scholarly journals Effects of Tissue Phosphorus and Nitrogen in Impatiens wallerana on Western Flower Thrips (Frankliniella occidentalis) Population Levels and Plant Damage

HortScience ◽  
2004 ◽  
Vol 39 (3) ◽  
pp. 545-550 ◽  
Author(s):  
Yan Chen ◽  
Kimberly A. Williams ◽  
Brent K. Harbaugh ◽  
Michelle L. Bell
Keyword(s):  
Vegetative Growth ◽  
Growth Stage ◽  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Plant Size ◽  
Flower Thrips ◽  
N Rates ◽  
Nitrogen Rates ◽  
Tissue Phosphorus ◽  
Impatiens Wallerana

Host-plant nutritional status may affect the incidence and development of western flower thrips (WFT; Frankliniella occidentalis Pergande). Two greenhouse experiments were conducted to determine the responses of WFT population levels on impatiens (Impatiens wallerana Hook.f.) when plants were fertilized with commercially practiced rates of nitrogen (N) and phosphorus (P). Impatiens `Dazzler Violet' were grown with nutrient treatment combinations of 2 N rates (8 and 20 mm) by 2 P rates (0.32 and 1.28 mm). Individual plants grown in thrips-proof cages were inoculated with WFT at 2 or 4 weeks after transplant, in separate experiments, representing vegetative or reproductive stages of plant growth, respectively. Plants were destructively sampled weekly for 4 weeks following inoculation. Plant tissue N and P concentrations were significantly different across treatments: 8 and 20 mm N resulted in 4.9% and 6.3% N in tissue, respectively; 0.32 and 1.28 mm P resulted in 0.37% and 0.77% P in tissue, respectively. Nitrogen rates had no effect on WFT population levels. However, 4 weeks after inoculation with adult female WFT during the vegetative growth stage, plants fertilized with 1.28 mm P had more adult WFT than those fertilized with 0.32 mm P. Feeding damage varied depending on whether plants were inoculated in the vegetative stage with adult WFT or during reproductive growth with immature WFT. Plant size and number of flowers were lower in plants inoculated during the vegetative growth stage with adult WFT but were not affected when inoculation with immature WFT occurred during the reproductive stage, as most WFT were found feeding inside the nectariferous spurs of the flowers. Tissue N was lower in WFT-inoculated plants compared to noninoculated plants in both experiments.

scholarly journals Cultivar, Fertilizer, and Irrigation Affect Vegetative Growth and Susceptibility of Chrysanthemum to Western Flower Thrips

1998 ◽  
Vol 123 (4) ◽  
pp. 727-733 ◽  
Author(s):  
Ursula K. Schuch ◽  
Richard A. Redak ◽  
James A. Bethke
Keyword(s):  
Leaf Area ◽  
Frankliniella Occidentalis ◽  
Growth Habit ◽  
Western Flower Thrips ◽  
Dry Mass ◽  
Varietal Resistance ◽  
Flower Thrips ◽  
Irrigation Solution ◽  
Liquid Fertilization ◽  
N Rates

`Fontana', `Iridon', `Pink Lady', `Splendor', `White Diamond', and `White View Time' chrysanthemum (Dendranthema × grandiflorum Ramat.) were grown for 10 weeks with N rates of 80, 160, or 240 mg·L-1 constant liquid fertilization and irrigated at sufficient (high) or deficient (low) amount. Cultivars differed in growth habit, and treatments significantly affected all variables measured. Plants fertilized with 80 mg·L-1 had lower leaf and stem dry mass, less leaf area, and were deficient in leaf N compared with plants fertilized with twice the amount of N. The highest stem dry mass was produced with 160 mg·L-1. Leaf and stem dry mass were reduced 25% for plants receiving low irrigation compared to those receiving high irrigation. In general, leaf area increased when fertilizer was raised from 80 to 160 mg·L-1 but differed by cultivar and irrigation regime when fertilizer was increased to 240 mg·L-1. Three weeks after the experiment started, electrical conductivity (EC) of runoff collected weekly from `White Diamond' plants fertilized with 240 mg·L-1 exceeded the average EC of the irrigation solution. The 240 mg·L-1 treatment also resulted in excessive EC in the growing substrate at the end of the experiment and reduced stem dry mass by 11% compared with the 160 mg·L-1 fertilizer regime. Substrate EC differed between cultivars in response to fertilizer and irrigation. Significantly more adult western flower thrips [Frankliniella occidentalis (Pergrande)], 55% and 52%, were found on the foliage of `Pink Lady' and `Fontana', respectively, than on `Iridon'. `Pink Lady' and `Fontana' had more immature thrips at the end of the experiment than `Iridon' and `White View Time'. Fewer adults and immatures were found on plants fertilized with 80 mg·L-1 than 240 mg·L-1. Fewer adults were detected in plants under high versus low irrigation, while irrigation had no effect on the number of immatures. The simultaneous use of plant varietal resistance and plant cultural growing techniques has the potential to lower thrips populations on chrysanthemum.

