Chemical Composition of Footprints and Cuticula Lipids of Three Species of Lady Beetles.

Abstract

Lady beetle can walk on a vertically smooth surface such as a glass plate in the same manner as on a horizontal one. It was reported that the insect probably released a non-volatile lipid secretion from the spatulate ends of the tenent hairs and this secretion was essential to the adhesion process on smooth surfaces against the force of gravity. We have studied footprint chemicals which were secreted from the tenent hairs of the three species of lady beetles Epilachna vigintiocotomaculta, Epilachna vigintioctopunctata and Coccinella septempunctata. The component of footprints was species specific and consisted of hydrocarbons and true waxes. The footprint chemicals were just identical with those of the cuticular waxes. The waxes of footprints were secreted larger amount from the tarsus than that from cuticular surface.

Role of long-chain hydrocarbons in the aggregation behaviour of Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae)

“…They could then be used by the ladybirds to evaluate the age of deposits, giving them information about the recentness of conspecific activity and thus about the suitability of a microsite. Kosaki and Yamaoka (1996) highlighted the presence of hydrocarbons in ladybirds footprints and suggested their involvement in the adhesion of these insects on smooth surfaces. It follows that Table 2 Results of the aggregation assays involving microsite extracts naturally laid by ladybirds on one hand and artificially deposited by experimenter on the other hand.…”

“…The blend may change to some extent over time but it contains certain very stable components, notably saturated hydrocarbons (Jamart et al, 2009), which could be used by the first individuals to orientate towards the microsite. Since area marks probably originates from footprints laid passively (Kosaki and Yamaoka, 1996), these first individuals would refresh and reinforce the marking while walking around the microsite. This could then facilitate the orientation of the later individuals and beetles the following year.…”

“…It is known that ladybirds leave hydrocarbon tracks as they walk (e.g. Kosaki and Yamaoka, 1996): we therefore also analysed chemicals left by overwintering H. axyridis while walking. To do so, 40 ladybirds from infested houses were introduced into a glass Petri dish previously cleaned with norvanol (ether-denatured ethanol, 93% purity -VWR International, Haasrode, Belgium) and were allowed to mark it by walking for a period of 24 h. These Petri dishes were kept at 22 ± 1°C, so we obtained only small aggregations over the 24 h. After this length of time, ladybirds were picked up and the marking was collected with quartz wool impregnated with nhexane.…”

Attachment force of the beetle Cryptolaemus montrouzieri (Coleoptera, Coccinellidae) on leaflet surfaces of mutants of the pea Pisum sativum (Fabaceae) with regular and reduced wax coverage

“…Crystals of different length and different crystal densities did not strongly affect the surface wettability, but significantly influenced insect attachment. This means that the surface roughness affects the force reduction not necessarily through the wettability reduction, especially if we take into account purely lipide-like nature of a beetle pad secretion (Ishii 1987;Kosaki and Yamaoka 1996;Eisner and Aneshansley 2000). It is clear that here we deal with a complex contact mechanics phenomenon and observe an integration of overlaying effects of various parameters, but data obtained let us assume that the attachment force depends primarily on the surface profile and ability of insects to establish real contact with the substrate and secondarily on the surface wettability.…”

Biological attachment devices: exploring nature's diversity for biomimetics

“…Insects, spiders and some lizards (geckos and skinks) bear attachment devices of either hairy (figure 2e) or smooth type (figure 2g), which provide proper contact formation with almost any kind of smooth natural substrates and by this generate strong friction and adhesion (Hiller 1968;Irschick et al 1996;Autumn et al 2000;Gorb et al 2002;Gao et al 2005;Huber et al 2005;Bhushan et al 2006;Tian et al 2006;Kim & Bhushan 2007). Some of these attachment pads are supplemented with various kinds of fluids (wet adhesion ;Ishii 1987;Kosaki & Yamaoka 1996;Attygalle et al 2000;Federle et al 2002;Vötsch et al 2002) and some are not (dry adhesion ;Homann 1957;Autumn et al 2000;Autumn & Peattie 2002;Huber et al 2005). Most of the locomotory systems also bear stiff-pointed hairs and/or claws (figure 2f ), which provide mechanical interlocking on substrates with either strongly corrugated profiles, compliant surfaces or substrates consisting of threads or fibres (spider orb webs and plant trichomes; Gorb & Barth 1994;Dai et al 2002;Voigt et al 2007).…”