Dalotia coriaria are a wonderful predatory beetle that can be used to help control aphids, fungus gnats, shore flies and thrips. Breeder boxes are a great way to maintain and grow populations of the beetle cheaply and easily. You will need:
- 1 roughly 12"x12" or 8"x8" container, we've seen people use Tupperware but we typically use Styrofoam boxes
- sharp knife
- tape measure
- bridal veil or other fine mesh material (optional)
- chick feed, koi feed, dried bloodworms or another high-chitin food source
- organic potting soil and/or compost rich medium
- Around 500 Dalotia
1) Cut two 2"x2" holes on each end of the box.
2) If you plan on establishing the breeder box before moving it near your pots or rows, use fine mesh and tape to block the holes. This step maintains adequate ventilation and prevents the Dalotia from escaping. If you plan to use them for control immediately, skip this step.
3) Fill the box to about 3" with organic potting soil and/or compost rich medium. For this one we used about 70% potting soil and 30% vermicompost. Afterwards, water to moisten soil mix.
4) A variety of foods work, but typically you want something high in protein and ideally high in chitin (the material in insect exoskeletons). Koi fish food, chick feed and blood worms are some examples. For this box, we used a mix of about 2 tbsp of chick feed and 1 tbsp of freeze dried blood worms. Grind up the food in a coffee grinder or mortar and pestle for best results. The mix should be sprinkled across the soil surface. Add a little more food weekly.
5) Release at least 500 Dalotia into the box and close the lid tightly! You can add some tape to hold it down.
6) The last step is to place the box in a nice humid, shaded area. If you plan to release them immediately, place the box underneath your greenhouse benches near the plants.
Soon, they will start breeding, the adult females laying eggs right into the soil. The juveniles will pupate in the soil system, and when they reach adulthood, emerge from the soil. When the Dalotia are feeling crowded, after a few weeks, they will emerge from the holes in the box, and take short - hopping flights up into the plant system, seeking thrips pupae in the soil, as well as fungus gnat and shore fly larvae, and other assorted prey in the canopy. They are vigorous searchers and will find their way around your growing system.
IMPORTANT!! No need to disturb the crusty surface of the soil in the box, even if a little “bread mold" forms on the surface. Do not allow the medium to be wet, just keep moderately moist. If a little algae forms, this is a good thing! Periodically check the vigor and activity of your Breeder Box, and refresh as needed