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08/14/2001
Daddy Longlegs Is Not a Spider
WARNING: This article may not be for the squeamish or faint
of heart. I had planned to start my column two days ago but a
rather impressive thunderstorm blew through our area and our
power was off for most of the afternoon. I didn''t realize what a
severe storm it was until today when we drove through the
neighborhoods just a mile or so away from our house. The
number of big trees down in that area was greater than in any
hurricane or ice storm I''ve seen in my nearly 50 years living in
New Jersey. Newspaper accounts described trees on power lines
exploding accompanied by what resembled Fourth of July
fireworks. The plus side to the storm was that it broke our 100-
degree heat wave. In trying to pick a subject for this week''s
column, with the heat and humidity, I knew it should be
something not too taxing for me or for you readers.
Then an incident occurred that decided the topic for me. I can
only describe the incident as being yucky and, well, gross! Some
years ago, studies showed that Listerine could help prevent
buildup of plaque on the teeth. I''m sure the makers of that
product were overjoyed by the finding; today, they are permitted
to call attention to this on their label and in their advertising.
Since reading of this report, I often swish Listerine around in my
mouth for 20 seconds or so and brush my teeth towards the end
of this period. Yesterday, following this practice, I brushed my
teeth and spit out the Listerine. It was somewhat of a shock to
see that along with the Listerine, I had spit out a sizeable
arachnid! Yuk! The spider, about 3/8 inch in diameter and a
yellowish color (possibly from the Listerine?) seemed just as
shocked as I was to have shared this Listerine experience. In this
era of reverence for life, I should probably have spared this poor
creature, but my response was to wash him down the sink as
quickly as possible.
Well, just a few days ago, I read an article about spiders by
Richard Conniff in the August 2001 issue of National
Geographic. At the time, I thought it might make an interesting
subject for a column but decided against it. Obviously, my
experience was an omen I couldn''t ignore. So, I reclaimed that
issue from our recycling pile and decided to look up some things
about these at times scary, but beneficial insects, in my Encarta
encyclopedia.
This has not been a good week, quite aside from the spider and
the heat. Sure enough, when I put the Encarta CD in the
computer, the computer told me that it wasn''t there! Undaunted
by the breakdown of my computer, I turned to our trusty old
1962 World Book. I come away from that experience totally
humbled and humiliated to find that I have forgotten what I must
have learned back in 10th grade biology class. For one thing, the
spider is not an insect! Hopefully, there are a few of you out
there who shared my ignorance of this fundamental fact.
Actually I carried out a scientific poll of three people. It revealed
that only one in three shared my ignorance.
I had known that the spider is an arachnid; at least I knew the
term. But an arachnid is not an insect. For one thing, an insect
typically has wings. At least at some stage of its life. In
retrospect, I don''t recall ever seeing a spider with wings.
Nevertheless, many, spiders are expert aviators. By playing out
their silken threads, they can form streamers that catch the wind
currents and you''re likely to encounter scads of them floating
around thousands of feet in the air at any given time. Their flight
paths can even cover hundreds of miles, permitting them to
colonize distant venues and spread their species. The
Geographic article mentions a study found that on a plot of a
couple acres, some 1800 spiders came drifting in like
parachutists every day.
What are some other differences between spiders and insects?
The spider has two segments to its body - its abdomen and its
thorax. Its head is part of its thorax, unlike an insect, which has
three segments, one of them its head. In a spider, the abdomen
houses its heart, intestines and even its breathing equipment. I
guess that''s why a spider''s abdomen usually is much bigger than
the rest of its body. A spider typically has 8 separate eyes.
Insects generally have just two eyes, each a compound eye
composed of many eyes.
The spider''s legs are all attached to the thorax. While an insect
has typically three pairs of legs, the spider has four pairs.
Speaking of legs, you''re all familiar with that brand of spider
known as daddy longlegs? Hopefully, some of you said yes.
