Tarantulas
Beyond Webs – Swimming, Spitting and Other Spider Hunting Methods – Part 1
Oct 21st
Hello, Frank Indiviglio here. Silk webs are amazing innovations, and the “sit and wait” tarantula stategy is remarkably effective…but among the world’s spiders we also find a mind-boggling array of other hunting techniques. Some of these odd hunters, such as Fishing, Jumping and Trapdoor Spiders, occasionally appear in the trade…all are worth a closer look.
Tarantulas (Mygalomorphs) and Their Relatives
Tarantulas are the best known of the Mygalomorphs (spiders distinguished by, among other things, fangs that strike downward as opposed to side-to-side). Some relatives stray from the “sit and wait” strategy: More >
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Loading ...Insects, Spiders, Other Invertebrates Have Distinct Personalities – New Research
Oct 4th
Hello, Frank Indiviglio here. Most invertebrate keepers have noticed that individuals of the same species often behave quite differently under the same circumstances. For example, one Giant Bird-Eating Spider might feed in broad daylight and be content to remain in the open, while another refuses to eat unless provided with a deep burrow and complete darkness – I can recall countless similar observations. Does this mean that these “simple” creatures have personalities? According to a recent study, the answer may be “yes”…
How Does One Test Insect Personalities?
An article published in the September, 2010 issue of The Proceedings of the Royal Society (B), reveals that individual insects exhibit distinct personality traits, and that these traits remain consistent in different situations. More >
(No Ratings Yet) Loading ...Invertebrate Health – Mites in Scorpion, Millipede and Tarantula Terrariums
Apr 2nd
Hello, Frank Indiviglio here. I’m often contacted by Arachnid and millipede owners who are concerned about the tiny white “specks” that they notice crawling about their terrariums and on their pets. In almost all cases, the little beasts turn out to be relatively harmless Mites. Mites are actually Arachnids, related to spiders and scorpions, and are unique in the incredible diversity they have attained – over 45,000 species have been described, with many more than that likely remaining to be “discovered”. More >
(+2 rating, 2 votes) Loading ...Snake and Spider Fears and Phobias – Instinctive or Learned
Dec 9th
Hello, Frank Indiviglio here. A great many people are fearful of snakes and spiders, often to a seemingly unreasonable degree, and without any prior negative experiences. Researchers have long sought to discover if people possess an inborn, instinctual aversion to these creatures, or if learning is involved.
Living Near Venomous Animals
My own view has always been that it makes sense for people living in the tropics to avoid all snakes and spiders, and I’ve observed that this lesson is taught to children early in life in many places.
There are still over 10,0000 snakebite deaths yearly worldwide, and in areas of high species diversity it is nearly impossible to distinguish all venomous from harmless species (in recent times, 2 renowned herpetologists were killed by snakes not know to be venomous). On my first research project in Costa Rica, I foolishly believed that I would be able to identify many of the snakes and spiders I might encounter. My first nighttime walk through overgrown scrub quickly taught me otherwise!
Another important point to bear in mind is that animals, especially snakes and spiders, are drawn to homes and gardens due to an unnaturally high density of prey (rodents, insects) and in search of shelter. During the dry season in Venezuela, I collected numerous treefrogs, bats and spiders indoors.
Snakes and Primate Evolution
So, based on my experiences, I leaned toward a learning-based explanation. However, recent work at UC Davis has revealed a possible evolutionary explanation to snake aversion among monkeys and, it is theorized, humans.
Fossil and DNA evidence indicates that large snakes may have been among the first serious predators of modern mammals, and were possibly the driving force behind the development of keen eyesight in Primates. The evolution of the Primate vision system seems linked very closely to fear and vigilance receptors in the brain. As Primates became better at spotting snakes, snakes developed more effective camouflage, and so on.
On Madagascar, where large snakes are absent, Primates (lemurs) have not developed the excellent vision possessed by their relatives on mainland Africa.
Most primates do indeed react with “instinctive” fear upon seeing a snake for the first time. However, I have noticed that a great many creatures, ranging from rodents to elephants, treat novel objects with caution, however harmless they might be.
Research Involving People
Experiments involving people have yielded mixed results. Studies conducted at the Universities of Virginia and Queensland has shown that snakes and spiders draw far more attention from human observers than do other potentially deadly animals or objects.
But many of us have (or, at least, I have!) seen toddlers squeal with delight when presented with a spider or snake…yet they will become quite scared if they see an adult express fear.
One thing I’ve noticed is that snakes and spiders have “odd shapes” (except to herpers!)…I wonder if this draws attention; and anything that moves suddenly can startle an observer, especially if it is new to that person.
Teach Them Early
It seems we must wait awhile for answers that may help people overcome their fears and view our cold-blooded friends more reasonably. Until then, please do your part to introduce the next generation to nature early…the little guy pictured here will have no excuses for disliking herps – I’m starting him out on amphibians, and working my way up the “fear scale”!
Further Reading
You can read more about some of the research mentioned here.
Please write in with your questions and comments.
Thanks, until next time,
Frank Indiviglio
(No Ratings Yet) Loading ...Tarantulas and Other Spiders – Dangerous vs. Beneficial Species – Part 2
Oct 5th
Hello, Frank Indiviglio here. In Part I of this article, we learned that less than 1% of the world’s 40,000+ spider species are dangerously venomous. Today I’d like to highlight their valuable role as insect predators and point out a few reasonable precautions that should be taken when keeping spiders in captivity.
Hunting Methods and Diet
Spiders consume animals ranging from mites to birds. Not all ensnare their prey in webs…some hunt by running (wolf spiders), 
swimming (European diving bell spider), spitting silk (spitting spider), hiding in flowers (crab spider), throwing webs (bolas spider), luring fishes while floating (fishing spiders) or rushing from burrows fitted with hinged doors (trap door spider).
However, all spiders consume insects, including agricultural pests and disease-bearing species, to some degree. Field research has shown that harmful flies comprising over 60% of the diet of certain web-building species. It is estimated that the weight of the insects consumed yearly by spiders in New Zealand exceeds that of the island’s human population!
Precautions – Bites and Urticating Hairs
The fact that so few spiders are dangerous to people should not be taken as a license to ignore caution when dealing with them. Just as with bees and other venomous animals, allergic persons can be injured or killed by the bites of relatively benign species, and potentially fatal infections can be associated with the bite of any animal.
Also, many tarantulas shed urticating (irritating) hairs when disturbed or even when just moving about. A colleague of mine underwent major surgery to remove such hairs, deposited on his hand by a “tame” red-kneed tarantula, from his eye.
That being said, I have kept native and exotic spiders since childhood, and have never been bitten – because I do not pick up spiders with my hands. I urge you to handle spiders, if at all, with plastic tongs or by ushering them into a container.
Further Reading
The diving bell spider is certainly one of the world’s most interesting invertebrates – living within a submerged shelter that exchanges oxygen with the surrounding water and swimming after small fishes! To read more, click here.
Please write in with your questions and comments.
Thanks, until next time,
Frank Indiviglio
Misumena vatia with wasp image referenced from wikipedia and originally posted by Olei.
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