Foraging behaviour and resource utilization of the aphid parasitoid Pauesia unilachni: adaptation to host distribution and mortality risks |
| |
Authors: | Wolfgang Völkl and Werner Kraus |
| |
Institution: | (1) Department of Animal Ecology I, University of Bayreuth, P.O. Box 10 12 51, D-95440 Bayreuth, Germany;(2) Department of Didactics in Biology, University of Bayreuth, P.O. Box 10 12 51, D-95440 Bayreuth, Germany |
| |
Abstract: | Pauesia unilachni is a parasitoid of the grey pine aphid, Schizolachnus pineti which feeds on needles of Scots pine. P. unilachni females displayed a dual movement system when foraging within a pine. They left a colony usually by foot and searched nearby needles intensively, thereby ensuring a maximum probability to encounter neighbouring S. pineti colonies. If search by foot was not successful, parasitoids changed their behaviour and searched needles by flight to cover larger distances. This behaviour was consistent both on uninfested and S. pineti-infested trees in the laboratory and in the field. In total, females allocated a 15-fold amount of time into search by foot compared to search by flight, although the overall foraging success, i.e. the number of discovered host colonies, did not differ significantly between the two movement types. However, the reduction of searching time by flight involved also higher travel mortality risks. In the field, P. unilachni got frequently entangled in spider nets when searching by flight and were killed. |
| |
Keywords: | Aphidiidae Aphididae Schizolachnus pineti search patterns host distribution foraging success mortality risks |
本文献已被 SpringerLink 等数据库收录! |
|