africanized bees

The most dangerous venomous animals of the Southwest

Speckled-rattlesnakeThe southwestern desert has a reputation for venomous critters, but which are most dangerous? I attended a lecture at the Arizona-Sonora Desert Museum given by James W. Cornett, a biologist, author, and emeritus Curator of Natural Science at the Palm Springs Desert Museum. Cornett has studied venomous animals for over 30 years and gave us a list of what he considers the thirteen most dangerous animals.

This list is subjective and includes consideration of the toxicity of the venom, the amount of venom injected, the possibility of an allergic reaction, the abundance of the animal, and the probability you could actually encounter the animal. Here is his list from the least dangerous to most dangerous:

13. Tarantulas. The venom is generally not dangerous to humans and it takes much provocation to get a tarantula to bite you.

12. Centipedes. Some of these can get over 10 inches long (but most are about 5 – to 8 inches) They deliver venom by pinching with its front legs. One death has been attributed to a centipede bite.

11. Velvet ants (actually wasps). These look fuzzy and cute but deliver a very painful bite.

10. Gila monster. These lizards are venomous but it takes some provocation to get them to bite you. (Note: that provocation can be trying to be nice and carrying one off the road so that it doesn’t get run over.)

9. Coral snakes. The coral snakes in the Southwest are generally small. More deaths occur in the East where the snakes are larger.

8. Cone-nosed bugs (aka Kissing bugs). Bites from these bugs can produce an allergic reaction and can transmit Chagas Disease, a chronic and debilitating protozoan infection. Cone-nosed bugs feed on the blood of other animals, mostly rodents.

7. Ants. Swarming ants, by their large numbers can deliver painful bites and cause allergic reactions.

6. Scorpions. Most scorpion stings in the southwest are not dangerous. However, bark scorpion venom is dangerous to humans.

5. Brown (recluse) spiders. The venom is very persistent and causes tissue damage.

4. Wasps.

3. Black Widow spiders. Drop for drop, black widow venom is the most toxic of any animal in the southwest. And now, we are seeing more Brown Widow spiders coming into the area.

2. Rattlesnakes. This venom does great tissue damage and two species, the Tiger rattlesnake and Mohave rattlesnake also have neurotoxic venom. By the way, there are 18 rattlesnake species common to Arizona.

And the most dangerous venomous animal:

1. Africanized Honey Bees. According to Cornett, bees cause more deaths than all the other animals combined.

Besides these animals, Cornett mentioned some snakes that are considered only mildly venomous, some of which are commonly kept as pets. None of these snakes have fangs, but the do have enlarged back teeth and toxic saliva. They need to chew on you for a while to work the venom in. These snakes include the ring-necked snake, black-headed snake, spotted night snake, lyre snake, hog-nosed snake, and the common garter snake.

Cornett related an incident with a hog-nosed snake. This snake was in an exhibit at the Palm Springs Desert Museum. Cornett was attempting to feed it a mouse, but since he handled the mouse, its scent got on Cornett’s hand. The snake bit him on the web between thumb and forefinger and chewed for a while before it could be detached. This mild venom caused swelling and discoloration of Cornett’s hand and arm and produced blisters for about a month. Nobody has antivenom for these snakes.

For more information on venomous animals, see:

Desert Bees and Africanized Bees

Scorpions, Vinegaroons, and Sun Spiders

Tarantula Hawks Deliver The Big Sting

Venomous Centipedes and Cyanide-Oozing Millipedes

Who’s Afraid of Tarantulas?

Rattlesnakes

Venomous Lizards

Desert Bees and Africanized Bees

Bee-in-saguaroMost bees are relatively harmless and beneficial, even vital for plant pollination, but the Africanized honey bees are dangerous and sometimes deadly. (See the story of the recent death of a Tucson man from massive bee stings here.)

