Can we collect flies in citrus fields?



Can we use the farmers’ insect traps, or is it possible that they have insecticides and this influences the results?

It is necessary to confirm with farmers in advance whether or not the traps have insecticides (or other variables that may affect the collection, such as foods that are preferred by some species). If they don’t have any of these variables, then you can collect them, but it will be necessary to point out on the post-collection form that you used that collection method. If there were variables present that could confuse the results, such as those mentioned above, it would be ideal NOT to use the traps for the collection. However, if there’s no other option, they could still be used (Always make note on the post-collection form that the flies were collected from farmers’ insect traps).


Can flies be left with food for a while and then sorted?

Yes, as long as the food is the same as from the field where the collection took place. This way, the microbiota composition won’t be modified. To do this, it will be necessary to take a piece of fruit from the field—avoiding rotted fruits—and put it in the field-collection via. However, we recommend doing the flies’ classification on the same day of the collection.


Can the flies be harvested in November (when the fruit is picked in some places)?

If on the day of fly fruit collection (at any time) there are flies in the crop fields, they can be collected on that date. Nevertheless, it is advisable to collect flies as close as possible to the summer, in order to homogenize with respect to other schools’ collections.


Is there a problem if I can only collect once a year?

It would be great if you could  do two collections during the year. Once before, and once after summer. However, if this is not possible, it is ok to collect only once a year.


How do you collect in places where agriculture is based on smallholding farms in which new crops are planted very quickly?

If the planting of new crops occurs very fast, then the best thing to do is to agree with the farmer in advance what day the fruits will be harvested, and then collect the flies on the same day.


How can aspirators be fabricated by hand?

More information can be found in the Sampling & Classification (How can aspirators be fabricated by hand) in the Resources Section.


What happens if we are not able to differentiate between the different types of Drosophila?

It is important to become familiar with the differentiation process in order to be able to send the separate species for sequencing. If you have trouble differentiating them, you can send the collected samples without sorting, saying that they have not been previously classified.


What happens if we cannot find Drosophila melanogaster?

The ideal is to find flies of all the species analysed (mainly D. melanogaster, D. simulans, D. suzukii, other Drosophila species can be D. subobscura), however, the distribution of the species can vary between locations and from one year to another. For that reason, it is possible that you may not find all types of flies. If you find enough flies of other species, you can send them even if there are no Drosophila melanogaster.