Culturing Feeder Insects

Culturing Fruit Flies:

D. Melanogaster

1) Place 1/4th cup FNT's Optimized Culture Media into a 32 oz Insect Culture Container (alternatively, flies can be cultured in mason jars using a coffee filter as the lid).

2) Add 1 tbs apple cider vinegar (an optional mold preventative) plus 1/3rd cup filtered, room temperature water.

3) Once mixture is firm, sprinkle several 10-20 grains of active dry yeast over the media. The yeast will help process the media and will out-compete molds growing on the surface.

4) Add 20-30 flies. Using the first flies to hatch from a culture to seed a new culture helps maintain the colony by selecting for the healthiest flies.

• Depending on temperature and moisture content, new flies will hatch in approx 2-3wks.

• Culture media should remain moist but not runny. You may need to add more or less water to the cultures based on humidity levels (more water can always be added later if cultures begin to dry).

• Promptly discard any moldy cultures or any cultures contaminated by mites or flying flies.

• Start a new batch of cultures at least once a week to ensure continued production. One 32 oz culture/wk is generally sufficient for 2 adult frogs.

• Prior to feeding, dump flies into a secondary container and dust with 1:1 calcium/D3:vitamin supplements. We recommend Repashy Calcium PlusDendrocare,  or a 1:1 mix of Repashy Supercal and Supervite. Please adhere to supplement expiration dates as potency rapidly declines over time.

D. Hydei

• Use directions for D. Melanogaster above, EXCEPT do NOT seed cultures with the first flies to hatch. Rather, wait 10-14 days after the fist flies hatch before using the culture to seed a new one. Male Hydei take longer to hatch than the females.

Preventing Mites

Mites are everywhere. They are going to get into your frog room and tanks. So, how can you keep them out of your insect cultures? Here are a few tips:

1) Always check cultures for mites, and discard any contaminated cultures immediately.

2) Microwave culture containers and media (before adding water) to kill any mites.

3) Always use the newest (and preferably never opened) producing cultures to seed new ones. This is especially effective with melanogaster as the life cycle of melanos is shorter than the mites. Thus, seeding a new culture as soon as flies emerge does not give any contaminating mites enough time to reproduce.

4) Keep cultures inside a secondary container that is lined with mite paper. To make your own mite paper, spray paper towels with miticide and let dry. I use pyrethrin/piperanyl butoxide based mite and lice spray. There are also “all natural” formulations available, but I have not tested their effectiveness. Keep in mind that “natural” or “organic” formulations are not necessarily safer than the synthetic insecticides. Case in point: batrachotoxin (dart frog toxin) is 100% natural/organic.

5) Keep older cultures in separate containers than new ones.


Culturing Springtails (Collembola)

There are many methods for culturing springtails. Common substrates range from charcoal, peat, wood chips, coconut bark, etc. Commonly used foods include flake food, mushrooms and yeast. After trying numerous variations and combinations of these substrates/foods, we find that the following to be easy, cheap, and to work equivalently or better than the other approaches.

1) Soak hardwood wood chips in dechlorinated water for a minute or two. Decant water and blot wood chips with a paper towel to remove excess water.

2) Fill a >16 oz Tupperware container ~1/2 full with the moistened wood chips.

3) Microwave for ~1 min (until thoroughly steaming) to sterilize culture.

4) Let culture cool to room temperature.

5) Add 30-50 springtails.

6) Feed with a pinch of springtail food and/or instant yeast 1-2x per week. Alternatively, the springtails thrive on reconstituted dried mushrooms. We do NOT recommend using fresh mushrooms as this is likely to introduce mites into the culture eventually.

Culturing Bean Beetles/Weevils (Callosobruchus maculatus) 

Bean beetles are extremely easy to culture. Their larger size and prolific production make them a great alternative to D. Hydei.

1) Place ~2 inches black eyed beans in the bottom of a 32 oz Insect Culture Container.

2) Add ~30 beetles.

• No water or food (other than the beans) is needed!!

• Beetles will lay eggs on beans. Once eggs hatch, larva will bore through beans and emerge as adults in ~ 2 months. Adults do not eat.

• A simple way to dispense beetles for feeding frogs: Remove the paper mesh from the lid of a 32 oz Insect Culture Container. Cover the holes using ¼ inch wire mesh. Put this lid on a culture from which you want to feed, and simply shake the beetles through the lid. The mesh will trap the beans in the container.