Immature development of parasitoid wasps is restricted to resources found in a single host that is often similar in size to the adult parasitoid. When two or more parasitoids of the same or different species attack the same host, there is competition for monopolization of host resources. The success of intrinsic competition differs between parasitoids attacking growing hosts and parasitoids att...

Background: About 30 years ago, the Palaearctic fly Drosophila subobscura successfully invaded the New World, where parasitoid species diversity was thought to be lower than in the Old World. Hypotheses: Because parasitoids cause major mortality to Drosophila, the invader should benefit from escaping its natural parasitoid enemies and enjoy lower rates of parasitism than in the Old World. Also,...

Complex biotic interactions shape ecological communities of plants, herbivores and their natural enemies. In studies of multi-trophic interactions, the presence of small, invisible micro-organisms associated with plants and those of a fourth above-ground trophic level have often been neglected. Incorporating these neglected factors improves our understanding of the processes within a multi-trop...

Are there many of them about? Just a few! Current estimates suggest there may be between one half and two million species; they are found in virtually every terrestrial habitat, and in a few freshwater ones. They include the smallest known insects — the tiny eggparasitising mymarids — as well as giant ichneumon-flies with egg-laying apparatuses (ovipositors) up to several inches long. Pass a sw...

Title of Document: THE ROLE OF HOST-PLANT SPECIES IN THE DIFFERENTIATION OF SYMPATRIC POPULATIONS OF HYMENOPTERAN PARASITOIDS. Raul F. Medina, PhD, 2005 Directed By: Professor, Pedro Barbosa, Department of Entomology The biology and ecology of insect parasitoids is strongly influenced by the hostplant species on which their herbivorous hosts occur. Hymenopteran parasitoids in particular, presen...

The goals of this study were to identify pupal parasitoids of the asparagus miner, Ophiomyia simplex Loew (Diptera: Agromyzidae), and examine the effect of different diets and floral resources on the lifespan of adult asparagus miners and their parasitoids. We also measured the effect of parasitism on stem damage caused by the asparagus miner. The identity and abundance of the parasitoids of th...

Aphid parasitoids are common in Brazilian wheat fields, and parasitize aphids at the wheat tillering stage. However, there is little information available about when this natural enemy occurs in wheat crops. This study investigated the initial occurrence of aphid parasitoids in four commercial wheat crops in northern Paraná during the 2009 crop season. We installed two Malaise traps at each whe...

the sugar beet moth, scrobipalpa ocellatella boyd. (lep.: gelechidae( is the specific pest of beet. the aim of the present study was to identify the parasitoids of the moth. in this regard, sampling was conducted in fields of khorasan-e-razavi province during 2010 from early july until october. larvae and pupa were collected along with tubers of sugar beet and then were reared under controlled ...

The consequences of plant species loss are rarely assessed in a multi-trophic context and especially effects on life-history traits of organisms at higher trophic levels have remained largely unstudied. We used a grassland biodiversity experiment and measured the effects of two components of plant diversity, plant species richness and the presence of nitrogen-fixing legumes, on several life-his...

Host recognition and use in female parasitoids strongly relies on host fidelity, a plastic behavior which can significantly restrict the host preferences of parasitoids, thus reducing the gene flow between parasitoid populations attacking different insect hosts. However, the effect of migrant males on the genetic differentiation of populations has been frequently ignored in parasitoids, despite...