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ARS Home » Southeast Area » Tifton, Georgia » Southeast Watershed Research » Research » Publications at this Location » Publication #336337
Title: Reinvestigation of Cactoblastis Captorum (LEPIDOPTERA: PYRALIDAE) sex pheromone for improved attractiveness and greater specificity

Author
item CIBRIAN-TOVAR, JUAN - Colegio De Postgraduados
item CARPENTER, JAMES - Retired ARS Employee
item Hight, Stephen
item Potter, Thomas
item GUILLERMO, LOGARZO - South American Biological Control Lab(SABCL)
item GONZALEZ, J - Colegio De Postgraduados

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 10/28/2016
Publication Date: 4/5/2017
Citation: Cibrian-Tovar, J., Carpenter, J.E., Hight, S.D., Potter, T.L., Guillermo, L., Gonzalez, J.C. 2017. Reinvestigation of Cactoblastis Captorum (LEPIDOPTERA: PYRALIDAE) sex pheromone for improved attractiveness and greater specificity. In: Shields, V., editor. Biological Control of Pest and Vector Insects. Rijeka, Croatia: INTECH. p. 119-131. http://dx.doi.org/10.5772/66638.

Interpretive Summary: The cactus moth, which is native to Argentina and neighboring Uruguay and Paraguay, was successfully used for biocontrol of invasive cactus species in Australia and South Africa. Most recently it was used in the Leeward island group of the Caribbean for cactus control and as a result it is now found throughout Caribbean, along the Gulf Coast of Mexico and in the southeastern United States where it threatens native cactus populations. The moth’s control and management requires traps that can be used to monitor populations in the field. This has been accomplished with some success using traps baited with the insect’s pheromone, i.e. the mixture of chemicals that female moth releases to attract males for mating. To optimize traps we reanalyzed the pheromone obtained from a cactus moths from a colony maintained at the USDAS-ARS Crop Protection laboratory in Tifton, GA. We applied an analytical technique, solid phase micro extraction (SPME) that is commonly used in food and flavor and environmental analysis. Using SPME we successfully analyzed the pheromone by touching the sex gland of a single “calling” moth. The technique was also used to measure the pheromone emitted into the air by a single moth held in an enclosed container. Findings confirmed that the pheromone is comprised of four compounds with two accounting for more than 90% of the mixture. Using SPME we also compared the pheromone composition of moths raised on artificial and natural diets and found no difference. In field studies conducted in Argentina we compared the performance of traps prepared using only the two major components of the pheromone to commercially available traps. Our traps prepared with the binary mixture trapped significantly more moths. Better performance combined with lower costs of the traps we prepared suggest that they should be used in on-going efforts to monitor the spread of this invasive insect in Mexico and the southeastern USA.

Technical Abstract: Cactoblastis cactorum (Berg.) is recognized as an invasive species in the Caribbean, United States, and Mexico with potential to adversely impact native cactus population. Prior work using hexane extracts of sex glands showed that the sex pheromone of this species has 54% of (Z, E) -9.12 tetradecadien-1-ol acetate (Z9, E12-14: Ac), 42% of (Z, E) -9.12 tetradecadien-1-ol (Z9, E12-14: OH) and 4% of Z9-tetradecen-1-ol acetate (Z9-14: Ac). Although traps baited with this mixture are effectively to attract males of the cactus moth it is necessary to determine whether the pheromone can be optimized and to determinate if female diet may impact pheromone composition. Experiments with insects were made at the USDA-ARS Crop Protection and Management Research Unit Laboratory in Tifton, Georgia, where there is a colony maintained on cactus and another on an artificial diet. SPME was used to collect pheromones in the headspace above a single calling female and by rubbing the excised female sex gland with SPME fibers. Rubbing the gland directly with SPME fiber revealed that the pheromone consists of the compounds cited above plus Z9-14:Ac. In the headspace analysis, the two principal constituents detected in the pheromone mixture were founded. The methodology with dynamic aeration and capture of volatiles with fiber only captured two compounds. In addition, our results indicated that natural or artificial diet not influence the composition of the sex pheromone. Field experiments with new mixtures of compounds were made in Pampa, Muyoj, Argentina. Of the eight mixtures evaluated in the field, more moths were captured (F=2.56. P value = 0.02) with binary mixtures of the di-unsaturated acetate and di-unsaturated alcohol in 60:40 proportion. Using two component mixtures as bait will likely make traps less expensive while providing capture efficiencies that are equal to or greater than commercial traps that are currently available that use four components and therefore more expensive.