Resource availability as a proxy for terminal investment in a beetle

Indrikis A. Krams, Tatjana Krama, Fhionna R. Moore, Markus J. Rantala, Raivo Mänd, Pranas Mierauskas, Marika Mänd

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13 Citations (Scopus)


Terminal investment hypothesis is a longstanding theoretical idea that organisms should increase their reproductive effort as their prospects for survival and reproduction decline. However, numerous attempts to test the terminal investment in reproduction have yielded contradictory results. This study reports an experimental confirmation of the terminal investment hypothesis. It was predicted that immune-challenged yellow mealworm beetles (Tenebrio molitor) are more likely to follow terminal investment strategy when their food resources are limited. Our results suggest the key role of food resources while making decisions to follow a terminal investment strategy. We found that male individuals invested in their sexual attractiveness at the expense of immune response and survival when food was not available. In contrast, the beetles did not decrease their lifespan and did not invest in the attractiveness of their sex odours under conditions of food ad libitum. Our results show the importance of food availability and quality in understanding the evolution of reproductive strategies.

Original languageEnglish
Pages (from-to)339-345
Number of pages7
Issue number2
Publication statusPublished - Jan 13 2015



  • Reproduction
  • Resources
  • Sexual attractiveness
  • Tenebrio molitor
  • Terminal investment

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

Cite this

Krams, I. A., Krama, T., Moore, F. R., Rantala, M. J., Mänd, R., Mierauskas, P., & Mänd, M. (2015). Resource availability as a proxy for terminal investment in a beetle. Oecologia, 178(2), 339-345.