scholarly journals Resistance to Western Flower Thrips Feeding Damage in Impatiens Populations from Costa Rica

HortScience ◽  
2003 ◽  
Vol 38 (7) ◽  
pp. 1424-1427 ◽  
Author(s):  
Daniel F. Warnock
Keyword(s):  
Costa Rica ◽  
Plant Resistance ◽  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Breeding Program ◽  
Feeding Damage ◽  
Single Population ◽  
Flower Thrips ◽  
Susceptible Control ◽  
Impatiens Wallerana

Western flower thrips (WFT) [Frankliniella occidentalis (Pergande)] is a pest of greenhouse-grown floriculture crops worldwide. To determine if plant resistance varied in three populations of impatiens (Impatiens wallerana Hook. f.) collected near San Vito, Costa Rica, 59 genotypes were evaluated for resistance to feeding by WFT. Individual insect-free plants of each genotype were inoculated with 20 laboratory-reared WFT. Thrips were allowed to feed on individual plants for a 4-week period followed by visual evaluations to estimate feeding damage. Feeding damage varied among genotypes. Thirty-seven genotypes had feeding damage levels similar to the susceptible control, while 22 entries were significantly more resistant than the susceptible control. Of the 22 genotypes with some level of resistance, six genotypes were commercially acceptable, having mean visual ratings below 4.0 on a 1 to 9 evaluation scale. Five of these six genotypes were seedlings from a single population and represented 13.9% of the seedlings in that population. The remaining seedling was from a second San Vito population. The plants in these populations identified as having acceptable levels of damage may be useful in a breeding program designed to enhance resistance to WFT feeding damage. Because WFT feeding damage varied among genotypes, the potential for improving impatiens resistance to WFT exists within available germplasm.

scholarly journals Resistance of Impatiens Germplasm to Western Flower Thrips Feeding Damage

HortScience ◽  
2002 ◽  
Vol 37 (5) ◽  
pp. 802-804 ◽  
Author(s):  
Bejie Herrin ◽  
Daniel Warnock
Keyword(s):  
Host Plant ◽  
Plant Resistance ◽  
Host Plant Resistance ◽  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Present Problem ◽  
Feeding Damage ◽  
Wild Type ◽  
Flower Thrips ◽  
Impatiens Wallerana

Western flower thrips (WFT) [Frankliniella occidentalis (Pergande)] are an ever-present problem in greenhouse floricultural crops. To determine if host plant resistance varied in impatiens [Impatiens wallerana Hook. f.] nine genotypes were evaluated for resistance to WFT feeding damage. Individual insect-free plants of each genotype were inoculated with ≈30 laboratory-reared WFT. Thrips were allowed to feed on individual plants for a 4-week period during which visual evaluations were conducted every 2 weeks to estimate feeding damage. Feeding damage varied among genotypes and increased with time. At 4 weeks after inoculation, `Cajun Carmine' and `Super Elfin Lavender' had significantly less feeding damage than all other genotypes. The San Vito Wild-type germplasm was determined to be highly susceptible to thrips feeding damage based on visual evaluations. Because WFT feeding damage varied among genotypes, the potential for improving impatiens resistance to WFT exists within commercially available germplasm.

scholarly journals Morphological and Chemical Factors Related to Western Flower Thrips Resistance in the Ornamental Gladiolus

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1384
Author(s):  
Dinar S. C. Wahyuni ◽  
Young Hae Choi ◽  
Kirsten A. Leiss ◽  
Peter G. L. Klinkhamer
Keyword(s):  
Host Plant ◽  
Plant Resistance ◽  
Host Plant Resistance ◽  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Resistance Breeding ◽  
Breeding Programs ◽  
Triterpenoid Saponins ◽  
Flower Thrips ◽  
Highly Correlated

