Tuesday 8 April 2014

3rd April 2014 - Mud-puddling Seraphim

A small group of geometrid moths were found flitting around a shallow rut in this forest trackway and on closer examination some of them were seen working their proboscides on the damp soil surface. They were Lobophora halterata (The Seraphim or Szárnyfüggelékes Araszoló). A brief shower during what had been until then a very dry early spring had resulted in a small puddle forming on the trackway. Whereas elsewhere on the forest floor the water quickly disappeared through soil percolation and evapotranspiration, in the shady rut the moisture was slightly more long lived. 

Lobophora halterata
Mud-puddling - the intake of moisture from damp mud by adult Lepidoptera - is often associated with butterflies and can result in spectacular congregations of insects (see here  for a great 3 minute film about this from Thailand by www.earthtouchnews.com) but many moths have also been observed in this habit. The insects are usually males. In a field study in Pennsylvania by Adler (1982), in which more than 3000 individuals from 10 families of the Lepidoptera were seen visiting puddles, 99% were males. It is thought that this behaviour developed naturally from water drinking. The incidental intake of dissolved sodium ions (and perhaps other nutrients) may have given some reproductive advantage to the insects which has in turn led to the evolution of a behavioural habit which is very strong in some species (but not recorded in others - the biological and nutritional function of mud-puddling is still incompletely understood).

Lobophora halterata