|
by Pat Flanagan
|
|
Tarantula Photo by Mark Heuston
click image to enlarge
|
|
Oh yes! Tarantulas cause more fuss when they are out and about than most any other spider or insect. You can’t be a big (3 - 4 inches) hairy predator with 8 legs and two beady black eyes without inciting reaction – pleasure and a smile of welcome from those familiar with these Hollywood branded terrorists or horror and fear from those in need of reassurance. The intention here is to reassure.
In the Mojave Desert these large bodied spiders are commonly seen in November when the males emerge and begin their migrations across the desert in search of receptive females. The males spend anywhere from three to ten plus years (sources vary on this) to reach sexual maturity. When ready, they grow a pair of claspers (look behind the knees on their first pair of legs) which are used to hold on to the female while copulating.
After copulation the male tarantula’s life is essentially over and he will survive for only a short time. As with other spiders, the female may devour the male to provide nourishment for the developing eggs. In his weakened state he also becomes easy prey for other predators.
The sedentary female tarantula has a life span of about 20 years becoming mature about 10 years of age. A female molts once a year which includes loosing the lining of the epigynum, the reproductive structure where the sperm are stored making mating essential before she can produce fertile eggs. After mating she lays her eggs in a burrow and may stay with them until they hatch. The young remain in the burrow until they are ready to disperse.
Given the outrageous examples of other arachnids, the life style of tarantulas, played out slowly over a number a years, is fairly tame.
|
|
|
Illustration by Callie Mack
|
Tarantula Diet
Tarantulas are among the hunters of the night: they feed on insects like grasshoppers, beetles, other small spiders, arthropods, and occasionally small lizards. Evidently size is a trigger for they will attempt to overcome anything the right size that moves in their range.
Diet of Tarantulas
Lizards, snakes, spider-eating birds, coyotes, and foxes are known to predate on tarantulas.
Tarantulas as Wasp Nurseries
The Tarantula Hawk, a large black wasp with orange wings, searches out tarantulas and attempts to sting them. If successful the sting paralyzes the tarantula and the wasp lays an egg on it before sealing it up in a burrow. The spider, held in suspended animation, provides the “fresh meat” for the wasp grub to eat after it hatches from the egg. The grub knows to avoid vital organs until the very end of its development.
Two More Things…
Since spiders have no teeth with which to chew their food they rely on their venom to liquefy their prey. They use their sucking stomachs to draw in or “suck” up a meal.
|
|
|
Illustration by Callie Mack
|
Tarantula venom is weak (bee sting strength) and they are gentle animals when respectfully approached and handled. They are, however, not passive and may react to aggressive or rapid movements. Do not pick them up by the back (aggressive) but allow them to walk onto your hand. Tarantulas use the specialized hairs on their abdomen which are barbed and irritating as defensive weapons when threatened.
There are many other interesting facts to learn about spiders but we hope this is enough to set your fears at ease so you can enjoy these fall beauties as they walk-about, propelled by familiar yearnings.
|
Ant society is a world of
females. Colonies are
dominated by the queen ant,
and she controls the
reproduction of her colony.
The queen starts life as a winged creature, and
along with winged male ants they leave an
established colony to start a new population. They
emerge from the nest, often in vast swarms, and
mate in midair. The females land, rip off their
wings, and begin digging to establish a colony. The
males simply die in heaps, after having lived a short
but let’s hope reproductive life. The queen then
stores the sperm in a special bag near the abdomen,
and uses this reproductive material for the rest of
her life. All eggs that she fertilizes become female,
and all the worker ants you see around an ant
colony are females. Males are created when eggs are
not fertilized, and only when they are needed to
start a new colony. It hardly seems fair. The queen
even chemically controls what kind of female ants -
queens, workers, soldiers - will be created. She is an
egg laying machine and it is the task of the rest of
the colony to help her maximize her reproduction.
One of the most common desert
ants are the harvesters. These
ants construct often enormous
craters, sometimes two feet or
more in diameter. They are cold blooded creatures,
emerging when temperatures go above 60 degrees
and move back underground when they top 111
degrees. Harvester ants feed on seeds, which they
gather in prodigious quantities. Workers from one
nest may gather 7,000 seeds a day. In one
experiment it was found that harvester ants found
considerable seeds from a plant species that hadn't
produced seed in over a year. They are hardy, and
readily attack other ants who intrude in their realm.
After a good summer rain, it is not uncommon to
find heaps of these ant’s wings from a sudden
massive spate of reproduction. 
