New World Arboreal Tarantulas
Lucian K. Ross
All New World arboreal tarantulas (Theraphosidae) are members
of the Aviculariinae SIMON, 1874 subfamily. Six genera are currently
Avicularia LAMARCK, 1818 (53 species/2 sub-species)
Ephebopus SIMON, 1892 (4 species)
Iridopelma POCOCK, 1901 (3 species)
Pachistopelma POCOCK, 1901 (2 species)
Psalmopoeus POCOCK, 1895 (11 species)
Tapinauchenius AUSSERER, 1871 (9 species)
Due to the rarity of members of the
genus Pachistopelma in the arachnocultural hobby and the
terrestrial habits of members of the genus Ephebopus, neither genus
will be discussed in this article.
The taxonomy of Avicularia is
highly problematic and the species and sub-species within this genus are
those that are currently recognized. However, as the systematics and
taxonomy of the species and sub-species within this genus are mostly
incomplete or unknown at this time, many future taxonomic changes are
New World arboreal tarantulas range from
Mexico throughout Meso and South America and several of the Greater and
Lesser Antilles Islands. Although several species were described from
North America, to date, no preserved material (specimens in private
collections or museums) or natural populations (in the wild) have been
discovered to confirm the past or present existence of the described
species in North America.
All New World arboreal tarantulas
inhabit tropical rain forest/forest systems throughout their range.
Typical habitat includes, but is not limited to, tube or tent webs in/upon
living and dead standing timber, exposed root systems, undergrowth,
bromeliads (typically epiphytic plants), manmade structures, road banks
and tall grass.
New World arboreal tarantula species vary in size from several
small Avicularia and Tapinauchenius species, which may only
attain leg spans of 7.5 cm (3") to several members of the genera
Avicularia and Psalmopoeus, which may attain leg spans of
17.5 cm (7") or slightly larger. Most species will average in size from 10
cm (4") to 12.5 cm (5") in leg span and are less robust in body size
comparatively sized terrestrial species.
Most are colourful (Avicularia, Iridopelma and
Tapinauchenius) or patterned (Psalmopoeus) and many are
coloured in bright metallic hues of bronze, pink, green, blue, purple or
gold on the carapace, trochanters and femurs of the legs (several species
within the various genera).
Members of the genera Avicularia
and Iridopelma are covered in both short and long setae with a
profusion of longer setae on the legs (primarily on legs III and IV) and
around the anterior and lateral dorsal surfaces of the abdomen.
Psalmopoeus and Tapinauchenius species are less profusely
adorned with long setae than the members of the two above genera, with the
abdomens of most species being densely covered in short, silky setae. The
setae covering the legs of many species within these two genera give these
tarantulas a sculpted, streamlined appearance in comparison to the members
of Avicularia and Iridopelma, which typically appear more
robust and "shaggy" in appearance. The males of all species within the
above four genera currently available in the hobby are more profusely
covered in longer setae than the females. Another characteristic feature
of the males of many species of Psalmopoeus and Tapinauchenius
is that the length of the legs in sexually mature specimens is greatly
disproportionate to the length of the much smaller body, giving these
tarantulas an almost comedic appearance.
Arboreal tarantulas are easily
differentiated from their terrestrial cousins by the typically elongated
abdomen and the presence of laterally widened and thickened scopulate pads
on the metatarsi and tarsi. All tarantulas possess these pads, which are
comprised of thousands of minute "hairs" (scopulae). The greater sizes of
these pads on arboreal tarantulas are evolutionary modifications for life
on a vertical surface. The enlarged pads allow arboreal tarantulas to move
over smooth surfaces and the ventral surfaces of tree braches, as easily
as terrestrial tarantulas move across the ground. It has also been
reported that some New World arboreal tarantulas may jump from vertical
surfaces (tree trunk, limb, etc.) to a stream or river below to elude
predators. Such enlarged pads would surely assist the tarantula in moving
quickly over the water's surface.