Understanding the mechanisms involved in host plant resistance opens the way for improved resistance breeding programs by using the traits involved as markers. Pest management is a major problem in cultivation of ornamentals. Gladiolus (Gladiolus hybridus L.) is an economically important ornamental in the Netherlands. Gladiolus is especially sensitive to attack by western flower thrips (Frankliniella occidentalis (Pergande) (Thysanoptera:Thripidae)). The objective of this study was, therefore, to investigate morphological and chemical markers for resistance breeding to western flower thrips in Gladiolus varieties. We measured thrips damage of 14 Gladiolus varieties in a whole-plant thrips bioassay and related this to morphological traits with a focus on papillae density. Moreover, we studied chemical host plant resistance to using an eco-metabolomic approach comparing the 1H NMR profiles of thrips resistant and susceptible varieties representing a broad range of papillae densities. Thrips damage varied strongly among varieties: the most susceptible variety showed 130 times more damage than the most resistant one. Varieties with low thrips damage had shorter mesophylls and epidermal cells, as well as a higher density of epicuticular papillae. All three traits related to thrips damage were highly correlated with each other. We observed a number of metabolites related to resistance against thrips: two unidentified triterpenoid saponins and the amino acids alanine and threonine. All these compounds were highly correlated amongst each other as well as to the density of papillae. These correlations suggest that papillae are involved in resistance to thrips by producing and/or storing compounds causing thrips resistance. Although it is not possible to distinguish the individual effects of morphological and chemical traits statistically, our results show that papillae density is an easy marker in Gladiolus-breeding programs targeted at increased resistance to thrips.

Stability of spinosad resistance inFrankliniella occidentalis(Pergande) under laboratory conditions

2008 ◽  
Vol 98 (4) ◽  
pp. 355-359 ◽  
Author(s):  
P. Bielza ◽  
V. Quinto ◽  
C. Grávalos ◽  
E. Fernández ◽  
J. Abellán ◽  
...  
Keyword(s):  
Resistant Strain ◽  
Selection Pressure ◽  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Laboratory Conditions ◽  
Flower Thrips ◽  
Factors Influencing ◽  
Stability Of Resistance ◽  
The Stability ◽  
Successive Generations

AbstractThe stability of spinosad resistance in western flower thrips (WFT),Frankliniella occidentalis(Pergande), populations with differing initial frequencies of resistance was studied in laboratory conditions. The stability of resistance was assessed in bimonthly residual bioassays in five populations with initial frequencies of 100, 75, 50, 25 and 0% of resistant individuals. There were no consistent changes in susceptibility of the susceptible strain after eight months without insecticide pressure. In the resistant strain, very highly resistant to spinosad (RF50>23,000-fold), resistance was maintained up to eight months without further exposure to spinosad. In the absence of any immigration of susceptible genes into the population, resistance was stable. In the case of the population with different initial frequency of resistant thrips, spinosad resistance declined significantly two months later in the absence of selection pressure. With successive generations, these strains did not change significantly in sensitivity. Spinosad resistance inF. occidentalisdeclined significantly in the absence of selection pressure and the presence of susceptible WFT. These results suggest that spinosad resistance probably is unstable under field conditions, primarily due to the immigration of susceptible WFT. Factors influencing stability or reversion of spinosad resistance are discussed.

Virus Decline of Strawberry in California and the Role of Insect Vectors and Associated Viruses

2015 ◽  
Vol 16 (4) ◽  
pp. 211-215 ◽  
Author(s):  
Surendra K. Dara
Keyword(s):  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Trialeurodes Vaporariorum ◽  
Current Status ◽  
Insect Vectors ◽  
The Past ◽  
Disease Vector ◽  
Flower Thrips ◽  
Purple Coloration

Greenhouse white fly, Trialeurodes vaporariorum (Westwood); western flower thrips, Frankliniella occidentalis (Pergande); and strawberry aphid, Chaetosiphon fragaefolii (Cockerell), are common pests of strawberries in California and are vectors of one or more viruses. Most of the viruses transmitted by these vectors do not cause symptoms on strawberry when the infection occurs individually. However, when one of the viruses (Beet pseudoyellows virus or Strawberry pallidosis-associated virus) transmitted by T. vaporariorum is present along with one of the viruses transmitted by F. occidentalis, C. fragaefolii, or other sources, it results in a virus decline of strawberry, which can cause significant crop losses. Stunted root and plant growth, purple coloration of foliage, and dieback of the plant are some of the symptoms associated with virus decline. Increases in T. vaporariorum infestations during the past few years significantly elevated the risk of whitefly as a crop pest and a disease vector. This article reviews virus decline of strawberry, symptoms of infection, and the current status of insect vectors in California strawberries. Accepted for publication 17 November 2015. Published 20 November 2015.

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