The first cockroach to feed on lizard tears
On the night of March 29, 2019, the photographer Javier Aznar González de Rueda observed a thin anole (Anolis fuscoauratus) sleeping on a branch in the Ecuadorian Amazon. Above its head, a cockroach remained motionless with its mouth in the corner of the reptile’s eye, a scene that was immortalized in a photograph. After several minutes, the insect moved away and the lizard slightly opened its eyes without flinching.
These insects visit their predators at night to find such food sources, which could be triggered due to high competition in tropical rainforests.
Matthijs P. van den Burg
What was the cockroach doing? The insect was feeding on the anole’s tears, a behavior known as lacrifagia, and that in general they practice animals with proboscis (an elongated and tubular appendage located on the head of certain insects) such as moths and butterflies, and even bees, to supplement their diet of salts and other nutrients through the secretions of turtles, crocodiles, lizards or birds.
Thanks to the image that the photographer published on social networks, the scientist Matthijs P. van den Burg, from the National Museum of Natural Sciences of Madrid (MNCN-CSIC), got in touch with him and together they began to describe in a new study the first observation of feeding based on tears by cockroaches, a group of insects very abundant and common.
Belonging to the blasting, more than 4,500 species of cockroaches of 500 genera are known. But despite their high number and being common even in homes, we still have a lot to know about these flattened-bodied, reddish-brown insects.
The results, published in the journal Neotropical Biodiversity, reveal that cockroaches have a broader diet than previously believed. “These insects visit their predators at night to find these food sources, which could be triggered by the high competition in tropical forests,” van den Burg explains to SINC.
Day and night to drink tears
Although until now it was thought that all lacrimal species only sucked tears thanks to their long proboscis, called espiritrope in the case of butterflies, species that lack this organ can also do so. However, they could risk damage or being eaten since, like the roach with the thin anole, they are in close proximity to the host.
This behavior has surprised the researcher since until now it was thought that lacryphagia was a diurnal behavior
To reduce the risk of predation, these blatodeans feed on secretions at night, although some diurnal reptiles are more active in the dark. This behavior has surprised the researcher since, until now, lacryphagia was thought to be a diurnal behavior.
“Our work provides new knowledge about the natural history of cockroaches,” says the expert, from the Department of Biogeography and Global Change at the MNCN. This behavior could also harm reptiles if viruses or bacteria are transferred during the interaction.
For the biologist, the discovery of the lacryphagia of cockroaches on lizards, a phenomenon very difficult to observe, allows a better understanding of the interactions between species throughout the world. “We lack this information for most of the described species,” concludes van den Burg.
Matthijs P. van den Burg & Javier Aznar González de Rueda. “Lachryphagy by cockroaches: reptile tears to increase reproductive output?” Neotropical Biodiversity
Rights: Creative Commons.