Parasitoid control of aphids in organic and conventional farming systems

Macfadyen, Sarina; Gibson, Rachel; Raso, Lorna; Sint, Daniela; Traugott, Michael; Memmott, Jane

doi:10.1016/j.agee.2009.04.012

Cited by 62 publications

(40 citation statements)

References 20 publications

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“…This result suggests that the structure of feeding interactions may change in situations when primary parasitoids play a stronger role, such as in structurally complex landscapes. However, an increased taxonomic resolution based on the analysis of aphid–parasitoid species interactions via molecular approaches (Traugott et al 2008; Macfadyen et al 2009b) is likely to contribute to a better understanding of multi-trophic interactions and may also reveal hidden interactions, such as facultative hyperparasitism by primary parasitoids or trophic loops within the guild of mummy parasitoids.…”

Section: Discussionmentioning

confidence: 99%

Farming practices change food web structures in cereal aphid–parasitoid–hyperparasitoid communities

2012

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Section: Discussionmentioning

confidence: 99%

Farming practices change food web structures in cereal aphid–parasitoid–hyperparasitoid communities

2012

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“…Second, we hypothesized that urban warming increases P. quercifex abundance by decreasing parasitism. To test this hypothesis, we measured percent parasitism [18] of P. quercifex in hot and cold sites. Third, we tested the hypothesis that urban warming increases P. quercifex abundance by increasing P. quercifex fecundity.…”

Section: Introductionmentioning

confidence: 99%

Urban Warming Drives Insect Pest Abundance on Street Trees

et al. 2013

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Cities profoundly alter biological communities, favoring some species over others, though the mechanisms that govern these changes are largely unknown. Herbivorous arthropod pests are often more abundant in urban than in rural areas, and urban outbreaks have been attributed to reduced control by predators and parasitoids and to increased susceptibility of stressed urban plants. These hypotheses, however, leave many outbreaks unexplained and fail to predict variation in pest abundance within cities. Here we show that the abundance of a common insect pest is positively related to temperature even when controlling for other habitat characteristics. The scale insect Parthenolecanium quercifex was 13 times more abundant on willow oak trees in the hottest parts of Raleigh, NC, in the southeastern United States, than in cooler areas, though parasitism rates were similar. We further separated the effects of heat from those of natural enemies and plant quality in a greenhouse reciprocal transplant experiment. P. quercifex collected from hot urban trees became more abundant in hot greenhouses than in cool greenhouses, whereas the abundance of P. quercifex collected from cooler urban trees remained low in hot and cool greenhouses. Parthenolecanium quercifex living in urban hot spots succeed with warming, and they do so because some demes have either acclimatized or adapted to high temperatures. Our results provide the first evidence that heat can be a key driver of insect pest outbreaks on urban trees. Since urban warming is similar in magnitude to global warming predicted in the next 50 years, pest abundance on city trees may foreshadow widespread outbreaks as natural forests also grow warmer.

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“…The typically short generation times of the species involved mean that responses to environmental change can happen quickly, and these systems have already proven useful to measure community-level impacts of land use (MacFadyen et al, 2009;Tylianakis et al, 2007). The population dynamics of host-parasitoid interactions have been studied extensively (Hassell, 2000) and models of pair-wise species interactions have been extended to describe the dynamics of at least simple experimental communities very successfully (Bonsall and Hassell, 1998;van Veen et al, 2005).…”

Section: Ecological Network In a Changing Climatementioning

confidence: 99%