What can science do to affect the behaviour of true fruit flies, Tephritidae, one of the top alien invasive group of species in the world? True fruit flies, some of which we rear, collectively ‘prey’ on several hundreds of different species of fruit plants for oviposition, causing fruits and vegetables to become unmarketable as the hungry larvae destroy the fruit inside out, leading to fermentation and abortion of the fruit. Host plants include mango, guava, banana, orange or many more of great horticultural importance and the impact for small growers can be devastating with extreme to total crop losses. Many of the species are currently spreading at an alarming speed. As an example, Bactrocera dorsalis have invaded almost the entire sub-saharan Africa in less than twenty years.
In our group we are investigating the chemical ecology of true fruit flies, to understand how they orient in a complex environment of volatiles. Our ultimate goal is to accelerate the development of novel attractants to be used in the field. To our disposal we have an “in-house” designed 6-choice essay, that is also currently running in Ethiopia and Bolivia. We also have the ability to capture volatiles using SPME (Solid-phase microextraction) and analysing them using GC-MS (Gas chromatography–mass spectrometry) and GC-EAD (coupled gas chromatography – electroantennographic detection). Although we have analyzed many fruit extracts and the fruit fly responses to these, we, and in fact the scientific community in general, has a poor understanding of WHAT and WHEN various sources (food, fruit, other sex) are attractive to flies. This is a really underexplored question, but very important to resolve: flies reach sexual maturity only after some 8 days, before which they need to find proteinaceous sources for maturation, and after which they need to find mates and oviposition sites. Following an initial oviposition bout (or mating) they probably will re-engage in finding food, but we have a poor understanding of the volatiles that are key in the above shifts.
With your help we are keen to decipher how volatiles from fruits and microorganisms in a complex environment can be used to attract/repel fruit flies throughout their lives as flying insects.
We are always interested in finding highly motivated master students, if you are interested please email (sebastian.larsson.herrera[:at:]slu.se).