Gravity orientation in social wasp comb cells (Vespinae) and the possible role of embedded minerals

Abstract

Social wasps and hornets maintain their nest in the dark. The building of the combs by all Vespinae is always in the direction of the gravitational force of Earth, and in each cell's ceiling, at least one 'keystone' is embedded and fastened by saliva. The sensory mechanisms that enable both building of sizeable symmetrical combs and nursing of the brood in the darkness merit investigation, and the aim of the present study was to identify and characterize the 'keystones' that exist in the ceiling and in the walls of the social wasp comb cells. Bio-ferrography was used to isolate magnetic particles on slides. These slides, as well as original cells, were analyzed in an environmental scanning electron microscope by a variety of analytical tools. It was found that both the roof and the walls of each comb cell bear minerals, like ferrites, as well as Ti and Zr. The latter two elements are less abundant in the soil around the nest. Ti and Zr are known to reflect infrared (IR) light. IR imaging showed a thermoregulatory center in the dorsal thorax of the adult Oriental hornet. It is not known yet whether these insects can sense IR light.

Magnetic isolation of particles suspended in synovial fluid for diagnostics of natural joint chondropathies

“…So far, BF has been used to track Escherichia coli bacteria at low concentrations in natural waters [28][29][30], characterize biofilms within ships' water ballast tanks [31], separate breast cancer and other cells from human peripheral blood [32,33], separate polyethylene wear debris from hip simulator fluid [34], capture of carbon nanoparticles produced by a pulsed arc submerged in ethanol [27] and determination of the role of magnetic minerals embedded in the comb cells of Vespinae [35].…”

Phylogeny of hornets: a total evidence approach (Hymenoptera, Vespidae, Vespinae, Vespa)

“…In the mid-19th century V. crabro was introduced into North America where it is now established (de Saussure 1898), while more recently, V. velutina was accidentally introduced into Europe, where it became invasive (Villemant et al 2011). Several hornet species have been the subject of various biological studies, either because of their social habits (Matsuura 1991, Foster et al 2000, Ishay et al 2008), their threat to human health (Vetter et al 1999), their impact on apiculture (Abrol 1994, Ranhabat et al 2009) or even their interest as edible insects (Ying et al 2010). However, the phylogeny of this genus is not yet well resolved.…”

Failure Analysis and Condition Monitoring of an Open-Loop Oil System Using Ferrography

“…This is a recent modification of the conventional ferrograph. It was specifically developed to allow for magnetic isolation of target cells or tissues [28][29][30][31][32][33]. These two types, however, are outside the scope of this article.…”