Aside from several popular members of the genus
Avicularia, that are maintained in captivity and are known
for their complacent and calm behaviours, the majority of the members of
the remaining five genera, and several Avicularia species common in
the arachnocultural (arachnoculture – keeping, maintaining and breeding
arachnids in captivity) hobby are typically high-strung, fast, nervous,
unpredictable and display varying degrees of defensiveness when disturbed,
startled or handled. Defensive behaviours range from the tactile
introduction of abdominal urticating setae by members of the genera
and Iridopelma (Psalmopoeus
and Tapinauchenius species do not possess urticating setae) to
striking with the forelegs and/or rapid single or multiple bites (all
species may exhibit these behaviours). Members of the genera
Iridopelma, Psalmopoeus and Tapinauchenius should never be
handled. Many Avicularia species are popular in the arachnocultural
hobby and are widely known for their calm temperaments and tolerance of
disturbances. However, there are several species such as Avicularia
caesia, A. versicolor and A. huriana, which may be
high-strung, nervous, unpredictable and some specimens bite with
little provocation. Fortunately most Avicularia species, even those
listed above, are easy to work with and maintain in captivity.
Some suggested Avicularia species
for the novice:
BAUER, 1996: Peru
(LINNAEUS, 1758): Brazil, French Guiana,
Guyana, Trinidad and Venezuela
MELLO-LEITAO, 1923: Brazil
AUSSERER, 1875: Colombia and
Avicularia minatrix POCOCK, 1903: Venezuela
Avicularia purpurea KIRK, 1990: Ecuador
Avicularia urticans SCHMIDT, 1994: Peru
Aside from the species listed above, the
following species are also commonly available in the hobby:
TESMOINGT, 1999: Peru
Avicularia geroldi TESMOINGT, 1999: Brazil
*Avicularia huriana TESMOINGT, 1996: Ecuador
*Avicularia caesia (C.L. KOCH, 1842): Puerto Rico
(WALCKENAER, 1837): Guadeloupe, Martinique
& Dominica Islands
POCOCK, 1901: Brazil
*Iridopelma zorodes (MELLO-LEITAO, 1926): Brazil
POCOCK, 1895: Trinidad
SAAGER, 1994: Venezuela
PETRUNKEVITCH, 1925: Panama
(KARSCH, 1880): Costa Rica
CAPORIACCO, 1954: French
AUSSERER, 1875: Venezuela
(C.L. KOCH, 1842): Brazil, Peru, Surinam
*These species are capable of sudden
bursts of movement and are typically
unpredictable in temperament and may
bite if startled, disturbed or handled.
Other factors to consider when
contemplating keeping arboreal tarantula species is that all species are
capable of sudden bursts of high-speed movement and all are capable of
making short lateral jumps of 25 cm or less when annoyed or startled. Some
species such as Avicularia minatrix are highly accomplished jumpers
and will jump with little provocation. Members of the genera Avicularia
and Iridopelma possess urticating “hair” (setae) which are used
in defence. These "hairs" (not true hairs that grow) are barbed and when
the tarantula’s abdomen makes physical contact with the skin of another
animal the urticating setae are imbedded into the predator’s
In captivity, most New World arboreal
tarantulas are shy and retiring, and are generally inactive during diurnal
(day light) periods. As most tarantula species are active during
crepuscular (dawn and dusk) and/or nocturnal (night) periods in the wild,
most will replicate this behaviour in captivity. Few specimens will be
seen moving about their containers during day light periods. Most will
begin actively moving about their containers during the late evening
hours. Many will become active during overcast days or if maintained in
vivaria or in rooms with decreased light levels.
Growth and Longevity
All New World arboreal species exhibit fast to moderate growth
rates with typical female specimens reaching sexual maturity within 22 to
30 months, and typical male specimens within 14-18 months. Atypical
specimens may reach sexual maturity several months earlier or later than
stated above. In captivity, growth rates are dependent on many factors
such as temperature, diet, number of feedings per week, amount at each
feeding, etc. Tarantulas maintained at higher temperatures and offered
large numbers of prey items three to four times per week will normally,
exhibit faster growth rates than tarantulas maintained at lower
temperatures and fed sparingly.
