ADHESION TO SMOOTH SURFACES BY INSECTS - A REVIEW

Several adhesion mechanisms have been proposed for insects adhering to and climbing smooth surfaces. In those species for which secretions between adhesive setae (specialized organs for adhesion on the footpads of some or all of the walking limbs) and the substratum are not detected the close contact between the setae and the substratum is thought to be indicative of molecular adhesion, arising from weak van der Waals' forces. In those insect species that produce secretions, identified as a light oil, actual measurements of the pulling forces needed to remove various insects from glass have shown that the surface tension of the light oil is sufficient to account for successful adhesion to smooth surfaces.