In the tropics, specialization of the interaction between plants and pollinators tends to decrease . In fact, wild bees can shift their floral resources, showing behavioral flexibility towards alternative floral resources. It leads to open niches, easily exploitable by other bees, such as introduced honeybees. However, on tropical islands, the floral resource diversity is much lower than ecologically similar continental regions, so the availability of resources might be lower for wild solitary bees whenever a superior pollinator enters the niche. Responses of wild bees to the introduction of honeybees on tropical islands vary. Although Puerto Rican honeybees are reported as gentle in terms of aggressiveness by showing less defensive behavior , no studies have been reporting on their direct effects on wild bees. Furthermore, because most of the honeybee’s hives in Puerto Rico are feral, it is difficult to track honeybee dispersion. Due to their highly efficient foraging behavior, they could compete with wild solitary bees for floral resources and nesting sites. From the microbiome perspective, a change in microbiome due to obligated niche shift could lead to dysbiosis, and thus a higher susceptibility to pathogen invasion, highlighting the necessity to conserve the eubiotic microbial community.