Page 1 of 4 | © 2005-2010 text and photos by Michael Jacobi
The following is a reprint of the original article from ARACHNOCULTURE 1(2), but it has been slightly revised and expanded for this E-Zine version. For example, the brief comments on the cereal container housing for arboreals did not appear in the print version.
Above the ground we live upon exists a whole different world. While most birds, many insects and one mammal are capable of flight, the majority of the creatures that dwell above land inhabit vegetation, from tall grasses and short bushes to the canopy of the highest trees.
The majority of theraphosid spiders, or tarantulas, live in or on the same ground where humans tread. Most dig burrows into the earth where they are protected from predators and live in a micro-environment often cooler and more humid than conditions at ground level. These species are called obligate burrowers. Other terrestrial tarantulas are more opportunistic and find shelter in burrows or scrapes created by other animals, natural crevices in the earth, or beneath leaf litter, fallen branches and other ground cover. Still other tarantulas have adapted to a lifestyle above the ground. These arboreal, or tree-dwelling, species have a lighter build with thinner bodies and longer legs with increased tarsal scopulation. That is, their legs are flatter and have thick setae ("hair") on the edges of their metatarsi and tarsi, the last two segments of their legs. This increased surface area at the ends of their legs allows them to effortlessly climb any surface, while their light build gives them increased agility and protects them from falls.
Arboreal tarantulas also differ in habits. Some live in low vegetation such as high grasses, bushes and palm fronds [e.g., Heteroscodra]. Others live in the trees themselves, seeking shelter among the leaves or epiphytic plants like bromeliads [e.g., Avicularia], or live in tree hollows or holes created by birds or insects [e.g., Poecilotheria]. Due to habitat destruction many Poecilotheria, the ornamental tarantulas or tiger spiders, are often found living in dead trees.
The specialization of the arboreal tarantulas requires that their captive husbandry be modified from that of obligate burrowing, opportunistic burrowing or terrestrial species. Their housing should be vertically-oriented – tall instead of wide – with retreats that approximate those of their natural habitat. Their habits and reduced tendency to dig or otherwise rearrange their enclosure makes them ideal tarantulas for beautiful naturalistic vivaria with live plants. This article details methods for creating a captive environment appropriate for the care and breeding of arboreal theraphosid spiders.
I raise early instar arboreal theraphosids in 20 or 50 dram clear vials, later moving young of 1.5 in [38 mm] legspan to 32 oz. [1 liter] clear Solo® deli cups with insect cup style lids (see: Superior Enterprise). The approximate dimensions of the containers are: 20 dram – 1.5 in [38 mm] diameter x 2.7 in [68 mm] high; 50 dram – 1.9 in [48 mm] x 4.25 in [108 mm]; 32 oz. [1 l] cup – 4.5 in [114 mm] x 5.75 in [146 mm].
Elsewhere in this article I write of the use of beneficial organisms living in the substrate, but in the very small confined space of the rearing container I prefer more sterile conditions and use a slightly damp mixture of coconut coir [e.g., T-Rex® Forest Bed™, Zoo Med® Eco Earth™] and horticultural vermiculite [3 parts to 1]. Many young arboreal tarantulas will burrow or create a silken tube that continues below the surface. This mix makes it easy for them to create these retreats. I add substrate to a depth of about 1/4 the container height and tamp it down firmly. A piece of cork bark is situated vertically in the cage and a small leaf or two of silk plant added. I do not use water dishes in these containers, but rather mist a spot away from the spider so that it may drink from the droplets [see discussion of feeding and watering below].
Clear plastic gallon (and half-gallon) jars are excellent low-cost containers for housing juvenile arboreal tarantulas and even adults of smaller species. For a few dollars and twenty minutes time, they offer a space-saving solution to rearing a large number of arboreal tarantulas 2-4 inches in legspan.
First I drill several ventilation holes in the lid and use a soldering iron to put several holes about 2 in [5 cm] above the jar bottom and another series about 3/4 the jar height up from the bottom on opposite sides of the container. If you have problems with winged spest such as fruit or phorid flies affix microscreen (available from biological supply house across the inside each group of air holes. Alternatively, panty hosy or similar fabric can be used. Insect screening is only effective against larger pests; microscreen can be obtained from biological supply. As an alternative, panty hose or similar fabric can be used.
