| Title: | "Identification of two sex pheromone components of the potato aphid, Macrosiphum euphorbiae (Thomas)" |
| Author(s): | Goldansaz SH; Dewhirst S; Birkett MA; Hooper AM; Smiley DW; Pickett JA; Wadhams L; McNeil JN; |
| Address: | "Departement de biologie, Universite Laval, Ste-Foy, Quebec Canada G1K 7P4" |
| DOI: | 10.1023/b:joec.0000028434.19319.b4 |
| ISSN/ISBN: | 0098-0331 (Print) 0098-0331 (Linking) |
| Abstract: | "Females of the potato aphid Macrosiphum euphorbiae exhibit typical calling behavior, with virgin female oviparae raising their back legs off the substrate to release sex pheromone from glands on the tibia. Airborne collections from calling oviparae were analyzed by GC and GC-MS to determine if, like the majority of aphids examined to date, they produced (1R,4aS,7S,7aR)-nepetalactol (1) and (4aS,7S,7aR)-nepetalactone (2). Both components were present and produced in ratios that varied with age from 4:1 to 2:1. The relative stereochemical configurations of these components were determined by GC-coinjection of the aphid-derived sample with synthetic standards on both HP-1 and DB-Wax GC columns. The absolute stereochemical configuration of the nepetalactol (determined from approximately 15 microg of material in an air entrainment sample) was determined as (1R,4aS,7S,7aR)-1 by derivatization of the aphid sample with (S)-(+)-alpha-methoxy-alpha-(trifluoromethyl)phenylacetyl chloride (Mosher's acid chloride) to generate a diastereoisomer that was compared to synthetic samples by NMR spectroscopy and GC. In bioassays in the wind tunnel, M. euphorbiae males responded to potato plants with oviparae but not to unattacked plants or those infested with parthenogenetically reproducing apterae. In no-choice laboratory bioassays, the same level of male response was observed to virgins and to the 3:1-5:1 synthetic blends of nepetalactol (1):nepetalactone (2). However, the time taken to reach the source was significantly less to virgin females than to the synthetic pheromone blends. In all cases, males walked rather than flew to the source. Males showed lower responses to a 1:1 synthetic mixture and did not respond to either of the components when presented alone. Under field conditions, few M. euphorbiae males were captured in traps baited with different ratios of the synthetic pheromone. Possible reasons for the different responses under laboratory and field conditions are discussed" |
| Keywords: | "Animals Aphids/*chemistry/*physiology Bridged Bicyclo Compounds, Heterocyclic/*analysis Cyclopentane Monoterpenes Cyclopentanes/*analysis Female Gas Chromatography-Mass Spectrometry Magnetic Resonance Spectroscopy Male Molecular Conformation Molecular Str;" |
| Notes: | "MedlineGoldansaz, Seyed H Dewhirst, Sarah Birkett, Michael A Hooper, Antony M Smiley, Diane W M Pickett, John A Wadhams, Lester McNeil, Jeremy N eng 2004/07/21 J Chem Ecol. 2004 Apr; 30(4):819-34. doi: 10.1023/b:joec.0000028434.19319.b4" |
