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The effects of alkaloids on the feeding behavior of gypsy moth larvae
Author(s) -
Shields Vonnie D.C.,
Smith Kristen P.,
Shaw Taharah E.,
Arnold Nicole S.,
Gordon Ineta M.
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a462-a
Subject(s) - lymantria dispar , gypsy moth , biology , lepidoptera genitalia , larva , botany , insect , pest analysis , deciduous , crop , context (archaeology) , horticulture , agronomy , paleontology
The gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), is a major defoliator of forest habitats in North America. These larvae feed on the foliage of hundreds of plants, but prefer leaves from deciduous hardwood trees such as sweetgum, maple, and oak. Plants contain a variety of phytochemicals, some of which are insect feeding deterrents. Deterrent compounds influence the food selection of many phytophagous insects including gypsy moth larvae. Deterrent compounds, such as alkaloids, are generally unfavored and typically avoided by these larvae. We tested the effects of eight alkaloids using two‐choice feeding bioassays. Each alkaloid was applied to glass fiber disks and red oak leaf disks. All eight alkaloids tested on glass fiber disks were deterrent to varying degrees. When these alkaloids were applied to leaf disks, however, only seven were still deterrent. Of these seven, five were less deterrent on leaf disks compared with glass fiber disks, indicating that their potency was dramatically reduced when they were applied to leaf disks. The reduction in deterrency may be attributed to the phagostimulatory effect of red oak leaves in suppressing the negative deterrent effect of these alkaloids, suggesting that individual alkaloids may confer context‐dependent deterrent effects in plants in which they occur. We also tested the effects of these eight alkaloids at six concentrations spanning four logarithmetic steps to determine deterrent threshold effects. This study provides novel insights into the feeding behavioral responses of gypsy moth larvae to selected deterrent alkaloids. Our results may be potentially useful in designing crop protection strategies from insect pests and will help to improve our understanding of insect feeding behavior. Supported by NIH grant 1 R15 DC007609‐01 to V.S. and Bridges NIH grant 5R25GM058264‐03.