The world's original web masters make wonderful mothers, but deadly mates.
Spiders manage their own population and prey on insects that destroy vegetation. They offer natural pest control, provided they are protected from predators.
The 30th annual American Arachnological Society conference comes to Baltimore this week, giving more than 130 scientists from around the world an opportunity to share spider research, behavior and lore.
Nancy A. Kreiter, a Bel Air resident, has organized the conference on the campus of the College of Notre Dame of Maryland, where she is an associate professor of biology.
"If you care about an ecosystem that works, you have to care about all its parts, especially spiders," Kreiter said. "If you remove spiders, other insect populations will become overgrown and there will be plant damage."
Spiders are almost exclusively carnivores, predators that prey on plant-eating insects and mosquito larvae, Kreiter said.
"They do us a huge service considering what they are eating," she said. "If they are in your home, they are not in your flour or your clothes. They are eating your household pests."
Kreiter recalled her childish fear of spiders and her initial reluctance to take up arachnology at University of Maryland, Baltimore County where she earned a doctorate in biological sciences. After a year working as a neurobiologist, she decided she wanted a job that included outdoor research and returned to spiders.
"I actually was afraid of spiders when I was a little girl," she said. "Now I can look at them right in their eight eyes and study their behavior."
She has researched that behavior for the past 14 years, doing much of the research in the summer, when the creatures are most active. An expert in the field, she has handled hundreds of spiders with fangs and venom, but has never been bitten.
"Dr. Kreiter has such enthusiasm for her subject that everybody gets excited," said Virginia Weeks, a student research assistant. "They don't care that it's spiders because she makes it so interesting."
Kreiter fields calls from arachnophobes, helps neighbors identify critters and teaches children respect for spiders.
"I am 'Spiderwoman' to most kids," said Kreiter, who is married and the mother of two.
During the four-day conference, which opened yesterday, scientists will discuss everything from spider mating choices and maternal behavior to scorpion locomotion and web building.
"Spiders are a great organism to study," Kreiter said. "They are everywhere, important to ecology and easy to keep and work with."
Kreiter will share her latest research on her favorite of the species, known familiarly as fishing or nursery web spiders. Those are the brown, hairy creatures that inhabit the edges of ponds and occasionally invade a basement.
"Just put them back outside," she tells frantic callers.
She is keeping about 70 "teenage" female spiders in her lab at the college and will follow them through the mating cycle. They typically live two years, molting several times until they reach sexual maturity.
"Some are aggressive and chase at the male," she said. "Some are shy. We look at the big picture to see what influences their decisions."
Kreiter usually picks up males, who are the smaller and weaker of the species, at a pond. Male spiders approach the female with some trepidation, an entirely natural reaction, since they often figure into the female's food supply.
"Relationships between predators can be touchy," she said. "If a male doesn't approach a female, he will have no mate. If he does, he will probably get eaten. It's a terrible dilemma."
Though they may not be an ideal mate, "spiders are incredibly good mothers," she said. "Fishing spiders carry an egg sack in their mouths and hang the sack in vegetation, when it's about to hatch. Mom makes a nursery web for the babies and stays near."
She has recorded females with as many as 1,500 eggs in a single sack, although only a few survive.
"It is a dangerous world out there for baby spiders," she said.
Of course, there is no help from Dad, who is long gone, she said.
"The most energy for the offspring comes from the female," Kreiter said. "It illuminates questions about the male role."
A number of scientists study male-female relationships among spiders, comparing them with the conflicts common to humans.
"You have to be good natured and have a sense of humor when you work with spiders," she said. "We all research our own species and then come together at the conference to hear what we are doing. It offers us immediate feedback and collaboration. It really energizes research."
The conference will open to the public one-time only, at 7 p.m. tomorrow on the North Charles Street campus. The evening includes lectures, a video titled Scorpion Love, Base One and a recounting of the tale of tarantula hanky-panky.
"With spiders, courtship is mostly dance," Kreiter said. "Sometimes there is not even a handshake. But this will be even better than Discovery Channel."