Ramat Hanadiv Forum 9.11.2016
The meeting will take place on Wednesday, November 9st, between 13:30-14:30, at the auditorium, visitors pavilion
Many insects are plant-dwelling (PDI). Since mammalian herbivores (MH) exploit the same recourse, it is likely that they will frequently encounter one another. While indirect interactions, i.e. plant mediated, between MH and PDI are well documented, direct interactions between the two (such as ingestion and trampling) have received little attention. It is not yet clear whether MH are attracted, deterred or indifferent to the presence of PDI on their food plants. For the first time I have examined the direct interactions between goats (MH) and spring webworm caterpillars, Ocnogyna loewii (PDI), which are both polyphagous and abundant in Mediterranean-type habitats. This study includes a series of controlled trials with goats. I examined the influence caterpillars have on the goats diet selection, feeding behavior and efficiency and the influence the goats have on the caterpillars' survival. I found that the goat's accessibility to the food plant is not influenced by the presence of caterpillars. The goats will feed from infested plants at a slower rate than non-infested plants (66% reduction) and they abandon their feeding posts faster. This occurs since the goats are not interested in ingesting caterpillars. Accordingly, they perform a series of behaviors (that will be described in the lecture) that reduce the chance of accidently ingesting caterpillars while feeding. As a result, 98% of the caterpillars inhabiting the plants survive. The goats do not use their sight to detect the caterpillars, rather their keen sense of smell and the physical contact (touch) of the caterpillars with their sensitive and mobile lips. In this study, we witness for the first time that MH can cope with insect infested plants and that they have behavioral mechanisms that assist them in avoiding incidental predation of insects. This indicates that the direct interactions between MH and PDI are prevalent and significant.