Impact of abiotic factors on predator-prey interactions: DNA-based gut content analysis in a microcosm experiment.
Bull Entomol Res
; 98(3): 257-61, 2008 Jun.
Article
em En
| MEDLINE
| ID: mdl-18439346
ABSTRACT
The effects of predators on prey populations can be modified by a number of abiotic factors. Here, we investigated the combined and separate effects of rain and ground-dwelling predators on aphid populations in a microcosm experiment lasting for 21 days, using PCR to analyse the gut content of the predators. Rain significantly dislodged aphids from shoots and ears by 57% and 25%, respectively. The gut content analysis showed that more predators consumed aphids in the rain treatment than without rain, indicating higher availability of aphids to ground-dwelling predators after rain. However, no synergistic effects of rain and ground-dwelling predators on aphid population development could be demonstrated. Rain alone significantly decreased aphid populations by 27%, suggesting that this is a significant mortality factor. Predators alone had no significant effect on aphid numbers, but the gut content analyses showed aphid consumption also in the no-rain treatments, indicating that aphids were available to the predators on the soil surface even without rain. Our results suggest that weather conditions such as rain can modify predator-prey interactions in the field. Employing PCR-based predator gut content analyses proved to be useful as trophic links could be directly verified.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Afídeos
/
Chuva
/
Besouros
/
Ecossistema
/
Comportamento Alimentar
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article