Submitted to: Experimental Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 9, 2002
Publication Date: N/A
Interpretive Summary: The Colorado potato beetle (CPB) is one of the most damaging pests of potatoes in the United States, Europe, and other potato growing regions worldwide. New approaches to manage the CPB are desperately needed as it rapidly develops resistance to pesticides and even genetically-modified plants. Further, the public has been slow to accept products from genetically modified organisms. An alternative to pesticides might utilize plant or insect-produced attractants as components of control strategies. Such attractants were sought for nearly 75 years until ARS Scientists recently identified the first synthetic plant attractants for CPB. The identification and synthesis of a male-produced pheromone that is attractive to both sexes of CPB is reported. This discovery breaks a paradigm of a female-produced attractant for this insect and provides an additional tool for use in biorational control. This aggregation pheromone may be used by entomologists to selectively survey or capture CP populations using traps, and by chemists and entomologists as a component of an attracticide or use in combination with a feeding deterrent in the "push-pull" strategy for insect control.
Technical Abstract: A male-produced aggregation pheromone was identified for the Colorado potato beetle (CPB) Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae). While male beetles produced only minor amounts of the pheromone, its production could be more than 100 fold enhanced by topical application of juvenile hormone III, antennectomy, or the combined treatment of JH III and antennectomy; this enhancement facilitated the identification of the compound as (S)-3,7-dimethyl-2-oxo-oct-6-ene-1,3-diol [= (S)-CPB I], a unique structure for an insect pheromone. Antennal receptors of both sexes responded selectively to the (S)-enantiomer. Both male and female CPB were attracted to serial source loads of (S)-CPB I in laboratory bioassays; (R)-CPB I was inactive or inhibitory as evidenced by the inactivity of the racemate. This is the first identification of a pheromone for the CPB and differs from the paradigm of a female-produced pheromone for this insect. The attractant is also the first male-produced pheromone identified for the Chrysomelidae.