Life spans for most tarantula species
are unknown, but based on hobbyist reports and available information in
various publications, the typical life span for New World arboreal species
is believed to be in the range of 7 to 14-years.
To date, those few individuals that have reported rare bites
from New World arboreal tarantula species have indicated nothing more than
the initial pain caused by the mechanical action of the bite itself, and
minor local effects such as redness and swelling at the site of the
SocialityAlthough it has been suggested that some
Avicularia species may live as a group and exhibit limited social
behaviour; based on personal experiences and the reported experiences of
others, such communality is both, short-lived and eventually terminates in
a situation where one or more of the tarantulas is captured and killed by
another member of the community. Although some species can be maintained
in a communal set-up for varying lengths of time, the behaviours exhibited
by tarantulas in such a set-up is that of tolerance; not
All New World arboreal species
are hardy and easy to maintain in captivity with no special requirements.
As for any arboreal species, the main requirement is a vertical piece of
structure such as a slab or tube of cork bark or other barks that the
tarantula can construct a tube web upon, behind or within. Other options
are available such as short sections of dead tree limbs where the wood is
decayed and can be removed to provide a hollow space for the retreat of a
arboreal species, plastic PVC piping or small wooden birdhouses affixed to
a wall within the vivarium. Always use aquarium silicone sealant to secure
a vertical structure to the floor and/or wall of the vivarium to avoid the
possibility of the structure toppling over when the vivarium or container
Research, research, research! Find out as much information on
the tarantula species you are interested in acquiring and on tarantulas in
general. A basic understanding of the tarantula's behaviours, anatomy,
habits, habitat types, moulting and growth will allow you to not only
better understand your tarantula(s), but will provide answers to many of
the questions that the novice keeper will want answered. Whether you
acquire one or more books, surf the web for tarantula-related sites, join
a discussion group or one or more arachnocultural (hobbyist) societies, do
enough initial research to allow you to acquire a basic understanding of
tarantulas, their behaviours and their requirements in
Tools and equipment
Before acquiring your first tarantula, there are several basic
tools and pieces of equipment that will make maintenance of your tarantula
and its environment easier for you, and less stressful for your tarantula
by decreasing disturbances within the vivarium.
The following items are
Several long-handled wooden spoons
for removing prey remains, substrate manipulation,
At least, one pair of forceps in
each of the following sizes: 17.5 cm (7"), 25 cm (10") and 30 cm
(12"). Useful for removing shed exuviae (moults), prey remains and for
the manipulation of enclosure decorations.
One or more long-handled, soft
bristled paintbrushes. These are indispensable for manipulating your
tarantula into its retreat during vivarium maintenance.
Several empty clear plastic
deli-cups with clear lids (the 472 ml (16-oz.) size is ideal). Useful
in capturing any escapees and as a temporary holding container for
your tarantula during complete enclosure cleanings (e.g. when you need
to replace the substrate and the tarantula has to be
Plastic spray bottle with an
adjustable spray nozzle (available at most garden centres) to mist
your tarantula's container (especially for smaller specimens
maintained in small containers such as vials where a water bowl cannot
be added due to size limitations) to supply an additional source of
drinking water (many arboreals will refuse to drink out of a water
bowl and will prefer to drink water off of the walls of the vivarium)
and to help maintain moderate humidity levels in the closed
environment within the container/vivarium.
A standard notebook for recording
moult dates, interesting behaviours, etc.
Removable adhesive labels for your
tarantula's container. Typical useful information to place on such a
label is: species, date of acquisition, size at acquisition,
geographic range and whether the species is captive-bred (cb-the
tarantula(s) was bred in captivity), captive-raised (cr-the tarantula
is the offspring of a gravid female imported from the wild) or
wild-caught (wc-taken from the wild).
If you've acquired a spiderling or
immature specimen then, it is also advisable to plan in advance and have a
larger container or series of appropriately sized containers to
accommodate the tarantula as it moults and grows.
