scholarly journals Ultrasound Treatments to Control Surface Pests of Fruit

2001 ◽  
Vol 11 (2) ◽  
pp. 186-188 ◽  
Author(s):  
James D. Hansen

Durations of ultrasound treatments were evaluated for efficacy in removing or destroying external pests of apples (Malus sylvestris var domestica). Egg hatch of codling moth (Cydia pomonella; Lepidoptera: Tortricidae), was inversely related to time of ultrasound exposure, although egg mortality was less than 60% after 45 min of treatment. Mortality of twospotted spider mite (Tetranychus urticae; Acari: Tetranychidae), and western flower thrips (Frankliniella occidentalis; Thysanoptera: Thripidae), was directly related to ultrasound durations; adding detergent to the ultrasound bath increased treatment efficacy. Ultrasound did not remove san jose scale (Quadraspidiotus perniciosus; Homoptera: Diaspididae), from the fruit surface. Ultrasound, which can be incorporated in the packing line, shows promise as a postharvest phytosanitation treatment against external pests.

2001 ◽  
Vol 133 (3) ◽  
pp. 413-428 ◽  
Author(s):  
A.L. Knight ◽  
B.A. Christianson ◽  
T.R. Unruh ◽  
G. Puterka ◽  
D.M. Glenn

AbstractThe impact of multiple applications of the kaolin-based particle film M96-018 on the population density of selected pests of apple, Malus domestica (Borkh) (Rosaceae), and their natural enemy populations were measured in several Washington State orchards from 1997 to 1999. Densities of western tentiform leafminer, Phyllonorycter elmaella (Doganlar and Mutuura) (Lepidoptera: Gracillariidae), were significantly higher and percent parasitism was generally lower in treated plots than in untreated plots. The effect of M96-018 on green aphids (Aphis spp.) (Hemiptera: Aphididae) was variable between orchards; however, populations of rosy apple aphid, Dysaphis plantaginea Passerini (Hemiptera: Aphididae), were higher in treated plots than in untreated plots. M96-018 reduced the mean density of the white apple leafhopper, Typhlocyba pomaria (McAtee) (Hemiptera: Cicadellidae), and the density of spiders (Araneae) compared with untreated plots. Fruit injury by codling moth, Cydia pomonella (L.), and fruittree leafroller, Archips argyrospilus (Walker) (Lepidoptera: Tortricidae), was significantly reduced in the treated plots compared with the untreated plots. The effect of M96-018 on the mullein bug, Campylomma verbasci (Meyer) (Hemiptera: Miridae), was variable between orchards and years. Stink bug (Hemiptera: Pentatomidae) density and related fruit injury were unaffected by M96-018. Fruit infestation by San Jose scale, Quadraspidiotus perniciosus (Comstock) (Hemiptera: Diaspididae), was significantly higher in treated plots than in untreated plots. Discontinuing applications of M96-018 at mid-season reduced the number of aphid-infested leaves and increased fruit injury by leafroller compared with a full-season program. No differences in pest densities occurred in plots treated for one versus two consecutive years; however, the density of phytophagous mites (Acari: Tetranychidae) was significantly higher the subsequent year after plots were treated with M96-018. Further studies are needed to elucidate how these disruptive impacts of particle films can be minimized.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1384
Author(s):  
Dinar S. C. Wahyuni ◽  
Young Hae Choi ◽  
Kirsten A. Leiss ◽  
Peter G. L. Klinkhamer

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.


2008 ◽  
Vol 98 (4) ◽  
pp. 355-359 ◽  
Author(s):  
P. Bielza ◽  
V. Quinto ◽  
C. Grávalos ◽  
E. Fernández ◽  
J. Abellán ◽  
...  

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.


2015 ◽  
Vol 16 (4) ◽  
pp. 211-215 ◽  
Author(s):  
Surendra K. Dara

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.


1984 ◽  
Vol 116 (8) ◽  
pp. 1057-1062 ◽  
Author(s):  
H. R. Moffitt ◽  
K. D. Mantey ◽  
G. Tamaki

AbstractIn laboratory and field studies with the codling moth, Cydia pomonella (L.), TH 6043 and TH 6044, experimental benzoylphenyl urea chitin-synthesis inhibitors, were as effective as diflubenzuron in reducing egg hatch and subsequent larval entry when eggs were deposited on previously treated fruits or foliage. All three compounds exhibited extended residual activity, with significant reductions in egg hatch occurring over a 19-week period. TH 6045 exhibited little activity against codling moth. All compounds tested were relatively ineffective in reducing egg hatch or subsequent larval entry when they were applied topically to deposited eggs, except for the red ring stage of development which was slightly affected.


2008 ◽  
Vol 9 (1) ◽  
pp. 30 ◽  
Author(s):  
Mrittunjai Srivastava ◽  
Lara Bosco ◽  
Joe Funderburk ◽  
Anthony Weiss

Feeding by the western flower thrips, Frankliniella occidentalis, causes damage to the fruits of pepper, and the species is the key vector of Tomato spotted wilt virus. Effective management integrates conservation of populations of the natural predator, Orius insidiosus, with the use of reduced-risk insecticides, namely spinosad. We conducted field experiments in northern Florida in 2005 and 2006 and in central Florida in 2006 to evaluate the new reduced-risk insecticide spinetoram for control of thrips and to determine the impact on natural populations of O. insidiosus. Spinetoram at 61 g ai/ha was as effective as spinosad at 140 g ai/ha against the western flower thrips and the other common thrips in Florida, Frankliniella tritici and Frankliniella bispinosa. The mean numbers of the predator were very high in all treatments in each experiment, and their numbers relative to the numbers of thrips indicated that predation was sufficient to suppress thrips populations in all treatments. Broad-spectrum insecticides when included in the experiments provided little or no control; sometimes, they flared thrips numbers compared to untreated pepper. Accepted for publication 25 October 2007. Published 18 January 2008.


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