In this article the ecology of springtails will be briefly discussed, as well as their uses in Dart Frog Vivariums. Different methods of culturing springtails, and each of their benefits and drawbacks are also covered.
Temperate White Springtails (Folsomia candida) are small terrestrial invertebrates (up to about 0.1”) that can be found in soil environments worldwide. There are also Tropical Springtails, as well as springtails of different colors. However the durability and high fecundity of Temperate White Springtails has resulted in them being by far the most common one used in vivarium keeping.
The name “Springtail” comes from the predator avoidance strategy they employ using a tail-like appendage called the furcula. Releasing the furcula, in an action similar to a mouse trap being triggered, launches the springtail aimlessly away from the threat.
Springtails serve multiple roles in vivarium keeping as well as dart frog breeding. Springtails act as part of the “Clean-Up Crew” (CUC) in a bioactive vivarium. Along with other invertebrates, such as isopods, springtails help create a more fully functional enclosed ecosystem. Springtails will help breakdown waste (dead/decaying vegetation, frog waste, dead flies, etc.), which results in more complete nutrient cycles such as that of Carbon and Nitrogen.
In addition to joining other microfauna in making a vivarium “bioactive” springtails are also crucial for helping to feed Dart Frogs, specifically newly metamorphed froglets of smaller Dart Frogs such as those in the genuses of Ranitomeya and Oophaga. When these Dart Frogs first come onto land after metamorphosis they are typically too small to be able to consume even stunted fruit flies. Springtails provide an easily cultured food source of an appropriate size for these frogs until they grow large enough to be able to be weaned onto fruit flies. For this reason NCDartFrogs has literally hundreds of springtail cultures growing at any point in time.
The ecology of springtails is fascinating due to the fact that they are parthenogenetic. This means that all springtails are female, and reproduce asexually via a process called parthenogenesis. In parthenogenesis an embryo develops from an unfertilized egg. Springtail eggs take around a week to hatch. Freshly hatched springtails are incredibly small, whose appearance to the naked eye resembles a light dusting of powder. Springtails grow and molt over the course of several weeks until they reach maturity. Once around 3 weeks of age they begin laying eggs, which may number up to a thousand during their 6-9 month lifetime.
Springtails can be cultured in a number of ways, using different methods and materials. Starter or “Seed” cultures of springtails are typically a small 8-12oz deli-cup, whereas “Master” cultures can be housed in larger shoebox sized containers. Ventilation of some sort is required, although considerations must be made to make sure the springtails stay in and any potential predators stay out. For these reasons many keepers provide only manual ventilation to cultures, by opening the lid once a week or so to feed and water them. Although F. candida can survive in higher carbon dioxide concentrations than many organisms (due to them having evolved living in a soil environment, where CO2 concentrations increase with depth) too high of CO2 levels for too long can result in a culture “gassing” itself and the culture crashing. When this happens all the springtails are still upon opening of the culture. In some instances it is not too late, and the springtails will revive themselves in 10-20 minutes after the culture is opened and fresh air allowed inside. However sometimes it is too late and a culture crash will be a permanent end to the colony. For this reason it is prudent to not rely on a single culture for your springtail needs, especially when young froglets are relying on springtails as their sole source of nutrition.
In most instances the increase in CO2 in a culture is not due simply to the respiration of the springtails, but rather to the fermentation and decay of the food source provided to the springtails. For this reason it is best to only add very small amounts of food to a springtail culture at a time. A variety of different foods can be used to culture springtails, with some of the most popular being baker’s yeast, fresh or dried mushrooms, and fish flake food, among other things. Grain based foods are best avoided to help deter grain mites from infesting the culture. The wide variety of suitable foods used to culture springtails is due to the fact that the springtails are not consuming the food itself, but rather the fungal hyphae of the mold that begins growing on and breaking down the food.
Temperate White Springtails require high humidity, and how this is provided depends on what substrate they are being kept. Charcoal and Calcium Clay are two of the most common substrates for keeping springtails, but other substrates such as peat or even agar can also be used.
Charcoal cultures are easy to make, typically using Horticultural Charcoal, although lump charcoal such as used for grilling is also an option. A container is filled with a few inches of charcoal, and then about an inch of water is added to the container. The water on the bottom ensures high humidity is maintained. To feed the springtails to the frogs a chunk of charcoal can be removed and added to the vivarium or grow out container. Alternatively the springtails can be harvested by adding water to the container. Due to the fact that the springtails will not submerge (they float) the rising water level will drive the springtails up to the top of the culture. With the population of springtails at the top of the culture a straw can be used to blow the springtails out of the culture and into a collection container (or directly into the vivarium). A benefit of charcoal cultures that takes advantage on the fact that springtails float is that the cultures can be flooded to maintain their integrity by eliminating any pests. Mites can sometimes become a problem in springtail cultures. When they establish themselves and their population grows they can result in diminished springtail production, either by competition or direct predation. However unlike springtails, mites tend not to float. A charcoal culture that has been infiltrated by mites can be flooded, increasing the water level above the top of the charcoal. The springtails will float on the surface of the water, while the mites hanging onto the submerged charcoal will drown. After this process is completed (overnight will do) the water level can be drawn back down with a turkey baster or pipette, allowing the springtails to once again achieve dominance. One drawback to charcoal springtail cultures is they do not ship well. During transport the charcoal will shift and grind, usually resulting in the death of nearly all springtails by the time they arrival at their destination. While this is a major setback to the culture’s population, not all is lost necessarily. Often times springtail eggs can survive the journey, an if left to recover for a week or so (instead of disposing of the apparently dead culture) baby springtails will hatch and begin to re-establish themselves.
The preferred method of culturing Temperate White Springtails at NCDartFrogs is with Calcium Clay Cultures. Calcium Clay cultures are made using a clay base, sometimes a mix of different clays depending on the recipe. Red Earth Clay and Calcium Bentonite are two commonly used main ingredients. Different minor ingredients such as powdered calcium carbonate and peat are often included to increase the benefits to the frogs when the springtails are consumed, as well as extend the life of the culture. Clay springtail cultures are made by mixing the dry clay powder with water to a thick consistency, and then spreading the clay around the bottom and the sides of the culture container. Texture such as craters and trenches can be imparted into the clay to increase the usable surface area of the clay for the springtails. Clay springtail cultures have several benefits. One of the major benefits is the ease of harvesting springtails. The clay springtail culture can simply be tilted over the feeding area or collection container and tapped to knock the springtails out. The springtails fall out, and the clay stays stuck to the container, quick and easy. The physical characteristics of clay also make shipping clay springtail cultures easy without harm coming to the springtails. Additionally springtails housed on clay may deliver some material benefits to the frogs that consume them by ingesting calcium and other minerals from the clay that is transferred on and in the springtails themselves. One drawback to clay cultures is they cannot be flooded to exterminate mites, but in my personal experience, as well as what I have heard from others, clay cultures seem to be less susceptible to mite infestations.
Springtails can be raised on other media, such as peat or other substrates. Such methods can produce booming springtail cultures just like charcoal or clay. Their drawback is that they can prove difficult to cleanly harvest the springtails from, as in separating the springtails from the media. For this reason they are best used in situations where the culture is seeded and grown until at time of harvest the entire culture, media and all, is added to the vivarium. This is best suited for situations such as when a new vivarium needs to be populated with springtails, and less ideal for feeding froglets when regular repeated harvests of springtails is needed.
That concludes this article on springtails! Feel free to order some and give them a try, your frogs will thank you!