scholarly journals The Artificial Sweetener, Erythritol, Has Insecticidal Properties Against Pear Psylla (Hemiptera: Psyllidae)

2020 ◽  
Vol 113 (5) ◽  
pp. 2293-2299 ◽  
Author(s):  
Katie Wentz ◽  
W Rodney Cooper ◽  
David R Horton ◽  
Robert Kao ◽  
Louis B Nottingham
Keyword(s):  
Survival Time ◽  
Insecticidal Activity ◽  
Field Experiments ◽  
Human Consumption ◽  
Artificial Sweetener ◽  
Natural Field ◽  
Pear Psylla ◽  
Foliar Treatment ◽  
Pear Trees ◽  
Phloem Feeding

Abstract Erythritol is a dietary sweetener that is used for low-calorie or diabetic diets. Although safe for human consumption, erythritol is lethal to certain Dipteran pests, but insecticidal effects of erythritol on phloem-feeding insects have yet to be examined. Our goal was to determine whether erythritol has insecticidal activity against pear psylla, Cacopsylla pyricola (Foerster) (Hemiptera: Psyllidae). We first demonstrated that ingestion of erythritol solutions compared with water by pear psylla caused reduced feeding, impaired motor functions, and reduced survival time of adults. We then tested whether foliar treatment of pear leaves with erythritol was also lethal to pear psylla. Foliar treatment of erythritol led to reduced 3-d survival of pear psylla nymphs and adults, and reduced rates of oviposition by pear psylla adults. Psylla adults also preferred to settle on untreated leaves than on erythritol-treated leaves in preference assays. Finally, we conducted field experiments to test whether applications of erythritol provided pear trees with protection against pear psylla under natural field conditions. Those experiments showed a reduction in pear psylla nymphs on erythritol-treated trees compared with untreated trees, but only if the erythritol was completely dissolved into solution by heating. Laboratory trials confirmed the importance of heating. Results of our experiments demonstrate that erythritol is insecticidal to pear psylla nymphs and adults and provide the first report that erythritol is lethal to a phloem-feeding insect. These findings suggest that erythritol may provide a new safe and effective tool for the management of pear psylla.

scholarly journals Efficacy of Spirotetramat in the Control of Pear Psylla (Cacopsylla Pyri L.) on Pear Trees in Poland

2012 ◽  
Vol 20 (2) ◽  
pp. 91-106 ◽  
Author(s):  
Krystyna Jaworska ◽  
Remigiusz W. Olszak ◽  
Barbara H. Łabanowska ◽  
Mirosław Korzeniowski
Keyword(s):  
Field Experiments ◽  
Early Stage ◽  
Single Application ◽  
Pest Population ◽  
Total Reduction ◽  
Cacopsylla Pyri ◽  
Summer Generation ◽  
Pear Psylla ◽  
Pear Trees ◽  
Very High

Abstract The effectiveness of spirotetramat in the control of pear psylla (Cacopsylla pyri) on pear trees was investigated in five field experiments, carried out in years 2009- 2011. One or two treatments were applied in June; the first treatment in the early stage of larvae hatching from eggs deposited by females from the summer generation, whilst the second application was carried out about two weeks later. In all the experiments, spirotetramat as Movento 100 SC applied at a dose of 2.25 l/ha effectively reduced the pest population after only a single application (total reduction of larvae after one week post-treatment 75.3-91.4%, and 83.7-97.6% at two weeks posttreatment). Movento 100 SC applied after a single application at a lower dose of 1.8 l/ha had a slightly worse effect (the total reduction of larvae at one week posttreatment was at the level of 58.4-91.3%, and two weeks after application at the level of 56-92.6%) - but in this case only a few larvae at stages L4 and L5 were found on pear shoots. The effectiveness of spirotetramat at both doses after two applications was very high.In comparison with standard insecticides the efficacy of spirotetramat was higher or not significantly different. In two experiments the application of standard compounds such as diflubenzuron and novaluron was not effective in controlling pear psylla and therefore did not prevent damage to pear trees. This may suggest that local populations of the pest are resistant to these measures, especially since they have been used for many years to control other pests of pear trees

scholarly journals Effects of Applications of Boron with Iron and Zinc on the Contents of Pear Trees

2016 ◽  
Vol 44 (1) ◽  
pp. 125-132 ◽  
Author(s):  
Serhat GÜREL ◽  
Haluk BAŞAR
Keyword(s):  
Field Experiments ◽  
Marmara Region ◽  
Control Soil ◽  
Pear Cultivar ◽  
Soil Application ◽  
South Eastern ◽  
Appropriate Treatment ◽  
Foliar Treatment ◽  
Iron And Zinc ◽  
Pear Trees

