Famous Faces of the Desert – Tarantulas

In the interest of full disclosure, I’d like to make it clear that I am not a fan of spiders. All those skittering legs, yucky webbing and fierce fangs just make my skin crawl. This attitude is the direct result of a horrifying incident with a giant spider and its web when I was a child in Panama. I can’t bear thinking about it to this day.

Photo by Valerie, Customer Service

Having said all that, I do rather like tarantulas. After numerous encounters with these spiders, both in the wild and as someone’s pet, I see that they are gentle and delicate creatures. They are probably the most misunderstood of all the iconic desert creatures we have here in Arizona.

Unlike other desert creatures I have talked about in this series, I have not encountered tarantulas in or around our office. However, most of our crew has had them around their homes; so I asked for pictures from them. Mike, our Shipping Manager, contributed an image of a large black one found in his garage and Valerie, Customer Service, donated one of a lovely grayish specimen. These two pictures, taken just a few miles from each other, show the variety of tarantula species in our area.

Photo by Mike, Shipping Mgr

Despite their rather fearsome appearance and their unwarranted reputation as being dangerous, the truth is tarantulas are more shy and reclusive than anything else. They live solitary lives in holes, burrows or crevices and rarely venture far from them. Around here, if you find a hole about the size of a quarter, it may be a tarantula hole. If you see silk in or around the hole, it is actively occupied. The silk helps prevent cave-ins and makes the perfect nesting material. They often extend the silk lining outside the entrance. This outside webbing has two purposes: waterproofing and an early warning system. Tarantulas do not like water and their silk helps keep their burrows dry. If a burrow floods, the tarantula will flee. This is one reason that they are more
likely to be seen during monsoon season here. Outside webbing also serves to let the spider know that prey is nearby. They can sense vibrations and the slightest touch to the webbing will send the tarantula out to snag its dinner. When it is time to hibernate for the winter, the spider will mix the silk with a little dirt dirt and create a plug for the opening.

A tarantula resting on its silk

Females will always be in or very near their burrows, but males will head out looking for love during mating season (generally September-October). In some places, tarantula males head out in large numbers, making for an unsettling display of devotion to reproduction. Once a male finds a female’s burrow, he will “knock” on the silk around the door. The female will rush out and, in that split-second, make her decision to mate with him, eat him or both. After the long trek to get to her, it is the worst kind of blind date. With what he goes through for love, it should come as no surprise that females live twice as long as males.

Although their bite can be painful, a tarantula’s venom is not dangerous to humans. Because they feed on small prey like other insects, arthropods and the occasional small lizard or mouse, they have no need for venom strong enough to disable or kill a large being. Unless the person has a severe allergic reaction, a tarantula bite is no more serious than a bee sting.

The hairs on a tarantula can cause a person more trouble than their venom. They have hundreds of hairs on their upper abdomen called urticating hairs that are used as a defense mechanism. They will flick these barbed hairs at would-be tormentors. Once lodged in their target, these hairs are extremely irritating and difficult to remove. They can cause real damage if embedded in the eye or inhaled. Just give them their space and they will give you no trouble.

Tarantulas have very thin skin, especially in the abdominal area. This makes them very vulnerable to damage from falls. A height of less than a foot can kill a tarantula. This makes for another good reason not to handle them.

While they cannot handle falls, losing a leg is something most tarantulas can overcome. They will simply regenerate a new leg the next time they molt. Never one to turn down a meal, the tarantula may even eat its detached leg. Since males rarely molt once they reach sexual maturity, it will be the females or immature males re-growing legs. We used to have a very large (about 4½”) 7-legged fellow who hung out in the tree by our front door.

Tarantulas appear in many legends around the world  and in many myths of native peoples. Underscoring its importance as an essential part of our Southwestern world, the Navajo, Zuni, Apache and Pima all have traditional lore surrounding the tarantula.

