Jump to content

[Animals] Can woolly caterpillars really predict what winter will be like?


Recommended Posts

Posted

As the seasons change and the world gets colder, most of Spain's caterpillars will have already transformed into adults. But not woolly bear caterpillars or woolly caterpillars (Pyrrharctia isabella): these fascinating creatures, also called woolly caterpillars, are one of the few that hunker down and face winter in the larval state.

Although many people probably don't know how to identify the larvae of many other moth species, woolly caterpillars are relatively well known. And not only because they are very visible in the fall, when they can be seen crawling along sidewalks and roads in cold climates (especially the United States and Canada) at an impressive speed, at least for a caterpillar.

Since colonial times, woolly caterpillars are said to be able to predict the weather: their markings suggest a harsher or milder winter.

There are all kinds of variations on this main theme, but what you really need to know is that they are all false.

"I hate to be a spoilsport, but there's never been a really clear set of data that says, 'Yes, this is absolutely true,'" says Katie Marshall, a comparative physiologist at the University of British Columbia in Canada who studies how animals adapt. to the cold.

However, woolly bear caterpillars have a very real winter superpower: freezing.

Why caterpillars don't predict winter

 

3QiSkEM.png


Although there are hundreds of woolly-looking species in the Erebidae family, the most common and recognized woolly bear caterpillar is Pyrrharctia isabella, or the larval form of the Isabella tiger moth, Marshall says.

According to legend, the more black mushrooms (long spiny hairs) a woolly toadstool has, the harsher the coming winter will be. Likewise, larger bands of red or brown in the central part of the caterpillar predict a warmer, milder winter.

Some scientists have studied all of this and found no relationship between the patterns of the woolly caterpillar's quills and the severity of the weather ahead, although Marshall cautions that most of this work has been more tongue-in-cheek than serious.

But the colors of woolly bear caterpillars may indicate other things. For example, these caterpillars tend to shed their exoskeleton six times before transforming into moths, a process known as molting. And each time they do so, they become more rusty and less black in color. This means that the youngest caterpillars are usually black, while the most colorful ones are usually the old and withered ones in a given po[CENSORED]tion.

What's more, there are some connections between the appearance of a woolly caterpillar and the climate. Marshall says color patterns could indicate how early or late a caterpillar last molted, which could reflect trends in time and temperature. Likewise, caterpillars with blacker coloration would theoretically absorb more sunlight.

 

https://www.nationalgeographic.es/ciencia/2023/11/orugas-lanudas-prediccion-como-sera-invierno-leyenda-urbana-realidad

Guest
This topic is now closed to further replies.
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.