Doctor Scott Nacko


Graduated PhD 2023

Thesis Title

Pollination potential, thermal biology and genetic diversity of Australian stingless bees

Research Project

Pollination potential, genetic diversity and thermal limitations of two Australian stingless bee species in temperate cropping environments

Crop pollination is an important aspect in the production of food products. Although many animals contribute to pollination, honeybees (Apis mellifera) are used worldwide as crop pollinators, and are often heavily replied upon in agriculture systems. But the honeybee is facing many threats, such as the Varroa destructor mite and deformed wing virus, and is an exotic species in Australia. Thus, we must be prepared to identify native alternative pollinators, such as the stingless bees.

Like the honeybee, stingless bees are eusocial, and live in colonies which can contain 10,000 individuals depending on the species. In Australia there are 2 genera of stingless bees: Tetragonula with 6 known species and Austroplebia with 5 known species. The majority of these species occur in the tropical northern regions of the continent, however one (Tetragonula carbonaria) has a large distribution spanning from the coast in central Queensland south into temperate regions of New South Wales. In Australia there have been few studies regarding the importance of stingless bee pollination in crops, but they have already been shown to be effective pollinators of macadamia and celery.

My project aims to address the efficacy of two stingless bee species in pollinating temperate vegetable crops, specifically cucumber and watermelon. In addition, because T. carbonaria has such an extensive distribution, we aim to test the thermal limits of different populations, and whether there is population genetic structure within the species, shedding light on which populations might be more adept for use in particular agricultural systems. Lastly, with the keeping techniques of stingless bees still under development, we will examine queen turnover rates in managed colonies of T. carbonaria. Ultimately this research will provide information regarding the importance of stingless bees in pollinating cucurbit crops, and genetic/life history traits which may be crucial in the further development of beekeeping techniques.


Liu H, Hall MA, Brettell LE, Wang J, Halcroft M, Nacko S, Spooner-Hart R, Cook JM, Riegler M, Singh B, (2023) 'Microbial diversity in stingless bee gut is linked to host wing size and influenced by the environment', Journal of Invertebrate Pathology, vol.198, p 107909

Nacko S, Hall MA, Gloag R, Lynch KE, Spooner-Hart RN, Cook JM, Riegler M, (2023) 'Heat stress survival and thermal tolerance of Australian stingless bees', Journal of Thermal Biology, vol.117, art no.103671

Nacko S, Hall MA, Henderson G, (2022) 'Alternative Nesting Strategies of Polistine Wasps in a Subtropical Locale', Insects, vol.13, no.1, Article no.53

Nacko S, Hall M, Spooner-Hart R, Cook J, Bernauer O, Riegler M, (2022) 'Cucurbit crops in temperate Australia are visited more by native solitary bees than by stingless bees', Journal of Apicultural Research, vol.61, no.5, pp 675-687, Special Issue

Hall MA, Brettell LE, Liu H, Nacko S, Spooner-Hart R, Riegler M, Cook JM, (2021) 'Temporal changes in the microbiome of stingless bee foragers following colony relocation', FEMS Microbiology Ecology, vol.97, no.1, fiaa236

Nacko S, Hall M, Duncan M, Cook J, Riegler M, Spooner-Hart R, (2020) 'Scientific note on small hive beetle infestation of stingless bee (Tetragonula carbonaria) colony following a heat wave', Apidologie, vol.51, no.6, pp 1199-1201


Professor Markus Riegler, Professor James Cook, Dr Mark Hall, A/Professor Robert Spooner-Hart