When it comes to predator and prey, tarantulas are equal parts of each. They are valuable predators for pest insects such as cockroaches, but they are also preyed upon in all stages of their lives. Ants invade their burrows and feast on their eggs and large predators gobble them up when they are old enough to leave their burrows. The most terrifying and gruesome nemesis of a tarantula is the Tarantula Hawk (Pepsis spp).These insects prey on and parasitize the spider as part of their

Tarantula hawk

reproductive cycle. I will save the specifics of their predation for one of my October blogs on insect mummies and zombies. Suffice to say, it’s pretty gross.

Usually, at this point in the blog, I would direct you to ways to control the creature I’ve been discussing. With tarantulas, however, I have no control recommendations. These benign creatures mean you no harm and can easily be guided away from you, your yard and your pets.

Submitted by Pam

This Summer’s Kiss Is One To Miss

One of the least popular insects that appear in our desert over the summer months is the Kissing Bug (Triatominae, subfamily of Reduviidae), also known as conenose bugs, vampire bugs or Mexican bed bugs. The variety of names reflects the fact that there are many (up to 85) species in the Americas, with about 15 in the United States. 

As temperatures have warmed across the continent, kissing bugs have been able expand and thrive in new areas. These 6-legged, winged insects vary in color from a light brown to black and have red, yellow or tan markings along their abdomens. They are small (about ½-1” long) and rather flat (unless they’ve recently fed) with an elongated oval shape. They can be easily mistaken for assassin, wheel or stink bugs (and even cockroaches).

And now for the gory stuff: Kissing bugs feed on mammalian blood through all five stages of development, from nymphs through adults. Females lay eggs between June and September and their offspring hatch out and begin seeking blood in 1-3 weeks. Although they can go long periods without feeding, these bugs feed more regularly when hosts are readily available. A single feeding can last a disturbing amount of time: 20-30 minutes. Their preferred hosts include dogs, opossums, coyotes, mice, skunks, raccoons and humans. 

Kissing bugs get their name from their proclivity for biting people on the face, especially around the eyes and lips. They are able to get so close without being detected because they are nocturnal and seek out sleeping prey. They then inject an anesthetizing agent before they draw blood, so the sleeper is usually not even aware of the bite when it happens. They will wake up with unexplained marks or welts on their skin.

Although kissing bugs are undoubtedly blood-suckers, researchers have found that they also feed on plants. They source sugars and proteins from plants and this seems to keep them healthier and more energetic so that they can bite more people.

Kissing bugs pose a danger to people because they can carry the parasite Trypanosoma cruzi, which causes Chagas disease. This serious disease is found all over Mexico, Central and South America. As many as 21,000 deaths a year are attributed to Chagas disease in these regions. While there have been some cases in the United States, it is, thankfully, rare here. This is due to the type of species we have here. Chagas is spread through the bug’s feces. They defecate while feeding and when a person wakes up and scratches at the bite, he/she introduces the infected poo into their body. Kissing bugs in Arizona don’t exhibit the type of behavior that spreads the disease; they don’t defecate where they feed.

Chagas disease may not be a serious threat to people here, but kissing bugs can still be dangerous. People can be allergic to the saliva (and, thus, the bite) of these bugs. While a very small number of people are affected from the first bite, the trouble usually begins with subsequent bites. It is then that an allergy can develop. These allergic reactions can vary in severity from flushed skin to nausea and vomiting to life-threatening anaphylaxis. The Centers for Disease Control and Prevention has a great deal of information on Chagas here: https://www.cdc.gov/parasites/chagas/

There is no immunotherapy available to protect you from developing dangerous allergies to kissing bugs. If you have reason to believe they are in your area, your best course of action to protect yourself is to keep them out of your house. They will fly (but not very far) looking for their next meal, so to make it more difficult for them:

• Seal any cracks or crevices that lead from outside into your home (in and around doors, windows, eaves, etc.)
• Clean up wood, rock piles and animal nesting areas in the yard and move items they can hide in away from the house.
• If you dry clothes on the line, bring them in as soon as they are dry.
• Keep your pets indoors, especially at night.
• In Arizona, pack rats and their nests are favorite lodging places for kissing bugs. While pack rats are difficult to control on their own, ridding yourself of them will also lessen your chances of having kissing bug problems.

