Abstract
The potential of using phytochemicals from leaves of wild tomato for controlling the two-spotted spider mite, Tetranychus urticae Koch, is explored in this study as a promising alternative to the use of synthetic pesticides. Wild tomato accessions of Lycopersicon hirsutum plants that are not consumed by humans were planted under greenhouse conditions for mass production of leaves. Crude extracts from leaves of three accessions of L. hirsutum, six accessions of L. hirsutum f. glabratum, and one accession each of L. pennellii and L. pimpinellifolium were prepared in chloroform, ethanol and hexane. Two spider mite bioassays, one a measure of antibiosis and the other a measure of repellency, were utilized to determine the acaricidal performance of the crude extracts. The bioassay for antibiosis was a 6-h no-choice test. The bioassay for repellency utilized a ring bioassay. Chloroform leaf extracts of L. hirsutum f. glabratum accessions (PI-251304, PI-134417, PI-134418, and PI-126449) exhibited greatest antibiotic activity on two-spotted spider mites; the hexane extracts exhibited greatest repellency. Extracts from PI-251304, PI-126449, PI-134417, and PI-134418 were especially lethal (chloroform) or repellent (hexane). We investigated differences in chemical composition of the crude leaf extracts that may explain the observed differences in mortality and repellency among the different accessions. Major chemical compounds (α-curcumene, α-zingiberene, trans-caryophyllene, 2-undecanone, and 2-tridecanone) known to have pesticidal efficacy were detected and quantified in the crude leaf extracts using a gas chromatograph (GC) equipped with a mass spectrometer (GC/MS). Lethality of extracts was mainly associated with the presence of high concentrations of 2-tridecanone; repellency of extracts was mainly associated with the presence of trans-caryophyllene. Leaf extracts of L. hirsutum f. glabratum accessions that contain significant quantities of 2-tridecanone and/or transcaryophyllene could be useful for managing populations of spider mites, which could reduce reliance on synthetic pesticides.
Original language | English |
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Pages (from-to) | 43-55 |
Number of pages | 13 |
Journal | Journal of Environmental Science and Health - Part B Pesticides, Food Contaminants, and Agricultural Wastes |
Volume | 41 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2006 |
Bibliographical note
Funding Information:We thank Rebecca Lee and Lisa Hawkins for their kind help in maintaining the greenhouse plants and Richard Thacker for maintaining the spider mite colony. This investigation was supported by two grants, USDA/CSREES No. KYX-10-03-37P and USDA/CSREES No. KYX-10-99-31P to Kentucky State University.
Funding
We thank Rebecca Lee and Lisa Hawkins for their kind help in maintaining the greenhouse plants and Richard Thacker for maintaining the spider mite colony. This investigation was supported by two grants, USDA/CSREES No. KYX-10-03-37P and USDA/CSREES No. KYX-10-99-31P to Kentucky State University.
Funders | Funder number |
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USDA-CSREES |
Keywords
- Leaf composition
- Leaf extracts
- Mass spectra
- Mortality
- Phytochemicals
ASJC Scopus subject areas
- Food Science
- Pollution