Unlike their terrestrial kin,
arboreal tarantulas only need a thin layer of substrate in their
container/vivarium to provide a natural appearing environment, retain
moisture and as material to use to conceal their retreats. Many arboreal
species, after constructing a web retreat will add various materials such
as substrate, bark chips or sphagnum moss to the outer surface of their
web to camouflage and conceal it from predators. In captivity, this
behaviour may decrease the likelihood of captivity-related stress, by
providing the tarantula with a secure retreat in which it feels safe. As
for substrate types, good substrate choices are any of the following, or a
combination of them: premium grade topsoil, potting soil, peat or
vermiculite (some arboreal specimens refuse to walk on vermiculite). A
good mix is one that contains 50-60% topsoil and 40-50% peat (or, vice
mixture will retain a moderate amount of
moisture and due to the acidic nature of the peat, will retard the
decomposition of prey remains. As peat is hard to re-hydrate (wet), do not
allow any substrate with peat to thoroughly dry out.
A few advantages and disadvantages in
using the various substrates listed above:
Topsoil and potting soil: heavier
than other substrates. Provides a "natural" look to the vivarium
Peat: Hard to re-hydrate when dry.
Lightweight and the acidic nature of peat retards the decomposition of
prey remains, moulds and fungi.
Vermiculite: Many tarantulas dislike
walking on vermiculite. It has an "unnatural" appearance. Lightweight.
High moisture retention.
Contrary to the belief that arboreal
tarantulas require exceptionally tall containers to thrive, all arboreal
tarantula species can be maintained in enclosures where the height is
equal to the outstretched leg span of the tarantula, plus fifty percent of
that measurement. A standard 37 L (10-Gallon) aquarium offers more than
enough space for a arboreal tarantula with a 15 cm (6") to 17.5 cm (7")
Suggested containers, sizes and basic
Leg span up to 2.5 cm
40 to 50-dram clear plastic vials with
removable lids. Using a heated nail or ice pick, melt 3-5 small holes in
the vial and the lid to allow ventilation.
1 cm (0.5") of moistened
Small piece of cork bark or other
bark 1 cm (0.5") less than the vial’s length.
Small wad of dried sphagnum moss (to
retain moisture in the substrate and for the tarantula to use to
camouflage its retreat.
Leg span from 2.5 cm (1") to 7.5 cm
944 ml (32-oz.) clear plastic
deli-containers with clear plastic lids, glass or plastic jars, small "Pet
Pal" type plastic vivaria or small glass vivaria. Supply ventilation holes
in any of the listed containers to provide airflow.
2.5 cm (1") to 5 cm (2") of moistened
Vertical piece of cork bark, other
bark or structure i.e., cork bark tube, hollow tree limb,
A wad of dried sphagnum moss (see
Bottle cap, jar lid, small plastic
deli-container (in larger containers) or another small container to use as
a water dish for the tarantula and to assist in adding humidity (via the
evaporative process) to the closed-environment.
Leg span from 7.5 cm (3") to 15 cm
3.7 L (1-Gallon) glass or plastic
jars, medium to large "Pet Pal" type vivaria or 20 L (5.5-Gallon) or 37 L
(10-Gallon) glass vivaria. If using glass vivaria and commercially
produced mesh screen lids, the lids should be modified as the tarantula's
tarsal claws may become trapped in the mesh causing the tarantula harm or
possibly death. Modify the lid by replacing the mesh screen with a piece
of Plexiglas (drill 10-12 holes into it to provide ventilation). Hardware
cloth can also be used as a substitute, but ensure that 50-60% of this
material is masked with plastic to avoid excessive loss of humidity
(aquarium sealant can be used to fix the material in place). Only use lids
that can be securely locked onto the vivarium.
5 cm (2") of moistened substrate (in
larger vivaria, adding a thin layer of moistened sphagnum moss over
50-80% of the substrate will allow a greater amount of moisture to be
retained in the substrate for a longer period of time, decreasing the
frequency of mistings per week).
One or two large vertical slabs of
cork bark, cork bark tubes or other structure material.
A water dish. A good container to
use for a water dish is a clear plastic 236 ml (8-oz.)
