Journal of Economic Entomology (2013) 106, 2354-2363

E.J. Bernklau, B.E. Hibbard and L.B. Bjostad (2013)
Isolation and characterization of host recognition cues in corn roots for larvae of the western corn rootworm (Coleoptera: Chrysomelidae)
Journal of Economic Entomology 106 (6), 2354-2363
Abstract: Behavioral bioassays were used to isolate compounds from germinating corn roots that elicit a host recognition response (tight-turning behavior) by neonate larvae of the western corn rootworm Diabrotica virgifera virgifera LeConte. When a behaviorally active extract of germinating corn roots was separated into an aqueous partition and a hexane partition, significantly more larvae (P < 0.05) responded to the recombined partitions than to either partition alone, demonstrating that the active material is a blend comprising both polar and nonpolar compounds. When the aqueous partition was separated with reverse-phase solid phase extraction, most of the behavioral activity was retained in the 100% water fraction (F-1). Gas chromatography-mass spectrometry analysis determined that F-1 contained a blend of small sugars, diacids, amino acids, and inorganic compounds. The nonpolar partition was separated on a silica column, and the resulting fractions were tested in combination with F-1 from the aqueous separation. More than 70% of larvae responded to the 100% acetone fraction (fraction B) in combination with F-1, and the response to this treatment was significantly higher than responses to the other nonpolar fractions or to F-1 alone. Methyl esterification of fraction B, followed by gas chromatographic fatty acid methyl ester analysis, confirmed that fraction B primarily consisted of lipids containing fatty acyl groups.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Bruce E. Hibbard

Research topic(s) for pests/diseases/weeds:
pheromones/attractants/traps
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Diabrotica virgifera