Amber opens up unique insights into the past: the plants, animals and other organisms enclosed in the fossil tree sap remain almost unchanged over millions of years. Researchers have already discovered countless insects, poisonous prehistoric flowers, fungi and blood-sucking parasites in pieces of amber. Enclosed vertebrate fossils, such as the wing of a small primeval bird or the tail of a young dinosaur, are also very rarely found.
Amber finds often provide completely new insights: For example, George Poinar from Oregon State University has now discovered four previously unknown wasp species in lumps of amber from the Dominican Republic. He estimates their age to be around 20 to 30 million years. The new species are among the hunger wasps that are still alive today.
One of these hunger wasps can be seen in this photo – despite the old age, even the finest details of the insect are well preserved. Typically, these insects measure five to seven millimeters in length and can be easily recognized by their locomotion: their abdomen noticeably swings its wings back and forth with every movement.
And they have another special feature: hunger wasps lay their eggs on or in the eggs of cockroaches. When the wasp larva hatches, it will eat the cockroach egg. As it grows into an adult wasp, the larva feeds on about a dozen other cockroach eggs. Once a cockroach nest is infested with a wasp, not a single cockroach has a chance to survive.
“The wasps are sometimes referred to as the harbingers of the cockroaches – if you see hunger wasps, you know there are at least a few cockroaches around,” explains Poinar. “Some species of hunger wasps have even been used to control cockroaches in buildings.”
But did the wasps show this parasitic behavior millions of years ago? Although no cockroaches were included in the amber finds, the researcher discovered three flying termites in one of the pieces of amber. Poinar considers this discovery to be a very promising indicator, as the termites probably shared a nest with cockroaches and thus attracted the wasp. For the expert, this meant that wasps apparently fed their larvae the same way they did today 20 or 30 million years ago.