Everything’s Bigger in Texas, including the Occasional Spider Web

If creepy-crawly, eight-legged types are the stuff of your Halloween fears, you might want to stop reading here.

Rare events called "megawebs" have been known to happen in Texas after very heavy rains, not unlike what Austin has experienced in recent weeks. The temporary phenomenon involves hundreds of thousands of spiders living together in a giant spider web stretching across multiple trees.

The wet conditions bring a boom in the population of tiny insects that many spiders feast on. Emma Dietrich, a graduate student in ecology, evolution and behavior (EEB) at the University of Texas at Austin, studies spiders, and in 2016 she traveled to Arkansas Bend State Park to photograph a megaweb, after having previously photographed a similar event in 2015 near Dallas.

"Although this is the stuff of most peoples' nightmares, it is the stuff of an arachnologist's dreams," Dietrich wrote on her blog after seeing her first Texas megaweb up close. 

No megaweb has been spotted in 2018 – yet.

Researchers believe that when a megaweb happens, the different species of spiders tolerate each other's presence because food is plentiful. Small flies that swarm near water called midges abound after heavy rainfall, attracting the spider predators.

Texas megawebs occurred at Lake Tawakoni State Park in 2007 and in the Dallas suburb of Rowlett in 2015, and both were the work of thousands of long-jawed orb weavers (Tetragnatha guatemalensis). Other species of spiders tend to join the orb weavers. Among them, on the outskirts of these enormous communal webs, is the species that Dietrich studies, a spider called Anelosimus studiosus. 

Dietrich, who says she used to fear spiders before she came to understand them better, is working to understand the causes and consequences of social behavior in A. studiosus. In most places where the spider is found, adult females live alone, but in parts of the Southeastern United States, they cooperate in maintaining webs, capturing prey and caring for offspring. Earlier this month, Dietrich spoke about her research at Science Under the Stars, a monthly program organized by EEB graduate students and held at the Brackenridge Field Lab.

When she's not researching spiders or educating others about them, Dietrich and her fellow EEB graduate student Emlyn Resetarits host a podcast called STEM Fatale. They banter and talk a little about cool bug science, but mostly they cover what they've learned from researching outstanding women in science, technology, engineering, and math—both from history and currently. After launching in May, STEM Fatale already has more than 20 episodes, highlighting women such as physicist Jocelyn Bell Burnell, who discovered pulsars, and Margaret Collins, an entomologist and civil rights activist.

"Our goal of this podcast is to teach people about historical women in science in a friendly, low-key manner," Resetarits said.

Dietrich added, "It's science-y, but also involves some story-telling and us just being weird and having fun. It's also probably PG-13."

Photos and video courtesy: Emma Dietrich and Joe Lapp