (BGM), Dasineura oxycoccana Johnson (Diptera: Cecidomyiidae). In 2018 and 2019, the BGM was the most destructive pest of blueberries in Florida, with approximately 58% of farms reporting heavy infestations and a significant decrease in yield. This study provided field-based estimates on emergence times of different life stages of BGM. The experiment was conducted in a highly infested conventional Southern highbush blueberry field in central Florida during peak infestation. From 6 AM – 6 PM, bucket emergence traps were interchanged every three hours at random locations within the experimental field and replicated on four separate days. Upon each deployment, the plexiglass on bucket traps was sprayed on both sides to investigate densities of emerging adults from the soil below and the number of larvae falling from above. Results indicated that 46% of larvae emerged from 6 – 9 AM when temperatures averaged 19 °C. Thirty-six percent of males emerged from 9 AM – 12 PM, and 37% of females emerged from 12 – 3 PM, at average temperatures of 24 °C and 29 °C, respectively. It is critical for growers to know the preferred time of day in which to apply the proper insecticide to target each life stage of this pest. This crucial step mitigates the establishment and spread of BGM in Florida's blueberry plantings.