South Indian Leaf Beetles Live in Holes Made By Other Species, StudyBy Staff Reporter
'Orthaltica Eugenia and Orthaltica Terminalia,' the two recently discovered species of leaf beetles alter holes created by other beetles and use it as a shelter, according to a new study conducted by researchers from the Department of Entomology, Kerala Agricultural University, India.
The two southern Indian related species are just the size of a pin head. The beetle measures about 1.20 - 1.50 mm long and 0.75 - 0.84 mm wide. As a result, they are able to fit into leaf holes made by larger munching beetles.
"The beetles are named after their host trees, common in jungles of the Western Ghats Mountains, which is a globally recognized hot spot of biodiversity," the press release reported.
Builders among the adult leaf beetles are uncommon. But young ones of certain species use their own feces to build defensive guards.
"Leaf-hole shelters provide a roosting site that offers a certain degree of camouflage as well as protection. In the field it was observed that on sensing the presence of an enemy on one side of the leaf the occupant of a leaf-hole shelter could easily shift to the other side, making itself invisible to the intruder. It may also be presumed that larger predators cannot pass through the hole in pursuit of the occupant," the study reported.
These two closely related species have been found to use already existing holes to construct hideouts called 'leaf hole shelters.' If the holes did not match the requirements of the beetles, they would then adjust them using their own fecal pellets. This is the first time researchers have discovered an adult leaf beetle using its own feces for constructing shelters.
"In the case of the triangular artificial leaf-holes, beetles had a distinct preference for the narrow vertex of the triangle, above its wider base. This may be because their size allowed them to easily fit inside the narrow apical angle," says the study, titled "First record of leaf-hole shelters used and modified by leaf beetles (Coleoptera, Chrysomelidae), with descriptions of two new Orthaltica Crotch species from southern India," according to the press release.