Uncovering Insect Stickiness: Structure and Properties of Hairy Attachment Devices

Abstract

Interest in the mechanism used by insects for walking on smooth surfaces has a very long history. The very first reports, which described structures responsible for the adherence and provided ideas about possible mechanisms of attachment, are known from the 19th century. Different hypotheses, ranging from microsuckers to the action of electrostatic forces, have since been proposed. In 1862, Tuffen West mentioned that “the structure and action of the fly’s foot have been so frequently treated of, and are so generally considered to be fully understood, that it may appear, at the first glance, as if nothing further could be done with so hackneyed a subject” (West 1862). Some comparative accounts on hexapod pretarsal structures and a terminology were published later (De Meijere 1901, Holway 1935, Dashman 1953). To date, the morphological and ultrastructural bases of the ability of hexapods to walk on vertical surfaces have been studied in detail only in representatives of selected taxa, including Orthoptera, Thysanoptera, Heteroptera, Auchenorrhyncha, Dermaptera, Strepsiptera, Hymenoptera, Diptera, and Coleoptera.