When you perform fly behavior experiments, you don’t want to use recently anesthetized flies since the common anesthesia that we use (typically CO2 or cold) can affect behavior because they are stress signals. So how do you gently move your flies, without anesthesia? You use a fly aspirator.
A fly aspirator (aka pooter) is a simple device to draw flies into a collection chamber by applying suction force through a tubing system. It is non-invasive and allows us to collect and move flies without harming them. There are probably as many variants on fly aspirators as there are fly behavior labs. There are commercial pooters available, like at bugdorm, but I’ve only ever used ones that we build ourselves in the lab. Here is a simple way to build one that we use in the lab and for teaching fly behavior in courses.
Materials:
Rubber tubing
A small piece of mesh
A 1000uL pipette tip
1 200ul pipette tip
Something to cut the pipette tips and tubing (I like to use razor blades because sometimes cutting the tips with scissors causes little cracks in them)
Assembly Instructions:
Cut the tubing long enough you can hang it around your neck - like a stethoscope. That way you can just carry the aspirator easily without having to remember to pick it up when you move from one bench to another when you are performing experiments.
Place the 200uL pipette tip near the mouth end of the aspirator (you may want to cut the small tip of the pipette tip so you have more suction)
Cut the tip of the 1000uL pipette tip just large enough to fit a fly
Place the mesh near the fly end of the aspirator
Push the large end of the 1000uL pipette over the mesh and onto the tubing.
Optional: If you need an aspirator that picks up lots of flies, instead of a 1000uL pipette tip, you may want to use a disposable 5mL or 10mL serological pipette that you cut to your desired size.
Some tricks to easy and successful fly aspiration:
Use a sponge or memory foam plug on the fly vials that you want to collect flies from. It’s difficult to squeeze your aspirator tip into one of the hard flugs and sometimes it results in a little tunnel in the flug that the flies can escape from.
Collect more than one fly at a time. For example, If you need 10 flies in your behavior chamber, collect 10 flies in your aspirator and then blow them all at once into the behavior chamber.
Blow gently into the behavior chamber. If you blow too hard the flies get banged around.
If you are worried about variation in your breath affecting behavior, always chew the same type of gum right before you start the experiment.