Wrong! I was crushed to learn that daddy longlegs is not a
spider! Rather it is a cousin of a spider, both being distant
cousins of crustaceans like the crab. Although it is also an
arachnid, it is a Phalangida, whereas the spider is an Araneida.
My excuse for not knowing this is that my biology class was
roughly 60 years ago in Mechanicsburg, PA High School.
Back in Mechanicsburg as a kid, we often whiled away a
summer afternoon by tossing ants or other insects onto a spider''s
orbital web. Spiders seemed especially ferocious in those days.
It is well known that the spider''s silken threads are quite strong
for their size. The Geographic article states that a one-inch thick
rope of spider silk could hold up a load of 74 tons. This rope
would be three times stronger than the same size rope of iron.
With such great properties, you might wonder why we don''t see
more spider silks being used. After all, the silkworm''s output of
threads is highly prized and used to make those upscale items of
clothing. One reason is that spiders are cannibals. You''re
probably aware that a male spider runs a considerable risk when
dallying with his soulmate. She''s quite likely to turn around and
devour him! Not only that, but if you put a bunch of spiders in
the same space, these females would just as soon eat each other.
This makes it difficult to gather enough spider threads to make it
commercially attractive. Spider silk is used for the crosshairs in
some microscopes or other optical instruments.
When I was a kid, there was a well-known pitcher for the St.
Louis Cardinals by the name of Jay Hanna Dean, otherwise
known as "Dizzy". Dizzy Dean later became a baseball
broadcaster known for his fracturing of the English language.
"He slud into third base", for example. If he were alive, Dizzy
would no doubt be surprised to know that a species of spider is
named after him. The spider species, dizzydeani, has a taste for
male moths. It attracts the male moth by giving off a scent
similar to that of a female moth. Dizzydeani doesn''t make your
standard everyday orbital web. Instead, it makes the equivalent
of a spitball on a thread and beans a male moth with its spitball.
Then dizzydeani reels in the moth for consumption. I don''t know
if Dizzy the pitcher ever used the spitball or deliberately threw
beanballs at opposing batters. I do know he knocked down a
few.
The Geographic article also shows a picture of another untypical
approach to using the threads to capture an unwitting prey. The
Deinopis spider actually spins a very rudimentary net that it
holds with many of its eight legs. When an unsuspecting larva
moves into range, the spider swoops its net over it and snares the
larva. Just like a fisherman netting a fish!
"Fish or cut bait" could be the motto of many spiders that use the
conventional web to trap their prey. The spider has to very
quickly decide whether the particular creature is one that it can
handle when it approaches to administer the wrapping or the bite
that will paralyze its victim. If the spider decides that it''s
overmatched it may just cut away that part of the web and let its
victim drop out of the web.
A truly sinister story involves a couple particular species of wasp
and spider. This wasp stings the spider in the mouth, rendering
the spider unconscious, or at least unable to move. The wasp
then lays her eggs on the spider''s abdomen. The spider wakes up
and doesn''t realize what has transpired. It goes about its business
while the eggs hatch and the wasp larv'' start sucking the
spider''s blood. This goes on for maybe a week or two. You
probably think, "Well, that''s the end of the spider." You''re right,
but first the larv'' have to, as the author of the Geographic
article puts it, "take control of the spider''s mind." The spider
usually waits until the dawn of a new day to work on its orbital
web. But suddenly, during the night, the poor demented spider
starts going over and over the same spokes of its web. This
makes these spokes of the web quite sturdy. Just what those sly
larv'' want! After the spider has completed this task, it just sits
there, waiting to expire. The larvae have their last big meal and
drop the dead spider to the ground. Then they spin their cocoons
and hang themselves out to dry, so to speak. Where do they hang
themselves? On the sturdy spokes the demented spider just
finished!
Perhaps I should assure you that I have no connection with the
makers of Listerine. Also, you can be sure that I am now very
careful to inspect my cup and toothbrush for arachnids before
performing my plaque prevention procedure!
Allen F. Bortrum
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