Additional vivarium decorations:
potted plants, artificial plants and vines, a piece of cork bark on
top of the substrate. Keep the addition of extra vivarium decorations
to a minimum as too many decorations will make maintenance a real
chore and will afford the tarantula too many hiding places making it
difficult to keep track of your tarantula's location when you are
working in the vivarium. A potted Pothos plant in a corner of
the vivarium makes a wonderful vivarium addition and along with the
green of the sphagnum moss, adds a great deal of colour and life to
the closed environment within the vivarium.
Key Maintenance Points
Have fun with decorating your
tarantula's container/vivarium, but keep decorations to a minimum to
avoid making vivarium maintenance a chore and to decrease the number
of hiding places that your tarantula can utilize during
Provide a piece of bark on top of
the substrate as many arboreal tarantula species during various
life-stages may utilize ground retreats. Many young Psalmopoeus
and Tapinauchenius specimens will construct and/or excavate
Add peat if you're using topsoil or
potting soil as a substrate. Its acidic nature will retard the
decomposition of prey remains in the vivarium and it has a moderate
moisture retention capacity.
Add dried sphagnum moss to your
tarantula's container/vivarium. Many arboreals use this material to
camouflage and conceal exposed tube webs. Larger pieces can be placed
on the substrate to retain moisture and add colour to the tarantula's
Keep accurate records of your
tarantula's moults, feeding patterns, interesting behaviours, etc.
This will provide you with a source book of accurate information
regarding the tarantulas in your collection.
Enjoy your tarantula! Spend time in
passive observation learning about your particular spider.
Once your tarantula(s) has attained
a large enough size to be maintained in a larger containers, add a
bottle cap, small deli-container or water dish to supply drinking
water and as an aid in adding moisture (humidity) to the captive
Don’t use more substrate than
necessary in your tarantula's container/vivarium. This will only
increase the weight of the vivarium and offers no advantage for the
keeper or the kept.
Don’t open or remove the lid of any
container/vivarium without first locating your tarantula in the
vivarium. Always be aware of any tarantula's location when working
within the vivarium. Most New World arboreal species can move very
swiftly and may escape if given an opportunity.
Don’t keep any New World arboreal
species in a high-temperature/high-humidity environment with
restricted airflow. Such environments are unnecessary and may be
detrimental to the health and well being of your tarantula. Keep
temperatures in the range of 24ºC (75ºF) to 27ºC(80ºF) and humidity
levels in the range of 70%-80% and always allow a moderate degree of
airflow into the tarantula's container/vivarium.
Don’t keep containers/vivaria in
areas that receive direct sunlight. Temperatures within the captive
environment will increase rapidly and will cause the death of the
tarantula in a short period of time.
Don’t work in your tarantula's
container/vivarium any longer than necessary to complete maintenance.
Keep disturbances to a minimum. When maintenance is completed, always
check to insure that the lid is securely re-attached and locked onto
the container/vivarium to avoid possible
What size tarantula?
What size tarantula you'll acquire as your first specimen will
typically be influenced by your own personal opinion as to your abilities
in working with a certain size specimen, cost and interests.
Spiderlings or small immature specimens
seem the perfect choice for the novice arachnoculturist. Captive bred
spiderlings of many arboreal species are
inexpensive and readily available from
many breeders worldwide. Arboreal tarantulas of this size are also, easier
to house, feed and maintain. Another benefit for the first time keeper is
that he/she will be able to learn about the tarantula by observing its
growth and behaviour throughout its development.
Regardless of the size tarantula you
choose, remember that as an arachnoculturist, it is your responsibility to
aid in the conservation of tarantula populations in the wild by acquiring
captive-bred specimens thereby, supporting captive breeding efforts
worldwide. Acquiring captive bred specimens will lessen collecting
pressures on wild tarantula populations and ease the demand for
wild-caught specimens. Although some wild-caught specimens are necessary
to provide genetic diversity in existing and future breeding groups, there
is little justification in taking hundreds or thousands of specimens
annually from wild tarantula populations. Fortunately, many of the New
World arboreal tarantula species are commonly bred, inexpensive and
readily available in the hobby.
