Impact of nitrogen and potassium fertilization regimes on the biology of the tomato leaf miner Tuta absoluta

The tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), one of the most important lepidopteran pests of tomato (Solanum lycopersicum L.), was first introduced from South America into Spain in 2006. It has spread rapidly throughout the Mediterranean Basin, now threatens glasshouse production in Northern Europe. It is known that plant nutrient inputs may trigger bottom-up effects the performance of insect herbivores that feed on the plants. In this study, tomato plants fertilized with varying levels of nitrogen (N) and potassium (K) were used to study the effects of fertilization on the developmental rate, survival, reproduction and intrinsic rate of increase of T. absoluta. We found that T. absoluta that developed on tomato leaves from the plants treated with "high N - high K" as well as "high N - low K" had a significantly shorter development time and laid more eggs. Similarly, T. absoluta that fed on the leaves with high N - high K fertilization had a higher intrinsic rate of increase and net reproductive rate, and lower mean generation time and population doubling time. Varying K input did not affect all the biological traits of T. absoluta. Moreover, varying N-K treatments did not affect the adult longevity, preoviposition period and oviposition period. This information may be helpful to predict the population dynamics of T. absoluta and to slow its development by fertilization manipulation. Our current findings, combined with biological control, host plant resistance and other cultural practices, may be useful for Integrated Pest Management (IPM) programs against this pest.