Nitrogen and water availability to tomato plants triggers bottom-up effects on the leafminer Tuta absoluta

Abstract

This study examined the effects of various levels of nitrogen inputs (optimal, insufficient and excessive) and water inputs (optimal, low drought and high drought) to tomato plants (Solanum lycopersicum) on survival and development of an invasive tomato leafminer, Tuta absoluta (Meytick) (Lepidoptera: Gelechiidae). Plant growth i.e. plant height and the number of nodes declined under insufficient or excessive nitrogen treatment. Compared to optimal N, insufficient N treatment decreased leaf N content and increased the carbon/nitrogen ratio (C/N) whereas an excess of N had no effect on both leaf N content and leaf C/N ratio. Sub-optimal nitrogen supplies, water treatments and their interactions, significantly reduced the leafminer survival rate and slowed down its development. Together with the findings from three recent companion studies, we assumed that a combination of changes in nutritional value and chemical defense could explain these observed effects. Furthermore, our findings supported both the “Plant vigor hypothesis” and the “Nitrogen limitation hypothesis”.

Nitrogen and water limitations in tomato plants trigger negative bottom-up effects on the omnivorous predator Macrolophus pygmaeus

“…Marmande) were grown from seeds in a climatic chamber (L:D 12:12, 24 ± 1°C, 65 ± 5 % RH) as reported by Han et al (2014). Germination was carried out in small plastic pots (7 9 7 9 6.5 cm, TEKU, Rixheim, France) filled with compost (Tonusol, Draguignan, France).…”

“…Nutritional treatment design was adapted from Han et al (2014); it was based on previous knowledge acquired on the tomato plant (see Le Bot et al 2009;Larbat et al 2012Larbat et al , 2014 and established from optimal conditions ensuring maximal growth of tomato plants in our lab conditions (see details in Han et al 2014). From DAS 8, a full nutrient solution adjusted to pH 5.5 was supplied daily to plants in a fully crossed design combining two nitrogen levels (optimal nitrogen [ON] vs. insufficient nitrogen [IN]) with two water levels (optimal water [OW] vs. drought [DT]).…”

Ecological fitness of brown planthopper, Nilaparvata lugens (Stål), to rice nutrient management

“…Nutrient application changes the host-plant morphology, biochemistry, and physiology, which improves nutritional conditions for herbivores (Bernays 1990), thus playing a key role on insects. Nitrogen (N) content is one of the most important performance limiting factors of herbivores (De Bruyn et al 2002;Facknath and Lalljee 2005;Kerpel et al 2006;Lu et al 2007;Lu and Heong 2009;Han et al 2014;Oliveira et al 2014;Rashid et al 2016aRashid et al , b, 2017. In the present study, survival rate of both nymph and adult BPHs was markedly higher on N-enriched plant than Ndeficient one, and it was almost double and triple for nymph and adult respectively.…”

Drought-stressed tomato plants trigger bottom-up effects on key mite pests

“…Yet, the relationship between arthropod outbreaks and drought is not consistent, depending on the timing, intensity and water stress phenology (Huberty and Denno, 2004) and on the feeding guild that the herbivore belongs to (Inbar et al, 2001). It is widely accepted that drought stress triggers significant alterations in plant biochemistry and metabolism (Hummel et al, 2010) that may alter the physiology of the host plant and modify the nutritional values, affecting herbivore performance (Han et al, 2014).…”

“…Yet, the relationship between arthropod outbreaks and drought is not consistent, depending on the timing, intensity and water stress phenology (Huberty and Denno, 2004) and on the feeding guild that the herbivore belongs to (Inbar et al, 2001). It is widely accepted that drought stress triggers significant alterations in plant biochemistry and metabolism (Hummel et al, 2010) that may alter the physiology of the host plant and modify the nutritional values, affecting herbivore performance (Han et al, 2014).There are several hypotheses concerning the response of the plant to drought stress and how herbivores adapt to those changes (Huberty and Denno, 2004;Cornelissen et al, 2008;White, 2009). Drought induces metabolic changes in the plant, such as increased levels of free sugars and free essential amino acids, which according to the "Plant stress hypothesis" causes the plant to have a higher nutritional value for herbivores (White, 1984;Inbar et al, 2001;White, 2009), and can play an important role in herbivore outbreaks (Guo et al, 2013;Johnson et al, 2014).…”