September 24, 2004

Rayor Shares Spiders

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Not many people can link spiders with romance, but Prof. Linda Rayor, entomology, did just that when she met her husband while studying the creepy crawlers in graduate school. Now, Rayor hopes to communicate her love for spiders to others through her teaching, lectures and research.

In her Wednesday lecture, “A Romance With Spiders,” Rayor spoke in the Statler Auditorium about the basic biology of spiders while introducing common species found in homes and gardens.

Focusing a majority of her lecture on the incredible diversity of spiders, Rayor revealed that there are 38,000 spider species, more than all vertebrate species combined. Spiders are most abundant in the tropical rainforest area near the equator, but they are found on every land surface on Earth except for Antarctica.

Discussing spiders’ unique biological characteristics, Rayor specifically noted their external digestive system. Spiders kill their prey with their fangs and regurgitate digestive enzymes before sucking out the protein along with the exoskeleton, allowing them to molt and expand. She also spoke about the unusual spider reproductive system, in which males transfer their sperm to females through indirect fertilization. Rayor noted, however, that a serious sexual conflict exists between the two sexes, as males must first persuade females that they are potential mating partners and not prey. Because male spiders are often 1,000 times smaller than their female counterparts, “sexual cannibalism” may occur by females unaware that they are eating possible mates.

Introducing her audience to many spider species found in their own backyards, Rayor described the Orb Weavers (Araneidae) as “one of the first spiders I fell in love with.” She also described crab spiders, which can change colors to match a background of flowers. When attempting to identify a spider, Rayor said that one ought to focus on the presence and shape of the web, as well as the spider’s body shape, sturdiness of legs and eye pattern.

Rayor said that she became fascinated with these creepy crawlers while growing up in Denver where insects and spiders were rare because of the region’s dry climate. She recalled the excitement she felt as a child at seeing a praying mantis and fireflies for the first time.

Rayor later graduated from the University of Colorado-Boulder with a degree in biology, before earning her Ph.D. from the University of Kansas-Lawrence in 1987. As a graduate student studying prairie dogs, Rayor spent much of her time outside, where she became captivated by what she calls the “gorgeous and magical spiders.” Although Rayor’s scientific background was primarily in molecular biology, not animal science, she soon developed an interest in spiders.

Rayor teaches two classes at Cornell — ENTOM 215: Spider Biology: Life on a Silken Thread in the fall, and ENTOM 325: Insect Behavior every other spring. Besides teaching, Rayor spends most of her time conducting research on the relationship between spiders’ social interactions and their behavior as predators. Currently studying the “totally cool” Australian Huntsman spider, she said it is her favorite species because of its unique social habits.

Rayor is also the coordinator of the “Spider Outreach Program: Eight-legged Ambassadors of Science Education,” where she sends Cornell students into Ithaca classrooms to improve the reputation of spiders among schoolchildren. “Animal behavior is really accessible and appealing to non-scientists,” Rayor said. “Spiders are a great hook because they provide a combination of curiosity and horror.”

In particular, Rayor said that she would like to focus her energy on elementary school girls, who believe “it’s cooler to scream than to look at creepy crawlers.” Since the establishment of the program in 1998, the group has spoken to nearly 10,000 people. Thanks in part to her program, Rayor believes that “spiders have become very hip in the Ithaca metropolitan area, and arachnaphobia has been reduced.”

Theresa Dewey ’06, who attended the lecture for her Horticulture 480 class, said that she found the talk interesting even though she is not a big fan of spiders. “I didn’t realize there were so many species of spiders … it’s really bizarre,” she said.

Archived article by Olivia Oran
Sun Contributor