Scientist Theorizes How Cockroaches Survived Dino-Killing Asteroid Strike

We’ve all heard stories about cockroaches being able to survive just about any type of cataclysmic event (e.g., nuclear war). Well, Brian Lovett, a postdoctoral researcher at the Division of Plant and Soil Sciences at West Virginia University, wondered how they might have survived a dinosaur-killing asteroid strike.

Lovett penned his thoughts in the article “How did cockroaches survive the asteroid that led to the extinction of dinosaurs?” that appeared on Conversation.com.

“When the rock now known as the Chicxulub impactor plummeted from outer space and slammed into the Earth 66 million years ago, cockroaches were there. The impact caused a massive earthquake, and scientists think it also triggered volcanic eruptions thousands of miles from the impact site. Three-quarters of plants and animals on Earth died, including all dinosaurs, except for some species that were ancestors of today’s birds.”

Lovett said it’s possible cockroaches used their hiding skills and survival traits to endure. For example, as flat insects cockroaches can squeeze themselves into tight places. This enables them to hide practically anywhere — and it may have helped them survive the Chicxulub impact, he wrote.

Lovett also cited the fact that cockroaches are omnivorous scavengers, able to consume any organic food source available to them, and the fact that lay their eggs in little protective cases as helpful traits that allowed them to survive. — Source: Conversation.com

Lisa Taylor, a University of Florida entomologist, has spent her career studying arachnids. She says understanding how spiders think is just one of the unknowns that drives her research.

“They’re such tiny animals, with an even tinier brain, and a sensory system that we don’t quite understand,” she said.

This curiosity led Taylor and two international collaborators — Fiona Cross from the University of Canterbury in New Zealand and Robert Jackson from the International Centre of Insect Physiology and Ecology in Kenya — to examine the dietary preferences of an East African jumping spider known as Evarcha culicivora. Their findings are newly published in the journal “Animal Behaviour.”

“My collaborators spent years watching these spiders in the field and noticed that they were feeding almost exclusively on mosquitoes,” said Taylor, a research assistant scientist in the UF/IFAS entomology and nematology department. “This isn’t something that’s typical of all spiders — to specialize in one type of prey.”

Lisa Taylor, UF/IFAS

As they observed the spiders’ behavior, another trend emerged: The spiders seemed to be tracking the mosquitoes and targeting those with bright red abdomens, a tell-tale sign (to humans, at least) of a recently fed mosquito.

For the experiment, performed in Kenya, the researchers provided mosquitoes either red-dyed sugar water — which caused their abdomens to mimic a recent blood meal — or grey-dyed sugar water, to represent no-blood mosquitoes. The spiders strongly preferred the red-bellied mosquitoes.

“They didn’t have blood odor to rely on for their decisions, either,” Taylor said. “Using sugar water meant that smell was not a factor for the spiders to choose their prey.”

In the long run, Taylor said, such research can help with mosquito control. But in the short-term, she adds, it’s just another piece of the puzzle for spider research.

“This is a localized example, but it’s a good study system to help us understand how animals can make decisions with really tiny brains and a completely different sensory system than ours,” Taylor said. “It reveals broader patterns in the natural world.” Read the full study at bit.ly/3PJM3V9. — Source: UF/IFAS Entomology and Nematology Department