1. Most communities of insect herbivores are unlikely to be structured by resource competition, but they may be structured by apparent competition mediated by shared natural enemies. 2. The potential of three guilds of natural enemies (parasitoids, fungal entomopathogens and predators) to influence aphid community structure through indirect interactions is assessed. Based on the biology, we pre...

1. Insect host–parasite systems allow investigations of the trophodynamics of ecological communities within a well-formed theoretical context. A little explored feature of such systems involves the interplay between generalized consumers and host–parasitoid dynamics. I report a study investigating how the impacts of generalized consumers, viewed here as interaction modifications, may influence ...

Fly pupae, primarily house fly (Musca domestica Linnaeus) and stable fly (Stomoxys calcitrans (Linnaeus)) (Diptera: Muscidae), were collected from a poultry house in northern Indiana, and parasitoid wasps developing in them were allowed to emerge. Fly pupae density, relative species abundance, and size varied with collection date. Four species of parasitoid wasps were reared from the fly pupae:...

1. The strength of interaction between the specialist parasitoid Cotesia melitaearum and the host butterfly Melitaea cinxia is influenced by the coincidence of the adult stage of the parasitoid with the larval stage of the host. 2. We show that there is great variation in this developmental synchrony among local populations and among years, ranging from complete synchrony to complete asynchrony...

Recent declines in biodiversity have increased interest in the link between biodiversity and the provision and sustainability of ecosystem services across space and time. We mapped the complex network of interactions between herbivores and parasitoids to examine the relationship between parasitoid species richness, functional group diversity and the provision of natural pest control services. Q...

Parasitoids are among the most important natural enemies of insects in many environments. Acyrthosiphon pisum, the pea aphid, is a common pest of the leguminous crops in temperate regions. Pea aphids are frequently attacked by a range of endoparasitic wasps, including the common aphidiine, Aphidius ervi. Immunity to parasitoid attack is thought to involve secondary symbiotic bacteria, the prese...

The effects of host age and parasitoid female age on the occurrence of 'Pseudoparasitism', using the Spodoptera littoralis-Microplitis rufiventris host-parasitoid system were investigated. The first four larval instars of the host are not equally suitable for parasitoid development. The proportion of pseudoparasitized hosts significantly increases when: (1) the age of the female parasitoid incr...

Few empirical studies have directly explored the association between Buchnera aphidicola (Enterobacteriales: Enterobacteriaceae), the primary endosymbiont of aphids, and the life history strategies of aphid parasitoids. A series of paired-choice experiments were conducted to explore the preference of the parasitoid Lysiphlebus ambiguus Halliday (Hymenoptera: Aphididae) for symbiotic and aposymb...