I then add enough moderately moistened substrate to come up to about a half inch below the lower ventilation holes. I personally use garden soil (plain old dirt) or a 3:1 mix of coconut coir and coarse horticultural vermiculite, but top soil, untreated potting soil, sphagnum peat moss and vermiculite alone can also be used. Generally, I will add isopods, wood lice or other "ground cleaners" to the subtrate. They will help with prey remnants, fungi, mold, etc. Some dry oak leaves and live moss can be added for both aesthetics and to contribute to the "living soil".
I then use a glue gun to affix a 2 oz [60 ml] condiment cup [e.g., Solo® or Dixie®] about 2/3 the jar height from the bottom, just below the upper ventilation holes. Two cups are needed - one will be glued to the side and become the holder, the other will be the actual removable water dish. After sufficient time has passed to allow the glue to set, I add the second water dish and put a silk plant leaf or flat rock inside to prevent prey from drowning. Then I add the finishing touches — the retreats for the spiders. These are made from bamboo, cork bark slabs or tubes and silk plants. The ratio of one to the other depends on the type of arboreal spider housed. For Avicularia I use plenty of silk plant and less wood; for Poecilotheria I primarily use bamboo and cork bark slabs or tubes and just use a touch of silk plant for decoration. A hollow bamboo piece with a round or oval entrance hole cut in the side is perhaps the ideal retreat for Poecilotheria as it resembles the tree holes they naturally inhabit. In between are the half bark/half plant habitats for Psalmopoeus, Tapinauchenius, Heteroscodra, Stromatopelma, etc.
This type of jar should provide plenty of ventilation while retaining some level of humidity. It is important to prevent damp conditions and additional air holes should be added as needed to ensure the earth becomes somewhat dry between "watering". Well fed spiders with access to fresh water will survive dry conditions quite well, whereas dampness and stagnant air will quickly lead to trouble. I remoisten the substrate periodically by either misting or carefully overflowing the water dish when refilling. Misting has gotten a bad reputation in arachnoculture because for most it implies overly wet, stagnant conditions or irritating the spider. However, those are the result of improper or excessive misting. I avoid spraying the spider and lightly mist the side opposite of it and the water that trickles down the jar rehydrates the substrate. When there are silken tube retreats, such as with Avicularia, I try to allow droplets to form on the silk if I can avoid the spider.
An increasing number of arboreal tarantula breeders are utilizing plastic cereal storage containers to house and breed adults. These tall and narrow rectangular clear containers, large enough to hold a full box of breakfast cereal, are readily available and are used and modified much as described above for plastic gallon jars. Typical dimensions are 3-4 in [7.5-10 cm] wide (what we will call the front and back), about 10 in [25 cm] deep (the sides) and 12 in [30 cm] tall. There are just a few additions to the gallon jar modifications you will want to make to make these suitable not only for successful husbandry, but also breeding and egg sac production/incubation. First, if you are going to allow eggsacs to be maternally incubated you will need to ensure that ventilation holes are tiny or fabric/mesh covered to prevent spiderling escape. Second, to minimize stress to the occupant part of the container should be darkened so that the retreat (which we are going to make of the back third of container) is protected from light. The easiest way to do this is to tape black plastic (easily cut from a trash bag) around the entire back half of the outside of the container, extending half way forward on the sides. Alternatively but slightly more permanently, dark cloth tape may be affixed to the container so the back and rear portion of the sides is covered. Thus, the front and front half of sides remains transparent so you can see into the container when it is on a shelf, but the back is darkened so the spider's retreat is dark. Finally, the retreat is made by affixing a vertical piece of cork from side to side and from the bottom up to about 1.5 in [3-4 cm] from the top. The cork used is not the cork bark so often used in terraria for arboreal tarantulas, but rather thin cork panels (ca. 1/4 in thick) that are often sold in 12 in [30 cm] squares like tiles. Hot glue or aquarium silicone can be used to hold it in place. With this method the back third of the container becomes the retreat, and the retreat's opening is the 1.5 in or so space between the top of the cork panel and the container's lid. If you want to get a bit fancier you can glue a piece of cork panel that fits snugly from side to side and bottom to top and then cut a smaller U-shaped slot-like opening at the top that is just large enough to allow the female to move from the front of the container to the back retreat.