To get rid of the kissing bugs in your yard, try a combination of granules as a barrier and a spray insecticide to cover the area. Essentria™ G Granular Insecticide and EcoPCO® AR-X Multi-Purpose Insecticide would be good choice.

The University of Arizona College of Medicine is currently researching kissing bugs and is asking for input from the public. They are seeking live bugs as well as individuals who have been bitten. They are asking that, if you come across a kissing bug, do not touch or squash it. Place a glass or other container on top of it for 24 hours and then seal the bug inside and contact them. 

-Contributed by Pam @ ARBICO Organics

We Love Our Monsoons.

Summer in Arizona: ridiculously hot days, wild monsoon storms, terrifying haboobs, exquisite sunsets and all sorts of critters out wandering around. It is not a time for the faint-of-heart. But, for us true desert creatures, this is the best time of year. The primordial joy of rain after extended months of dryness is shared by flora, fauna, humans and insects alike.

What we call monsoon season runs from late June through September. Our storms are caused by a seasonal shift in winds that draws moisture-rich air from the Pacific Ocean and Gulf of Mexico up into Arizona. This air hits the super-hot air in the valleys and shoots up the mountains into the atmosphere. Once there, it builds and builds until it rolls back down as an action-packed storm. Watching the storms build is a favorite pastime of all us Arizonans, but the changes they bring to desert are life-affirming.
Desert dwellers, of all species, can sense and smell the rain as it’s coming. This earthy smell of rain as it lands on dry soil is called petrichor. In Tucson, where I live, we also recognize the beguiling scent of the creosote bush.

 Contributed by Valerie @ ARBICO Organics

Monsoon rains provide almost everything in the ecosystem with renewed life. Plants green up and fruit ripens, providing food for mammals, birds and insects. All this additional fodder makes this the ideal time for mating, so the parade of mating creatures comes out during monsoons. Arizona is ranked 3rd in the country for biodiversity by The Nature’s Conservancy and, at times, it seems like they are all out after a good, hard rain. Lizards, snakes, beetles, arachnids, toads and mammals come to feed and mate. This is the only time to see our most publicity-shy desert dwellers, as they stay hidden the rest of the year.

At the top of the list of spectacular monsoon creatures is the Gila Monster (Heloderma suspectum). These lumbering beasts are the largest lizards in North America and can grow up to 2 feet long. They are one of only two venomous lizards in North America and the other, the Mexican beaded lizard, is a close relative. Gila Monsters spend 90% of their time in underground burrows and only emerge after rains to drink, bathe and mate. It is during this search for a partner, when their biological impulses outweigh their natural reticence, that people run into them. This year has been an active one for Gila Monster sightings - we had one crawling across our office parking lot one day, a co-worker had two loudly mating in her driveway and my Facebook feed has been full of pictures of Gila Monsters in garages, on porches and by swimming pools.

Gila Monster

What The Heck Is That Monstrosity?

I recently had a knee injury and was ordered to stay off it for a couple of weeks. During my forced vacation, I spent most of my time on the living room couch. From that vantage point, I could watch the dogs going about their business in the backyard. 

One evening I noticed that Bob, our large Shar-Pei/Lab mix, was acting strangely. He was dancing around, jumping and pawing at something on the ground. He looked exactly like a fox hunting for mice under the snow. You could almost see the thought bubbles over his head saying, “What the heck is that monstrosity?”.

Bob is generally a dignified and somber older gentleman and this behavior was decidedly unusual for him. So, ignoring the admonishments of my family to stay put, I hopped over to the door to see what had poor old Bob so upset. 


What I saw made me laugh – Bob had come across a particularly large Palo Verde Beetle. I have seen large humans freak out when they see these bugs, so it was perfectly acceptable to me that our dog would go bananas over it. As I stood there laughing, Bob took one more manly leap and crushed the beetle, then quickly ate it. What had been funny was suddenly just gross.

Palo Verde Beetle - Photo courtesy of Jen Ragan