Symbiotic associations in flies
It is commonly thought of multicellular organisms as of biological units, or as populations composed of individuals. However, all bear associated bacterial communities that perform functions essential for their well-being – or in other terms functions that may impact upon their fitness. Insects are practical models to study such interactions as they are small, numerous and may sustain less complex bacterial communities than larger organisms. Certain insects, like tephritid fruit flies are important agricultural pests; others, like blood sucking flies are important animal parasites. Understanding their relationships with their bacterial communities may offer novel opportunities for controlling them and in turn, the damage they cause.
Our research on symbiont-fly interactions is based on a symbiotic association - with the Yuval lab of Entomology (http://departments.agri.huji.ac.il/entomology/boaz_yuval/index.html).
Community adaptation in Ceratitis capitata, the Mediterranean fruit fly
The Mediterranean fruit fly (the medfly) is a widely distributed, polyphagous fly. Its larva grows within many kinds of fruits, causing great losses. While the medfly’s gut bacterial community is large and diverse, it expresses conserved functions. Knowledge of community composition and functions plays an increasing role in the control strategy known as the Sterile Insect Technique (SIT). Yet, we barely understand if and how gut symbionts are selected, e.g. bacterial community adaptation to the fruit or other growth media, affecting larval development; the sources of diversity of the gut community, and transmission bottlenecks during development.
The unique association of Bactrocera olea, the olive fly with a gut symbiont
Bactrocera olea, the olive fly is a major pest of olives. It is one of a few insects able to overcome the chemical defences of green olives, with its larvae consuming the fruit and inflicting great damage to growers. The fly has a dominant symbiont, Candidatus Erwinia dacicola, a so-far uncultivated species. This system, in conjunction with the analysis of other local monophagous flies, and the possibility to manipulate colonization of the fly's gut let us ask fundamental questions about the evolution of monophagous pest flies, and about trade-offs between life stages. Furthermore, this knowledge can be applied to cultivate the olive fly's symbiont, and enable adaptation of the fly to mass-rearing for the SIT.
Microbe-host dynamics in Philornis downsi, a parasite of Darwin finches
Philornis downsi is an invasive blood-feeding avian parasite that has invaded the Galapagos archipelago, inflicting high mortality to the small birds inhabiting the islands, prominently to Darwin finches. As part of a large international team aiming at controlling the parasite, we study which microbes are associated with the various life stages of the flies, the effect of bird host species, geography, and growth under lab conditions on the fly's gut community composition. We aim at finding a way to produce and keep fly colonies in the lab to help establish SIT; in addition using trapping experiments, we study whether gut community members affect the fly's behaviour.
