Dr. Martin Kaltenpoth
Department for Zoology
University of Regensburg
My research interests lie in evolutionary and behavioral ecology, especially the evolution and ecological significance of symbioses between insects and bacteria. In my PhD project, I worked on European beewolves (Philanthus triangulum, Hymenoptera, Crabronidae), which are solitary digger wasps that build nests in sandy soil and provision their larvae with paralyzed honeybees in the underground nest cells.
Beewolves harbor endosymbiotic bacteria of the genus Streptomyces in specialized antennal glands. The bacteria are applied to the brood cell and taken up by the larva. The larva applies the bacteria to the cocoon silk when spinning the cocoon, so the Streptomycetes are present in large numbers on the cocoon. They protect the cocoon from fungal infestation, thereby greatly enhancing larval survival. I am currently focusing on the following questions:
(1) In which species do the antennal bacteria occur?
(2) How old is the beewolf-Streptomyces symbiosis, and have beewolves and their symbionts coevolved?
(3) How do the bacteria get from the larva into the antennal glands of the adult beewolf?
(4) How do the bacteria protect the cocoons from fungal infestations? What kind of secondary metabolites from the bacteria might be involved?
(5) Does the genome of the bacteria reflect their endosymbiotic lifestyle? What are the metabolic abilities of the symbionts, and what kind of nutrients may have to be provided by the beewolf host?
As a second model organism, I am working with red soldier bugs (Pyrrhocoris apterus, Heteroptera, Pyrrhocoridae) that harbor symbiotic bacteria in their digestive tract. I am interested in the mode of transmission of the symbionts from one generation to the next and the fitness effects of the bacteria for the hosts. Additionally, I would like to address questions concerning the specificity and intimacy of symbiotic associations between insects and bacteria in this model system.
Furthermore, I am interested in the chemical communication in insects, specifically the male marking pheromone of European beewolves, and its possible significance for sexual selection and female choice.
Grants and fellowships
Roeser-Mueller K, Strohm E, Kaltenpoth M (2010). Larval rearing temperature influences amount and composition of the marking pheromone of the male beewolf (Philanthus triangulum). Journal of Insect Science 10:74, available online: insectscience.org/10.74
Kaltenpoth, M., Goettler, W., Koehler, S. & Strohm, E. (in press) Life cycle and population dynamics of a protective insect symbiont reveal severe bottlenecks during vertical transmission. Evolutionary Ecology, DOI 10.1007/s10682-009-9319-z.
Kaltenpoth, M., Schmitt, T. & Strohm, E. (in press) Hydrocarbons in the antennal gland secretion of female European beewolves, Philanthus triangulum (Hymenoptera: Crabronidae). Chemoecology, DOI 10.1007/s00049-009-0022-x.
Strohm E, Herzner G, Kaltenpoth M, Boland W, Schreier P, Geiselhardt S, Peschke K, Schmitt T (2008). The chemistry of the postpharyngeal gland of female European beewolves (Hymenoptera: Crabronidae). Journal of Chemical Ecology 34: 575-583.
Kaltenpoth, M. & Strohm, E. (2007) Life within insect antennae: Symbiotic bacteria protect wasp larvae against fungal infestation. Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology 146 (4): S66-S67.
Kaltenpoth M, Kroiss J, Strohm E (2007) The odor of origin: kinship and geographical distance are reflected in the marking pheromone of male beewolves (Philanthus triangulum F., Hymenoptera, Crabronidae). BMC Ecology 7:11.
Goettler, W., Kaltenpoth, M., Herzner, G., Strohm, E. (2007) Morphology and ultrastructure of a bacteria cultivation organ: The antennal glands of female European beewolves, Philanthus triangulum (Hymenoptera, Crabronidae). Arthropod Structure and Development 36: 1-9.
Kaltenpoth, M. (2006) Protective bacteria and attractive pheromones - symbiosis and chemical communication in beewolves (Philanthus spp., Hymenoptera: Crabronidae). PhD thesis, University of Wuerzburg.
Kaltenpoth, M. (2006) Symbiotische Streptomyces-Bakterien in Grabwespen. Naturwissenschaftliche Rundschau 59 (11): 618-619.
Kaltenpoth, M., Strohm, E. (2006). The scent of senescence: Age-dependent changes in the composition of the marking pheromone of the male European beewolf (Philanthus triangulum, Hymenoptera, Crabronidae). Journal of Insect Science 6:20.
Kaltenpoth, M., Göttler, W., Dale, C., Stubblefield, J.W., Herzner, G., Roeser-Mueller, K., and Strohm, E. (2006) 'Candidatus Streptomyces philanthi', an endosymbiotic streptomycete in the antennae of Philanthus digger wasps. International Journal of Systematic and Evolutionary Microbiology 56 (6): 1403-1411.
Kaltenpoth, M. (2005). Life history and morphometry of the Chinese praying mantis, Tenodera aridifolia sinensis (Blattopteroidea: Mantodea). Entomologia Generalis 28 (1): 1-16.
Kaltenpoth, M. (2005). Bakterien schützen Wespen-Nachwuchs vor Pilzbefall. Naturwissenschaftliche Rundschau 58: 329-330.
Kaltenpoth, M., Göttler, W., Herzner, G. and Strohm, E. (2005). Symbiotic bacteria protect wasp larvae from fungal infestation. Current Biology 15: 475-479.
Kaltenpoth, M., Strohm, E. and Gadau, J. (2004). Polymorphic microsatellite markers for a solitary digger wasp, the European beewolf (Philanthus triangulum; Hymenoptera, Sphecidae). Molecular Ecology Notes 4: 589-592.