Three tiny insects that lived about 90 million years ago have helped a North-West University (NWU) researcher uncover new clues about life on Earth during the age of the dinosaurs. The discovery also sheds light on how insects fed on plants and how some became the crop pests farmers face today.
Dr Sandiso Mnguni, a senior lecturer in agriculture at the NWU’s Potchefstroom Campus, has identified plant-feeding insects as fossils, which includes two new species of jumping plant lice and one aphid, found at Botswana’s Orapa Diamond Mine.
“The aphid is unique as it is the first complete fossil aphid from Africa, and it had an unusual mouthpart,” says Dr Mnguni, explaining that the insect has distinct body parts that helped him identify it.
The other two insects have unusual wing patterns that set them apart from previously known species of jumping plant lice.
The fossils were collected at the diamond mine during the 1980s and stored at the University of the Witwatersrand, where they remained available for further study.
Dr Mnguni began examining the collection in 2018 while studying towards his PhD. He had previously studied ancient beetles, but decided to explore other insect groups.
One of the discoveries (the first jumping plant lice) has special meaning for him. He named it Paternapsyllidium mckayi in honour of his late PhD supervisor, Dr Ian McKay, who trained him in the study of ancient insects.
The second jumping plant lice, Derivatupsyllidium kimperlitis, takes its name from kimberlite, a type of rock linked to diamond deposits. The name reflects the fossils’ origin at Botswana’s Orapa Diamond Mine.
Dr Mnguni explains that a volcanic eruption triggered by volatile gases like carbon dioxide, steam and mineral-rich fluids from the kimberlite resulted in a crater lake in the centre and helped form the rock deposits at the mine.
The third insect, an aphid named Oviparosiphum adamas, takes its name from the Latin word for diamond. The name reflects the diamond mining operation where the fossils were discovered.
Discovery offers clues about ancient life
Dr Mnguni says the findings help scientists understand how insects lived and survived millions of years ago. The work contributes towards a more accurate documentation of diversity and enables us to map their distribution at the time.
During that period, flowering plants became more common, which changed the environment and created new food sources for insects. Like their modern relatives, these ancient insects fed on plant sap. Today, similar insects damage crops, spread plant diseases and affect food production.
“The descriptions provide further insight into the insect diversity of the Orapa Diamond Mine during the Cretaceous period, a time between 145 million and 66 million years ago when dinosaurs roamed the earth,” says Dr Mnguni.
He worked with researchers from the Agricultural Research Council, Citrus Research International and the University of Fort Hare due to their expertise on working with modern relatives of the ancient insects.
Dr Mnguni plans to continue studying the fossils to understand how these insects are related to other species.
His work will help scientists build a clearer picture of ancient life and how insects have changed over millions of years. The work will also help crop farmers to understand how the insect pests have evolved over the years.
The work shares insights into plant-insect relationships. The knowledge can support the development of more effective and sustainable crop protection and integrated pest management strategies in the future.
Dr Sandiso Mnguni
New species of jumping plant lice: Paternapsyllidium mckayi
New species of jumping plant lice: Derivatupsyllidium kimperlitis.
The third insect, an aphid named Oviparosiphum adamas, takes its name from the Latin word for diamond.
The Orapa Diamond Mine
