Nesting Biology and Ecology of a Resin Bee, (Megachilidae: Hymenoptera).

We report the nesting biology and ecology of Smith, 1853 for the first time in Pakistan. Wooden and bamboo trap nests were deployed at three different locations in Bahawalpur district, Pakistan, from January 2020 to May 2021. A total of 242 nests of were occupied in all three locations with the maximum abundance in the Cholistan Institute of Desert Studies. remained active from March to September (the spring and summer seasons). In a nest, females made 7-8 brood cells each having a length of 1.2-2.3 cm. Plant resin was used to construct cells and mud or animal dung to plug the nest entrance. A vestibular cell was also made between the outermost brood cell and the nest entrance that ranged from 1.4 to 2.5 cm in length. No intercalary cells were observed in the nests. The males took 65.3 days to become adults, while the females took 74.78 days. The sex ratio was significantly biased toward females in all three locations. was the predominant pollen grain species found in the brood cells. were observed collecting resin from , , and . Three cleptoparasites of this species were also recorded: , sp., and sp. This study set up a background to encourage new studies on artificial nesting and provides tools for proper biodiversity management and conservation.