PHYTOSANITARY ANALYSIS OF FRAXINUS UHDEI AND ECONOMIC IMPACT OF ITS BARK BEETLE IN THE SECOND LARGEST PARK OF MEXICO CITY

The San Juan de Aragón Forest (SJAF) is the second-largest park in Mexico City; its importance includes environmental, aesthetic, economic, and recreational aspects. Among the challenges being faced is the bark beetle Hylesinus aztecus (Wood), a pest specializing in attacking old ash trees Fraxinus uhdei (Wenz.) Lingelsh. To contribute to the understanding and management of this beetle, between June 2022 and July of 2023; we carried out a phytosanitary evaluation of the ash trees utilizing six parameters describing the crowns, as well as dasymetric data (July 2023). Our evaluation also included direct surveys and baited traps of 70% ethanol, distributed in strategic zones of the park, over eight months (October 2022 to June 2023). In addition, other information was gathered to obtain an estimate of the economic impact of H. aztecus in the SJAF. In comparison with data from a previous study from 2013, the ash trees grew 10.62 cm in diameter but lost 12% of their foliage. The insect infestation was at an advanced stage, as the emergence holes were less than 1 meter high. In addition, this was also the second documented attack on young ash trees by H. aztecus in North America, a behavior that has not been described in classical literature. The management of H. aztecus in the SJAF cost was estimated near to $300,000 USD in 2022 and includes chemical treatment of 50% of the ash trees, tree trimming, cutting down of trees when appropriate, reforestation, and management of the soil in affected sites. Considering this, in conjunction with the inefficient approach of trapping, it is suggested that other options for improving the collection of H. aztecus be explored. Key Words: Oleaceae, Scolytinae, Urban entomology management