Are tiny flies pestering you and your Dubia roaches? Want to know how to get rid of them? If so, great, because I am going to show you a pesticide-free method learned from many years working as a bug farmer and as an exterminator.
More often than not the small flies interested in our Dubia roach bins are called Phorid flies. They are easily distinguished from fruit flies because they have dark black eyes while fruit flies have red eyes. These are a small humped backed fly that seem to prefer running around on surfaces rather than flying (all of the time). The reason why this is important is because Phorid flies are easier to catch with a surface type trap, instead of the ones often used for controlling fruit flies. Phorid flies are also attracted to dead and decaying material such as dead Dubia roaches and wet frass. This small fly also grows best in the same environment as our Dubia Roaches but with some slight tweaking of your temps and humidity it is possible to reduce the population.
Controlling Phorid flies is pretty easy, and simply breaks down into a few steps.
Step 1.
First, let's remove whatever is attracting, sustaining, and feeding the flies. If there are dead Dubia roaches on the floor of the bin, do your best to remove them, same with any food waste. You can use a vacuum cleaner to make quick work of many bins. Also, is there moisture building up along the walls, or a leaky waterer that could be providing moisture to the frass? Wet frass will serve as a substrate for fly larva to eat and grow.
Step 2.
Sometimes flies are just a symptom of incorrect humidity or ventilation. Unnecessary moisture and humidity provide the perfect environment for Phorid flies. The humidity inside of your Dubia Roach enclosure does not need to exceed 50% for the insects to do well. You can reduce humidity to 35% to help control Phorid flies without affecting your Dubia roaches but going much lower may be problematic to the long-term success of your colony.
Step 3.
To reduce numbers and control the flies you want to build a simple trap. The best traps for controlling Phorid flies are glue boards with a cap of vinegar in the middle. Always be careful to not let any pets get caught in the glue boards. If a pet is caught in a glue trap use any cooking or vegetable oil to neutralize the sticky glue. The glue board works so well because it takes advantage of the Phorid flies' preference to run around and catches them in the act. Fruit fly traps do not work as well for Phorid flies as they miss the majority of the flies that do not leave the ground. This trap works well on top of the lid for your Dubia roach bin where flies enter/exit the container.
Step 4.
It is important to maintain a clean environment by checking the frass for dead bodies once or twice a week. You can also replace the glue boards/vinegar traps regularly as well. Doing these steps periodically will help reduce or eliminate Phorid flies from your Dubia roach colony.
Flies are gross and follow the steps above to reduce or remove them completely from your colony. The better you do at following the steps above the better results you will have removing flies from your colony. Just know that skipping steps or relying on drying out your colony too much will reduce the lifespan of your Dubia roach colony and will not remove the flies long term.