Calibrating post-feeding detection times of ingested weed seeds by carabid beetles
Carabid beetles are an abundant group of beetles frequently encountered in arable land. As regular consumers of weed seeds, they are potential candidates for the provision of natural weed seed regulation in agricultural land. Recently, molecular analysis of carabid regurgitates have been employed to reveal the in-field seed choice of carabids. To increase the explanatory power of molecular approaches, however, the applied methods need to be calibrated for a range of realistic seed-predator interactions depending on the degree of predator specialization.
In the present project, we hypothesize that (i) seed specialist granivores digest their preferred seed species faster than generalist granivores, (ii) not-preferred seeds are digested slower by specialists in comparison to generalists, (iii) specialist and generalist granivorous carabids digest seeds faster than predominantly carnivorous carabids and finally, (iv) a combined diet of seeds and animal prey alters seed DNA detection, depending on the carabid species identity.
To test these hypotheses, feeding experiments including three carabid species associated to the different feeding specializations and three weed seed species will be conducted. The gut content of the beetles will be tested for amplifiable DNA from consumed seeds at five different time points to assess the effect of time post-feeding and the species identity of both consumer (i.e. carabid) and food (i.e. seed).
The results gained from these calibratory feeding experiments will allow making more profound interpretations of molecular gut content analysis of field derived samples from granivorous carabid communities. The proposed cooperation of the partner institution paves the way for future joint research in the field of more sustainable solutions in agricultural pest management.
The project is financed by the Federal Ministry Republic Austria for Education Science and Research (OEAD) in cooperation with Pavel Saska and Hana Foffová (Crop Research Institute, Praha) from the Czech Republic.
ATE members involved:
- Corinna Wallinger (PI)
- Veronika Neidel (PhD. student)