Bees evolved from wasps. Bees are vegetarians that feed on nectar and pollen. Wasps are carnivores. In the Sonoran desert of Arizona, there are approximately 1,000 species of native bees. In the U.S. there are about 5,000 bee species.

According to the Arizona-Sonora Desert Museum:

Except for the parasitic cuckoo bees, all female bees make their living by foraging in search of protein-rich pollen and sugary nectar from flowering plants. By moving pollen around from flower to flower and plant to plant, bees perform vital and often unappreciated roles as the most important group of pollinating animals on earth. Yet bees are not out to “help” flowers; they collect pollen and nectar in order to feed themselves and their larvae.

Of the approximately 640 flowering plant taxa growing in the Tucson Mountains near the Desert Museum, approximately 80 percent of these species have flowers adapted for and pollinated by bees. Similarly, at least 30 percent of our agricultural crops require bees to move pollen between flowers. Not only are we dependent upon these “forgotten pollinators” for over a third of our food, but for other products as well. Cotton cloth is a product that eventually results from bee pollination, and so are many beverages and medicines made from other fruits and seeds.

Without the pollination services bees provide, many plants would not produce seed-laden fruits from which the next generation of plants would grow. Without bees, there would be few or no fleshy berries or fruits to sustain birds, mammals, and other wildlife. The tunneling activity of bees aerates the soil and allows water from infrequent rains to quickly penetrate and reach plant roots; and bees’ nitrogen-rich feces fertilize the soil. The bees themselves often provide food for lizards, mammals, birds, insects, spiders, and other arachnids.

In their daily quests bees harvest foodstuffs from flowers for themselves and their larvae. Pollen is a rich food source of amino acids, proteins, fatty acids, vitamins, minerals, and carbohydrates. Nectar provides the energy boost from sugars that bees need to fly. Some desert bees (Centris) have specialized scrapers on their legs for harvesting oils from glands on the undersides of specialized flowers in the ratany and malpighia families. These energy-rich oils are mixed with pollen as larval food and are also used to help construct brood cells. Other bees collect small pebbles, plant hairs, or floral resins that they use as building materials. Some bees, such as mason bees in the genus Osmia, also require water and mud with which to construct their adobe-like nests. Leafcutter bees (Megachile) remove circular pieces of leaves to fashion into cell walls. For more information, see the complete ASDM article here.

Most bees dig burrows in the ground, but some species use holes and tunnels made by other insects, especially beetles. The carpenter bees, those big black bees, may excavate there own holes in wood.

Most bees are solitary. Socialized bees in our region include the introduced honey bee, Africanized bees, and the native black and yellow bumblebees. For all bees, only the females sting. The stinger is an adaptation of the ovipositor, or egg laying structure. If the barbed stinger is left in the victim, the act usually rips the abdomen of the bee and causes it to die. There is some speculation that stingers evolved for inter-hive combat and in that case the bee did not lose the stinger.

Africanized Bees

A concise history of Africanized bees is available from DesertUSA:

Africanized Honey Bees (AHB) — also called Africanized bees or killer bees — are descendants of southern African bees imported in 1956 by Brazilian scientists attempting to breed a honey bee better adapted to the South American tropics.

When some of these bees escaped quarantine in 1957, they began breeding with local Brazilian honey bees, quickly multiplying and extended their range throughout South and Central America at a rate greater than 200 miles per year. In the past decade, AHB began invading North America.

Africanized bees acquired the name killer bees because they will viciously attack people and animals who unwittingly stray into their territory, often resulting in serious injury or death.

It is not necessary to disturb the hive itself to initiate an AHB attack. In fact, Africanized bees have been know to respond viciously to mundane occurrences, including noises or even vibrations from vehicles, equipment and pedestrians.

Though their venom is no more potent than native honey bees, Africanized bees attack in far greater numbers and pursue perceived enemies for greater distances. Once disturbed, colonies may remain agitated for 24 hours, attacking people and animals within a range of a quarter mile from the hive.

See the link above for the entire article.