Feeding and diet
All arboreals will accept insect prey such as locusts,
grasshoppers, crickets, mealworms and various species of cockroach. Larger
specimens may accept pre-killed "pinkie" and "fuzzy" mice, anoles
(Anolis carolinensis), prawns, crayfish and pieces of diced beef
Spiderlings and smaller immature
specimens should be offered prey at least 3-4 times per week and larger
specimens 2-3 times per week. The size of prey should not be more than
half the size of the tarantula. As each individual tarantula will exhibit
varying eating habits, the number and/or amount of prey offered can vary
greatly. Offer the tarantula several prey items and those not consumed
within a 24-hour period should be removed.
Never allow living, non-eaten prey items
to remain in the tarantula's container/vivarium during the moult stage as
upon completion of its moult, the tarantula's integument and fangs are
soft, unhardened and pliant and some prey items may attack the defenceless
tarantula, feeding on its unhardened integument causing it injury and
possibly death. If you suspect your tarantula may be in the pre-moult
stage, cease offering prey and remove any prey items from the
If your tarantula begins to refuse food
items placed in the container/vivarium, it may be in the pre-moult stage
(this stage may last several days to several weeks depending on species,
the individual tarantula and its size). It is normal behaviour for
tarantulas to stop feeding during the pre-moult and moult stages and for a
short post-moult period that may last 2-12 days. Once again this depends
on the species, the individual tarantula and its size. If the tarantula
seals itself in its web and shows no signs of an impending moult then, the
environment within the
vivarium may be too dry and/or too hot.
Try a moderate misting or several light mistings over a 2-3 day period to
elevate humidity levels within the vivarium. If your tarantula refuses to
feed and use its retreat, the environment within the vivarium may be too
humid and/or hot. Do not mist - allow the vivarium to dry out for 3-5
days. Both of the above-described behaviours are indicators that the
tarantula is suffering captivity-related stress. Another indicator of
captivity-related stress is when a tarantula is maintained in a
high-temperature/high-humidity environment with restricted airflow. In
this situation the tarantula may interpret the entire vivarium as the
inside of its retreat and may cease using its regular retreat in favour of
remaining in the open. In such environments, the tarantula may exhibit an
increase in defensive behaviours during disturbances in the vivarium, and
may rapidly rush about the vivarium perceiving that a "threat" is within
As always, a 'special' thanks to Richard Gallon for his
ever-valuable and kindly assistance in preparing this article.
Baxter, R. N. 1993: Keeping
and Breeding Tarantulas. Chudleigh Publishing, Ilford, p.
Marshall, S. D. 1996:
Tarantulas and other Arachnids. Barron's Educational Series Inc, New
York, p. 104.
Murphy, F. 2000: Keeping
spiders, insects and other land invertebrates in captivity.
Fitzgerald, London, p. 96.
Schultz, S. A. & M. J.
1998: The Tarantula Keeper's Guide. Barron's, New York, p. 287,
Verdez, J. -M. & Cléton,
F. 2001: Mygales, Découverte Élevage, p. 190 (in French)
Verdez, J. -M., Cléton, F.
& Gérard, P. 1997: L'élevage des Mygales. Atelier Alfortville,
Alfortville, p. 83. (in French)
If the above titles cannot be
located at local pet stores or book-sellers, contact Tim Fitzgerald at
Fitzgerald Publishing Company at
email@example.com or telephone at 020
8690-0597 (London, UK). Fitzgerald Publishing offers a full selection of
arachnid and invertebrate books at very affordable
- An on-line International list for
the discussion of arachnids and other invertebrates at http://www.yahoogroups.com/
- Website for the British Tarantula
Society (UK). Publishes the British Tarantula Society
- Website for the American
Tarantula Society (USA).Publishes the Forum Magazine of the American
- Website for Exotiske Insekter
(Denmark). Publishes Exotiske Insekter magazine.
http://gea.free.fr/ - Website for Groupe d'Etude des Arachnides
To contact the author, email: Lucian K.