D3071: Seasonal abundance of a stem-boring pest of quinoa, Amauromyza karli Hendel (Diptera: Agromyzidae) and its implication for pest management

Quinoa, Chenopodium quinoa Willd has been cultivated in South America for over 5000 years and is rapidly gaining popularity in new growing regions owing to its high nutritional value and low water requirements. However, quinoa’s production in new areas such as Colorado has been recently plagued with outbreaks of a stem-boring fly, Amauromyza karli Hendel (Diptera: Agromyzidae). Larvae of the fly feed inside the stem leading to pith destruction, which can result in plant death or severe yield loss. In 2021 and 2022 all acres of quinoa in Colorado were infested with A. karli. There is limited information about this pest, and the goal of this work was to establish the patterns of abundance of A. karli in the field. We monitored A. karli populations over the crop growth period in San Luis Valley and found that the fly abundance differed significantly over the study period with the highest fly activity reported in mid to late July. These findings have greater implications for developing pest management strategies. By predicting the highest infestation periods, we can modify the planting dates and timing of management methods accordingly to decrease the pest levels. By considering the temporal dynamics of pest populations, more targeted and sustainable approaches to pest control can be developed.