Posts Tagged ‘Defense’

Boeing to consolidate defense and space sites

St. Louis (UPI) Nov 16, 2016

Boeing is preparing to consolidate Defense, Space & Security facilities to streamline operations.
Under the new plan, the aerospace giant will reduce its facilities space by approximately 4.5 million square feet. Boei…

Cats as “unintelligent design”?

So news aggregator Digg labelled a story by Britt Peterson at Atlantic. Curious are the cultural assumptions around design in nature. Anyway, The animal so many dote on is among the world’s most destructive predators. New Zealand’s recent announcement of a plan to eradicate all invasive predators, including feral cats, sparked an immediate response—and not […]

Variability in plant nutrients reduces insect herbivore performance

The performance and population dynamics of insect herbivores depend on the nutritive and defensive traits of their host plants1. The literature on plant-herbivore interactions focuses on plant trait means2,3,4, but recent studies showing the importance of plant genetic diversity for herbivores suggest that plant trait variance may be equally important5,6. The consequences of plant trait variance for herbivore performance, however, have been largely overlooked. Here we report an extensive assessment of the effects of within-population plant trait variance on herbivore performance using 457 performance datasets from 53 species of insect herbivores. We found that variance in plant nutritive traits substantially reduces mean herbivore performance via nonlinear averaging of performance relationships that were overwhelmingly concave-down. In contrast, relationships between herbivore performance and plant defense levels were typically linear, such that plant defense variance does not affect herbivore performance via nonlinear averaging. Our results demonstrate that plants contribute to the suppression of herbivore populations by having variable nutrient levels, not just by having low average quality as is typically thought. We propose that this phenomenon could play a key role in the suppression of herbivore populations in natural systems, and that increased nutrient heterogeneity within agricultural crops could contribute to the sustainable control of insect pests in agroecosystems.

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