title: Attachment of Galerucella nymphaeae (Coleoptera, Chrysomelidae) to surfaces with different surface energy.
abstract: Numerous studies deal with insect attachment onto surfaces with different roughness; however, little is known about insect attachment onto surfaces that have different chemistry. In the present study, we describe the attachment structures of the water-lily leaf beetle Galerucella nymphaeae and test the hypothesis that the larval and adult stages generate the strongest attachment on surfaces with contact angles that are similar to those of leaves of their host plants. The larvae bear a smooth attachment system with arolium-like structures at their legs and a pygopodium at the abdomen tip. Adults have pointed setae on the ventral side of the two proximal tarsomeres and densely arranged spatula-shaped ones on their third tarsomere. In a centrifugal force tester, larvae and adults attained the highest friction forces and safety factors on surfaces with a water contact angle of 83 deg compared to those of 6, 26 and 109 deg. This comes close to the contact angle of their host plant Nuphar lutea (86 deg). The similarity in larval and adult performances might be a result of the similar chemical composition of their attachment fluid. We compare our findings with previous studies on the forces that insects generate on surfaces with different surface energies.
authors.affiliation: Department of Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany cgrohmann@zoologie.uni-kiel.de.
authors.forename: Constanze
authors.initials: C
authors.lastname: Grohmann
authors.affiliation: Department of Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Blankenstein
authors.affiliation: Department of Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Koops
authors.affiliation: Department of Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany.
authors.forename: Stanislav N
authors.initials: SN
authors.lastname: Gorb
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001517:Coleoptera / Q000033:anatomy & histology* / Q000648:ultrastructure; D005121:Extremities / Q000033:anatomy & histology; D005260:Female; D017276:Friction; D007814:Larva / Q000033:anatomy & histology / Q000648:ultrastructure; D008297:Male; D030721:Nymphaea; D018515:Plant Leaves; D013499:Surface Properties; D014867:Water
chemical_list: D014867:Water
keywords: Adhesion; Biomechanics; Contact angle; Friction; Insect; Locomotion