Potter wasp nests in Cretaceous amber.

Area of Science:

• Paleoentomology
• Insect Evolution
• Behavioral Ecology

Background:

• Nesting is a key insect adaptation for reproduction and resource management.
• Potter wasps (Eumeninae) exhibit complex solitary nesting behaviors, but their evolutionary history is unclear due to limited fossil evidence.

Purpose of the Study:

• To investigate the evolutionary origins of potter wasp nesting behaviors.
• To provide the first direct fossil evidence of Eumeninae nesting.

Main Methods:

• Discovery and analysis of fossilized potter wasp nests preserved in mid-Cretaceous Kachin amber (approximately 99 million years old).
• Morphological comparison of fossil nests with extant Eumenini species.

Main Results:

• The discovery of fossilized potter wasp nests in mid-Cretaceous amber.
• Fossil nests show morphological similarities to extant Eumenini nests, including bottle-shaped architecture and mud construction.
• Preserved eggs were found within the fossil nests.

Conclusions:

• Potter wasp nesting behaviors, including mud nest construction and brood care, were established by the Cenomanian stage of the Cretaceous period.
• This finding significantly pushes back the known evolutionary timeline for these complex behaviors.
• The fossil evidence provides crucial insights into the early evolution of social and nesting strategies in Hymenoptera.