Boron (B) is an essential microelement for plants, animals and humans. The present study was conducted to evaluate theeffectiveness of various treatments for the correction of boron (B) with zinc (Zn) and iron (Fe) deficiencies in the pear cultivar ʻDeveciʼ in the south eastern Marmara region of Turkey. This work consisted of 4 field experiments that primarly included control, soil and foliar applications of B alone and in combination with Zn and Fe. Soil and foliar applications of borax increased B concentrations in leaves and fruit. However, foliar treatment with B was more effective than the soil application. Foliar applications of boron four times each season appeared to be an appropriate treatment for maintaining a sufficient B level in pear trees. Foliar applications of double and triple combinations of FeSO4.7H2O and ZnSO4.7H2O with borax significantly increased Fe and Zn concentrations in the leaves, as well. Boron concentrations were dramatically higher in the fruit parts(flesh and peel) than in the leaves. These results clearly indicated the translocation of B from soil and treated leaves to the fruits. Therefore, the B concentration in the fruit was more useful for the evaluation of B levels in pear trees.

scholarly journals How natural field experiments have enhanced our understanding of unemployment

2019 ◽  
Vol 3 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Omar Al-Ubaydli ◽  
John A. List
Keyword(s):  
Field Experiments ◽  
Natural Field

Management of Pear Psylla (Hemiptera: Psyllidae) Using Reflective Plastic Mulch

2020 ◽  
Vol 113 (6) ◽  
pp. 2840-2849
Author(s):  
Louis B Nottingham ◽  
Elizabeth H Beers
Keyword(s):  
Field Tests ◽  
Late Summer ◽  
The United States ◽  
Management Program ◽  
Plastic Mulch ◽  
Major Barrier ◽  
Reflected Light ◽  
Pear Psylla ◽  
Pear Trees ◽  
Black Plastic

Abstract Pear psylla, Cacopsylla pyricola (Förster), has remained the most challenging pest of commercial pears in Washington and Oregon, the top producers of pears in the United States. The lack of effective integrated pest management tactics for this pest has been a major barrier to effective management. In this study, we examined the potential for reflective plastic mulch affixed beneath pear trees to suppress pear psylla. In 2017 and 2018, single pear tree (cv. Bartlett) plots of reflective plastic mulch, black plastic mulch, and no mulch (check) were established in a research orchard to compare their effects on pear psylla. Arthropods were sampled every 7–14 d from March through late summer. In both years, reflective mulch plots had significantly fewer pear psylla adults, eggs, and nymphs of the first generation compared with black plastic and check plots. However, later generations of psylla were not suppressed by reflective mulch. Semi-field tests were conducted in 2019 and 2020 using uniformly pruned potted pear trees on either reflective plastic mulch or grass to determine whether summerform adults were tolerant to reflected light from mulch, or if shading from vegetative growth negated the effect of the mulch. In both years, significantly fewer summerform adults and eggs were found in reflective mulch plots, suggesting that shading, rather than summerform tolerance, reduced effects from reflective mulch in the summer. This study demonstrates the potential for reflective mulch to suppress pear psylla and justifies future examination as part of a season-long management program.

THE EFFECTS OF PETROLEUM OILS ON BARTLETT PEARS AND ON PEAR PSYLLA, PSYLLA PYRICOLA

1968 ◽  
Vol 100 (3) ◽  
pp. 290-295 ◽  
Author(s):  
Harold F. Madsen ◽  
K. Williams
Keyword(s):  
Panonychus Ulmi ◽  
Dormant Period ◽  
European Red Mite ◽  
Pear Psylla ◽  
Excellent Control ◽  
Pear Trees ◽  
Petroleum Oils

AbstractThe following oils were evaluated for control of the pear psylla, Psylla pyricola Foerster, phytotoxicity, and persistence on Bartlett pear trees; Orchex 696, Orchex 796 with 0.46% emulsifier, Orchex 796 with 1% emulsifier, PGSO-1, PGSO-2, and Volck Supreme. The oils were applied at the rate of 5 gal per acre in a three-spray program, one at the delayed dormant period and two during the summer.Orchex 796 (1% emulsifier) and Volck Superme oil gave the best control of pear psylla, PGSO-1 and PGSO-2 were intermediate, and Orchex 696 and Orchex 796 (0.46% emulsifier) were the least effective. Each of the oils gave excellent control of the European red mite, Panonychus ulmi (Koch).The oils caused enlargement and corkiness of the bark lenticels on 1-, 2-, and 3-year old wood. The pear fruits showed darker green lenticels than unsprayed fruit, but this green spotting did not persist when the pears were ripened.Analysis showed each oil to be persistent upon pear foliage. There was little loss after 8 days and an average of 28% loss after 25 days.

Sign in / Sign up

Export Citation Format

Share Document