sciencetech-blog

comments

It is a tender moment frozen in time for at least 100 million years.

Scientists have uncovered the earliest fossilised evidence of an insect caring for its young.

The fossil shows a female sap-sucking scale insect, preserved in amber, carrying her freshly hatched nymphs and unhatched eggs on her abdomen.

The waxy ball like shapes on the abdomen of this 100 million year old insect Wathondra kotejai contain eggs and hatched nymphs and is thought to be the earliest example of parental care in insects yet discovered

The fossil, discovered in a mine in the Kachin Province of northern Myanmar, pushes back the earliest direct evidence for insects caring for their brood by more than 50 million years.

It is thought to be one of the earliest examples of parental care ever discovered and may help to explain how it first began to emerge.

Professor Bo Wang, a palaeontologist at the Chinese Academy of Sciences who led the research, said: 'Brood care could have been an important driver for the early radiation of scale insects, which occurred during the end of the Jurassic or earliest Cretaceous period during the Mesozoic era.

'Although analysis seemed to suggest that ancient insects evolved brood care, this is the first direct, unequivocal evidence for the fossil record.'

The insect Wathondra kotejai is thought to date from the mid-Cretaceous period and became encased in sap from a tree that over time turned into amber.

Around its abdomin are around 60 eggs and freshly hatched nymphs, encased within a wax-coated egg sack, according to the research, which is published in the journal eLife.

This primitive form of brood care would have protected the young nymphs from wet and dry conditions while allowing them to mature in the relative safety of their mother.

Fossilised evidence of animals caring for their young is extremely rare, especially in insects.

Wingless females were largely immobile, so were less likely to be accidentally buried.

A cockroach from a similar period was reported carrying a mass of eggs, but cockroaches often deposit their eggs rather than brooding them.

This drawing of a brooding female Wathondara kotejai shows the ovisac containing the brood and eggs coated in a wax covering as a lumpy mass on the main part of the insects body. Amber makes it almost transparent

Researchers believe Wathondara kotejai (above) may be one of the earliest insects to care for its young

Tiny hatched nymphs can be seen scattered aaround the mother insect's body in the amber in the image above

The only other direct evidence of brood care is from Cenozoic ambers, which are thought to only extend to around 65 million years ago.

The latest discovery is thought to be at least 100 million years ago and dates from a time when dinosaurs dominated the Earth.

The findings may help to offer an explanation for the early diversification of scale insects - small limpet-like suck saping insects that are common pests on plants today.

The emergence of flowing plants and ants are thought to have been crucial for the rapid evolution of many new inspect species but were not present when scale insects began to evolve.

Today many insects, such as ants and bees, care for their young, while the behaviour is far less common in mammals where just six per cent of species care for their young.

The insect was found encased in amber in a mine in the Kachin Province of northern Myanmar (shown above)

Wathondara kotejai is an ancient ancestor this sap-sucking scale insect that are now common garden pests