tom linder
.
Botany
Zoology
Microbiology
Immunology
Project study and Bachelor thesis
Trends in biological research
Common topics and tools
If ever someone wondered where "group sex" came from....:
Aggregations of Pyrrhocoris apterus
, known as Fire Bug or sometimes incorrectly referred to as Linden Bug or Red Soldier Bug,
in the street 'Nussallee' of the university campus in Bonn (June 2008).
The street 'Nussallee' is in greater parts lined by lime-trees (linden trees) which are known hosts to these bugs,
as the insects preferentially feed on the seeds of the linden trees.
In summer month the bugs come together and aggregate in many little heaps similar to the one shown here.
The Fire Bugs are known model insects and can be reared in laboratories.
According to a review by Socha (1993) aggregations of fire bugs are constituted by immature stages of the bug,
which is corroborated by the image above, as mostly nymph stages are visble (only one bug in the middle left seems to be fully developed).
The aggregations are guided by chemical and visual stimuli, but the exact purpose of such behaviour seems to be unknown.
Socha also states that these aggregations do not occur every year and not always at the same scale,
which is confirmed by my personal observations.
Research work of the Max-Planck-Institute for Chemical Ecology in Jena has revealed, that Pyrrhocoris apterus
,
as well as other species of the Pyrrhocoridae
family, harbor special communities of symbiotic bacteria in their mid-gut.
These bacterial communities consist mainly of members of the groups Actinobacteria, Firmicutes, α- and γ-Proteobacteria and
provide essential vitamins of the B group to their hosts, thus enabling them to digest the linden tree seeds,
which are deficient of B vitamins and contain the noxious, cyclopropenoic fatty acid malvalic acid.