Fruit Fly Culture Lid Modification

[MikeM670]

Fruit Fly Culture Lid Modification

By Michael W. McCormick

There are two problems I have encountered in using the large 32 oz plastic containers and the snap on lids. The first is keeping the fruit flies out from under the rim of the lid where I squish them when attempting to put the top back on. The other one is how to keep fruit flies from getting away when trying to either feed them directly to the vivarium or prepare them for dusting. The solution I have come up with is to modify the lid to accept the cut off pour spout of either a plastic soda bottle or water bottle.

Above image shows the completed containers. The left container with the yellow spout is a pop bottle and the right container with the white spout is a plastic water bottle. I found each type of spout has its advantages and disadvantages. The pop bottle is made of thicker more flexible and sturdier plastic but the top is a bit harder to spin off so you would not want to over tighten it. The water bottle plastic is more brittle and thinner however the top seems to spin off easier.

The process is simple and can be accomplished with most tools and items found at home. Here is the list of material and tools you will need.

• 32oz plastic culture cup
• ventalated lid for culture cup
• plastic soda or water bottle
• hot glue gun
• #11 X-ACTO knife
• small sharp scisors
• thin point marker
• 3oz plastic cup

The first step is to mark out the cut location on the plastic bottle. I do this by placing the plastic cup over the spout and using a black marker trace a circle around the bottle using the small cup as a guide. The left image below shows how I centered the plastic cup on the bottle and mark the circle with the marker. The right image below shows the bottle ready to be cut.





I first cut the spout out below the marker line to remove it from the bottle and make it easier to trim to the line.





The next step is to take the cut out spout and use it as a template to mark the circle on the vented lid where we wish to remove plastic.







It is very important when cutting out the opening in the lid top that you cut inside the line to allow room for the hot glue. In the image below I have applied a generous amount of hot glue around the opening in the lid. I then press the spout onto the lid so the glue oozes out the outside edge.





If there is not enough hot glue oozing out around the edge I simply reapply a bead around the outside edge to provide a better seal. Not so much to keep the fruit flies from escaping but to provide additional strength to the top when the lid is removed to clean out the cup and ready it for the next use. With proper care when removing the lid I believe the lid can be used for a very long time.
You will not be able to stack the cups on top of each other to save space but I believe the convenience of the pour spout outweighs the need for additional storage space.