Sibling cooperation boosts survival in beetle larvae, even without parental care

Researchers from the University of Bayreuth have discovered that the off -center of the coéoptera’s burial benefited from his brothers and sisters – that their parents are present to provide care. This calls into question the long -standing paradigm that the rivalry of the brothers and sisters on parental resources prevails over all the advantages, which makes the brothers and sisters a drawback for individual offspring.

The results are published in the journal The American naturalist.

Whether in insects or humans, social relations play a vital role in the lives of many animal groups, family life being particularly important. Although family life has evolved independently on several occasions in different groups of animals, social interactions often have similarities: parents interact with each other and with their offspring, and offspring interact with each other.

Research on the effects of social isolation – such as the absence of parents – has traditionally focused on primates or rodents. However, these animals cannot generally survive without parental care, limiting ideas that such studies can offer the effects of social isolation.

Studies like that carried out in Bayreuth, which examine social interactions in other species, help explore the evolution of family life and generate hypotheses on how family structures can develop in other animals, including humans.

For a long time, the interactions between parents and their offspring were considered to be the main evolutionary engine of family life in the animal kingdom. However, recent studies between various species suggest that other forms of interaction also play a crucial role in the development of social behavior.

“There are still important shortcomings in our understanding of how interactions on brothers and sisters work in parallel with parent-offspring interactions, and what happens when contact between brother or sister is absent in different forms of parental care, in particular how the interactions on the brothers and sisters are influenced by the presence of parents on the part of the Parents of Bayreuth and the study.

“A more in -depth understanding of these aspects could be key not only to grasp the evolution of family life, but also to expand our knowledge on the development of highly social species, including humans,” adds Professor Sandra Steiger, president of evolutionary animal ecology at the University of Bayreuth.

To fill these knowledge gaps, Bayreuth researchers studied the parental care behavior of the buried scarab Nicrophorus Vespiloides. In this species, the mother and the father generally take care of the larvae by preparing the carcass in which the offspring is increased and nourishing them after their hatching. However, the larvae can survive even in the absence of one or two parents.

The ability to benefit from parental care without being dependent on it makes Nicrophorus Vespiloides an ideal model organism to study the role of isolation of family members in animals.

In their experience, researchers raised larvae alone or with brothers and sisters. The larvae were randomly assigned to different test groups: parental care by both parents on a prepared carcass; No parental care but a prepared carcass; No parental care and unpaid carcass. In a second experience, individual larvae or groups of brothers and sisters were treated for both parents or by one.

“Our study shows that the larvae benefit from the presence of brothers and sisters both when the parents are present and when they are absent. This is surprising, as it was supposed before that even if the brothers and sisters can cooperate in the absence of parents, they compete for attention and resources when parents are present,” said Huber.

Researchers suspect that begging behavior shared among larvae can reduce the effort required by individual while increasing global parental investment in the brood.

The study was carried out within the framework of the project “The effect of social isolation on the performance of offspring: an evolutionary, ecological and molecular perspective”. Since 2023 to 2026, the project aims to deepen our understanding of the effects of social isolation on several levels.