|
|
The parasitoid community of two microlepidopteran species living on hops
Hovorka, Tomáš ; Janšta, Petr (advisor) ; Libra, Martin (referee)
Interactions between parasitoids, phytophagous insects and their host plants play one of the crucial role in the trophic relationships of terrestrial food webs. According to current knowledge, more than half of all known terrestrial species are part of this food web (parasitoids- herbivores-plants). In many species of herbivore hosts, interactions with parasitoids have led to the evolution and diversification of different defense strategies. An example of a primary defense strategy against predators and parasitoids is the formation of shelters such as leaf mines, leaf cocoons or galls. These strategies are a key factor influencing the composition of the parasitoid community. In this thesis, the complex of parasitoids in two microlepidopteran species with different life strategies living on hops (Humulus lupulus) was investigated. The caterpillars of Caloptilia fidella (Lepidoptera: Gracillaridae) first mine within leaves of hops, later, when they start to feed exophagously, they create leaf rolls and cocoons on the outer surface of the leaf. Caterpillars of the species Cosmopterix zieglerella (Lepidoptera: Cosmopterigidae) remain in the mine throughout their larval development. The obtained parasitoids were identified both based on morphology and with the help of two gene fragments, namely CO1 and...
|
|
|
Community structure of caterpillar parasitoids from tropical rain forest
LIBRA, Martin
The aim of this dissertation is to investigate the community structure of parasitoids and their interactions with their hosts - caterpillars in the rainforest of Papua New Guinea, focusing on beta diversity and altitudinal trends. We show that parasitoid beta diversity is higher than the beta diversity of their hosts, which was also projected in their interactions. The altitude plays important role in the diversity of parasitoids, where we show that Ichneumonidae are more diverse at high elevation than at low elevation, which was not observed for other large insect families. Further, we performed a manipulative experiment, exposing live caterpillars in different elevations of tropical rainforest. Caterpillars faced similar mortality from parasitoids between elevations, but higher mortality from predation at low elevation. In the last chapter, we point out how important is correct species identification because wrong identification can misinterpret observed interactions.
|
|
|
Hymenopteran parasitoids (Hymenoptera: "Parasitica") and their impact on hosts species behaviour
Stiblík, Petr ; Janšta, Petr (advisor) ; Bogusch, Petr (referee)
Recently, many scientists have been focused on parasite or parasitoid host's manipulation. They don't describe only the changes in host behavior, but they even search for physiological background. Lots of papers dealing with hymenopteran parasitoids (Hymenoptera: Parasitica) host's manipulation have been published. The most studied are strongly adapted and host specific parasitoids, koinobionts. They developed very sophisticated mechanisms to manipulate their hosts for their own benefit. These parasitic wasps are not only very diverse group of the insect, but they even developed various ways to manipulate the hosts and their physiology. Sometimes the parasitoids use their hosts like a "food's vehicle", sometimes they manipulate just rates of some metabolites or suppress host's immune reaction. If the wasp's life-cycle is successful, the host does not develope to the adult's stage and is often consumed by the parasitoid larve.
|
|
|
Hymenopteran parasitoids (Hymenoptera: "Parasitica") and their impact on hosts species behaviour
Stiblík, Petr ; Janšta, Petr (advisor) ; Bogusch, Petr (referee)
Recently, many scientists have been focused on parasite or parasitoid host's manipulation. They don't describe only the changes in host behavior, but they even search for physiological background. Lots of papers dealing with hymenopteran parasitoids (Hymenoptera: Parasitica) host's manipulation have been published. The most studied are strongly adapted and host specific parasitoids, koinobionts. They developed very sophisticated mechanisms to manipulate their hosts for their own benefit. These parasitic wasps are not only very diverse group of the insect, but they even developed various ways to manipulate the hosts and their physiology. Sometimes the parasitoids use their hosts like a "food's vehicle", sometimes they manipulate just rates of some metabolites or suppress host's immune reaction. If the wasp's life-cycle is successful, the host does not develope to the adult's stage and is often consumed by the parasitoid larve.
|
guest ::
