Significance statement
Nitrogen limitation theory predicts that terrestrial plants should benefit from nitrogen inputs and subsequently that herbivores should benefit from higher plant protein contents. While this pattern has generally been supported, some herbivorous insects have shown preference and higher performance on low protein (p), high carbohydrate (c) diets as juveniles. However, little is known about the effects on reproduction in adults. Using nitrogen fertilizer, we demonstrate that high plant p:c has negative effects on Senegalese locust (Orthoptera: Oedaeleus senegalensis ) reproduction and survival in an agroecological setting (millet field, Pennisetum glaucum ). We hypothesize that this pattern will apply broadly to species that have extensive carbohydrate needs, such as long-distance migrators.
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