Tiny Beetles can be Tiger Moms, Too, Study Reveals

Female specimens of a subfamily of beetles native to tropical forests in Central and South America have been observed displaying explicit signs of maternal instincts and care, according to research published in a special edition of the journal Zookeys.

The researchers, from the Smithsonian Tropical Research Institute and several international universities, report that further study of the beetles' maternal trends could offer new perspective on the selective forces at work during the earliest stages of insect evolution.

Certain species of two colorful subfamilies -- the broad-shouldered leaf beetles (Chrysomelinae) and the tortoise beetles (Cassidinae) -- were observed corralling their larvae to food sources on leaves and keeping their offspring from straying too far away.

Other observations revealed that some species of the beetles would prepare for the birth of upcoming offspring by gathering or preparing food resources on the leaves where the birth took place and later, once the young were born, actively prevented the larvae from freely moving around on the plant.

Some species were observed taking defensive actions when researchers placed a foreign object such as a stick or a camera lens near a leaf where larvae were gathered. The mother beetles would charge to the edge of the leaf, stamping and shaking for a short time even after the foreign object was removed.

"Observations and field studies find evidence that mothers actively defend offspring in at least eight species and three genera of Neotropical Chrysomelinae tightly associated with two host plant families," the researchers wrote in a statement. "Reports on the three Doryphora species that feed on vines in the dogbane family, Apocyanaceae, reveal that mothers defend eggs and larvae by straddling, blocking access at the petiole and greeting potential predators with leaf-shaking and jerky advances. A less aggressive form of maternal care is found in two Platyphora and four Proseicela species associated with shrubs and small trees in the nightshade family Solanaceae."

Study author Donald M. Windsor, of the Smithsonian Institute, said that when it comes to our understanding the beetles, there are still a lot of unknowns.

"We urge continued study of these magnificent insects, their enemies and their defenses, both behavioral and chemical, especially in forests along the eastern versant of the Central and South American cordillera," Windsor said.