Flower nitrogen status and populations of Frankliniella occidentalis feeding on Lycopersicon esculentum

Abstract

In a 2‐year study, we manipulated flower chemistry of field grown Lycopersicon esculentum in North Florida and examined subsequent effects on populations of Frankliniella occidentalis. We examined variation in amino‐acid profiles and total nitrogen concentrations of flowers, flower number and plant size seasonally and in response to variable rates of nitrogen fertilization (202 kg ha−1 and 309 kg ha−1). Populations of F. occidentalis sampled every 6 to 10 days were then related to seasonal and treatment effects on plant variables. For both years, F. occidentalis was abundant on L. esculentum tomatoes for only short intervals (2–3 weeks), and populations were significantly higher on hosts receiving higher rates of nitrogen fertilization. Seasonal trends in F. occidentalis on L. esculentum were correlated to number of flowers per host plant, as well as concentrations of total nitrogen in flowers. Moreover, treatment (fertilization) effects were consistent with changes in the nitrogen status of flowers. Plants subjected to higher fertilization rates produced flowers that had higher nitrogen content as well as variations in amino‐acid profiles during the period of peak thrips populations. Abundance of F. occidentalis (particularly adult females) were most highly correlated to flower concentrations of phenylalanine during population peaks. Our results are consistent with beneficial effects of high dietary nitrogen to thrips populations, and also support the hypothesis that aromatic amino acids (e.g., phenylalanine) play a central role in the nutritional ecology of F. occidentalis.

Nitrogen fertilization sources and insecticidal activity of aqueous seeds extract of Carica papaya against Spodoptera frugiperda in maize

“…Some studies demonstrate that augmented nitrogen fertilizers increase populations of Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) in tomato (Brodbeck et al, 2001), Aphis gossypii Glover (Hemiptera: Aphididae) in cotton (Nevo and Coll, 2001), Nilaparvata lugens Stål and Sogatella furcifera Horvath (Hemiptera: Delphacidae) in rice (Lu et al, 2007). Other researchers have shown that populations of Ostrinia nubilaris Hubner (Lepidoptera: Crambidae) (Phelan et al, 1995), Diabrotica virgifera LeConte (Coleoptera: Chrysomelidae) (Moeser and Vidal, 2004) and Peregrinus maidis Ashmead (Hemiptera: Delphacidae) (Wang et al, 2006), increased in maize when fertilized with nitrogen.…”

Factors affecting herbivory of Thrips palmi (Thysanoptera: Thripidae) and Aphis gossypii (Homoptera: Aphididae) on the eggplant (Solanum melongena)

“…In this study, no effect of levels of N or K on leaves of eggplant with aphids and thrips was detected, what might be explained to low variations on levels of these compounds on leaves of this plant during the experimental period. Several authors have mentioned that high N levels were associated with aphids and thrips infestations on lettuce, tomato and cotton (Kennedy, 1958;Brodbeck et al, 2001;Cisneros and Godfrey, 2001;Nevo and Coll, 2001) being a key factor for increasing number of aphids in cotton (Cisneros and Godfrey, 2001). However, Leite et al (1999) showed no effect of 100 and 300 mg/kg and 0 and 200 mg/kg of N and K, respectively, in the soil on attack intensity of M. persicae on L. esculentum and on L. hirsutum f. glabratum (PI 134417) in greenhouse.…”

The Influence of Bahiagrass, Tillage, and cover crops on Organic Vegetable Production and Soil Quality in the Southern Coastal Plain

“…Plant biomass was dried at 42 o C until dry and weighed. Percent C and N from the plant biomass were measured by combustion in Year 3 only (Brodbeck et al, 2001). Total C and N were calculated by multiplying percentage by plant biomass weight.…”