AGRO 244 |
| Nonnative species caused approximately $137 billion per year in ecological damage and loss in the United States. Among these foreign species is the Argentine ant, Linepithema humile, which is native in South America and has been introduced to Mediterranean climates worldwide. In its introduced range, intraspecific aggression is greatly reduced, colony boundaries are dissolved, and individuals mix freely among physically distinct nests leading to the formation of extensive supercolonies. To understand the mechanisms underlying this social structure, it is important to elucidate the nestmate recognition system in this species. In social insects, recognition cues are chemical in nature and contained in the lipid layer on the cuticle. In Argentine ants, the cuticular profile is composed mainly of linear hydrocarbon molecules of 33 or more carbons with at least one side chain methyl group. The goal of this research is to synthesize pure hydrocarbons believed to be responsible for nestmate recognition and test the effects on ant recognition. Linear hydrocarbons of 35-37 carbons with one to three methyl group side chains were synthesized. The ants were coated with known hydrocarbons identified as potential key elements in intercolony recognition (Figure 1). The ants' reactions were observed to a treated nestmate. While treatment with synthetic control alkanes did not cause an aggressive response, ants treated with synthetic versions of the candidate compounds were attacked by their nestmates. Identification of the essential hydrocarbons for nestmate recognition can permit control over aggression between nestmates by altering cuticular hydrocarbon profile. If successful, this could enable better control over this pest.
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Characterizing Natural Products as Pesticides, Repellents, or Biomarkers
1:00 PM-3:50 PM, Thursday, 14 September 2006 San Francisco Marriott -- Salon 2, Oral
Division of Agrochemicals |
