Microbiota characterisation in hoverflies under HOVERpollination project.
Hoverflies (Diptera: Syrphidae), also called flower flies or syrphid flies, are special allies for many crops. Adults feed mainly on nectar and pollen, becoming of interest for certain crops requiring pollinators (ie. cherry tomatoes, watermelon, …), due to the decay of native bees and bumblebees populations or when under certain circumstances these two groups do not perform well. Hoverflies adults are responsible for the pollination of more than 500 crops, becoming the second most important pollinator species after bees (Doyle et al., 2020). Depending on the syrphid species, larva can be insectivore (preying on aphids, thrips and other plant-sucking insects) or saprotrophs (feeding on decaying plant and animal). Insectivore species are also of interest for plant protection, as they could reduce insect pest populations, reducing the need of chemical treatments to protect crops. Thus, hoverflies provide a number of ecosystem functions (crop protection, recycling organic matter, long-distance pollen transfer) in top of pollination services, not seen in bees or bumblebees (Doyle et al., 2020; Li et al., 2023).
Insect species, like any other organism, harbour a plethora of microorganisms (ones beneficial, other pathogenic, and many more just commensalists), that conform the microbiota. Like in humans, insect microbiota can be modulated by feeding with pro- and pre- biotics. But, as difference with humans, there is a part of the insect microbiota that is maternally inherited, and that is required for insect development and biology, they are the symbionts. Within this bacterial group, we can found several species that affect the reproductive biology of the insect, like Wolbachia, Rickettsia, Cardinium or Serratia, among other bacteria, that are being developed into biotechnological tools for pest control (Zabalou et al., 2004; Bourtzis 2008; Gong et al., 2023). The understanding of microbiota-insect interactions is essential for both, insect production in bio factories and vector-borne diseases control (like malaria, West Nile fever, dengue, African sleeping sickness, river blindness, leishmaniasis … as examples of human diseases, or like HLB or Citrus greening, Pierce’s disease, citrus variegated chlorosis, citrus canker, tomato chlorosis, … as examples of plant diseases) (Eigenbrode et al., 2018).
Depending on the ecosystem function required in protected crops (greenhouse), either pest control or pollination services, the selection of the proper hoverfly species can become a challenge, specially under the actual climate change scenario. Within this project, we aim to determine microbiota composition over hoverfly development, by using 16S rDNA deep sequencing.
The student will be involved in insects dissection, bacterial DNA isolation, libraries construction and analysis, and in verifying by routine PCR the presence of several known bacterial species.