Scientists say it's the first time a fossil from a large butterfly species has been discovered preserved inside an ancient block of amber. They've described it as an "exceptional" find.
The critter is the first caterpillar of its kind to be discovered in Baltic amber, according to researchers from the Bavarian State Collection of Zoology in Munich.
The 5-millimeter (0.2-inch) larva has been given the name Eogeometer vadens under the family of Geometridae butterflies, which comprises around 23,000 different species.
Scientists said the little caterpillar likely got trapped in a drop of tree resin, which ultimately hardened into amber and preserved the worm's unique structure over millions of years.
"Caterpillar finds in amber are rarities in any instance, and this is the first ever large butterfly fossil to be found in Baltic amber," study co-auther Axel Hausmann said. "This may be due to the noctural activity of most caterpillars," he added, given that resin would likely be closer to liquid in direct sunlight or warmer daytime temperatures.
Unlike most other butterfly species, Geometridae caterpillars only have two or three pairs of legs instead of the usual five pairs. This means they move forwards with an unusual gait — by pushing their hind legs to their rear legs, then stretching out and repeating the action.
The researchers said the fossil would provide an insight into evolutionary processes during the Eocene period (about 34-56 million years ago), when flowering plants butterfly species would have been interacting with were already well established.
The Autumn armyworms: Dangerous caterpillars
The autumn worm isn't really a worm, but a caterpillar. When it's fed enough it turns into a moth which can cause catastrophic damage to crops in southern and eastern Africa.
Image: Lyle J. Buss/University of Florida/Bugwood.org
The autumn worm
The small caterpillar - no bigger than four centimeters - is not as harmless as it looks here. When thousands of these small pests fall into a field, the harvest is quickly destroyed. The wandering pests gnaw across the whole country.
Image: picture-alliance /dpa/CABI
The enormous corn eater
Spodoptera frugiperda (that is the name of the army worm in Latin) likes corn. He eats the leaves, but above all he bites through the inside of the plant. Corn is the most important nutrient supplier, especially in the south of the African continent. The FAO estimates that the pest can destroy more than three-quarters of a crop.
Image: Phil Sloderbeck/Kansas State University/Bugwood.org
Attack! Eat with military strategy
These spot-camouflage caterpillars crawl from field to field as if they're marching in to battle - that's why they are called "armyworms." In huge numbers they march from grasslands on to crops, where they eat everything in sight.
Image: gemeinfrei
Growing up in stages
On their way to adulthood, the seemingly never-ending caterpillars pass through six stages: from the tiny, transparent larvae to the almost four centimeters long moths. If they grow up, they pupate - the process of becoming a moth - just under the surface of the ground.
Image: Natalie Hummel/Louisiana State University AgCenter/Bugwood.org
From caterpillar to moth
After three weeks of feasting on crops and grass, the transformation begins. Then we see the metamorphosis to the "Noctuidae" - an owl-like butterfly.
Image: Mark Dreiling/Bugwood.org
Wings up and read to go!
And this is how the creature looks in all its splendor. With a wingspan of just under four centimeters, the nocturnal moths provide fast and efficient offspring - with females laying up to 1000 eggs in their lifetime. With no frost in the African climate you could find up to 12 generations in just a single year.
Image: Lyle J. Buss/University of Florida/Bugwood.org
Problems across Africa
Small, light and greedy: The moths can spread quickly over hundreds of kilometers in favorable winds throughout the continent. At the beginning of 2016, the Autumn armyworm was first detected in Nigeria, a year later it was already flying about 5000 kilometers further south. Europe is by no means too far away, experts warn.
On a journey around the world
The United Nations is already warning of a new crawler plague across Africa. "Pests do not know any national borders," says the UN Organization for Food and Agriculture (FAO). Originally, the butterfly species originates from the tropical regions of the American continent. From there they were towed to Africa.
Image: CC by Andy Reago & Chrissy McClarren
Limited solutions
Resistant Plants, Sand, or Chemistry: Farmers in North and South America have tested many compounds against creeping armyworms. It is best to fight the pest with pesticides, but some have already shown resistances. Experts suggest to dig trenches around the affected field. That way the caterpillars can be easily killed when they try to reach the neighboring field.