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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Insect Genetics and Biochemistry Research » Research » Publications at this Location » Publication #132668
Title: METHYL-BRANCHED ALKANES ON THE SURFACE OF MALE AND FEMALE ADULTS, AND EGGS OF THE COLORADO POTATO BEETLE, LEPTINOTARSA DECEMLINEATA

Author
item Nelson, Dennis
item Fatland, Charlotte
item Adams, Terrance

Submitted to: Molecular Insect Science International Symposium Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 3/27/2002
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The Colorado potato beetle, Leptinotarsa decemlineata (Say), is the major defoliator of potato worldwide. It can also be a major pest of tomatoes and egg plant and can quickly develop resistance to insecticides. Host plant resistance is one method of potential control and a novel mechanism of resistance has been identified (Balbyshev and Lorenzen, 1997). The leaves of a Solanum spp. hybrid are hypersensitive to the egg mass resulting in formation and subsequent detachment of a necrotic zone containing the egg mass, which falls to the ground, exposing the eggs and subsequent nymphs to ground dwelling predators. Material causing the necrosis was associated with the egg mass and remains unknown. The hydrocarbons of the eggs resembled those of the adults both qualitatively and in methyl-branch positions. Hydrocarbons are the major component of the cuticular lipids of adult males and females and show little sexual dimorphism in either the chromatographic profiles or in the structures of the methyl-branched components. Straight-chain alkanes are essentially absent from all stages but also are difficult to detect because unique methyl branching causes branched alkanes to elute with similar retention times to those of n¿alkanes. The beetle is unique from other arthropods studied in that it has a preponderance of methylalkanes (mono-, di- and trimethyl-branched) with the first methyl branch on carbon 2. Each stage had two major components: one was a mixture of 2,10,16- and 2,10,18-trimethyltetratriacontanes (10-11%) males, females and eggs; the other was 2-methyltriacontane (11-12%) in males and females, but in the eggs was 2,6-dimethyltriacontane (11%). Tetramethylalkanes were trace components and one was identified, 13,17,21,25-tetramethylheptatriacontane. The major hydrocarbon class was the 2,x-dimethylalkanes, 30 and 40%, in females and eggs, respectively, while males had 23%. The major hydrocarbon class in males was the internally branched dimethylalkanes, 26%.