Entomology Publications Entomology 5-2016 Tarsi of Male Heliothine Moths Contain Aldehydes and Butyrate Esters as Potential Pheromone Components Man-Yeon Choi U.S. Department of Agriculture Seung-Joon Ahn Max Planck Institute for Chemical Ecology Kye-Chung Park Horticulture and Food Research Institute Robert Vander Meer U.S. Department of Agriculture Ring T. Cardé University of California, Riverside See next page for additional authors Follow this and additional works at: https://lib.dr.iastate.edu/ent_pubs Part of the Behavior and Ethology Commons, Entomology Commons, and the Population Biology Commons The complete bibliographic information for this item can be found at https://lib.dr.iastate.edu/ ent_pubs/561. For information on how to cite this item, please visit http://lib.dr.iastate.edu/ howtocite.html. This Article is brought to you for free and open access by the Entomology at Iowa State University Digital Repository. It has been accepted for inclusion in Entomology Publications by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Tarsi of Male Heliothine Moths Contain Aldehydes and Butyrate Esters as Potential Pheromone Components Abstract The Noctuidae are one of the most speciose moth families and include the genera Helicoverpa and Heliothis. Females use (Z)-11-hexadecenal as the major component of their sex pheromones except for Helicoverpa assulta and Helicoverpa gelotopoeon, both of which utilize (Z)-9-hexadecenal. The minor compounds found in heliothine sex pheromone glands vary with species, but hexadecanal has been found in the pheromone gland of almost all heliothine females so far investigated. In this study, we found a large amount (0.5–1.5 μg) of hexadecanal and octadecanal on the legs of males of four heliothine species, Helicoverpa zea, Helicoverpa armigera, H. assulta, and Heliothis virescens. The hexadecanal was found on and released from the tarsi, and was in much lower levels or not detected on the remaining parts of the leg (tibia, femur, trochanter, and coxa). Lower amounts (0.05–0.5 μg) of hexadecanal were found on female tarsi. This is the first known sex pheromone compound to be identified from the legs of nocturnal moths. Large amounts of butyrate esters (about 16 μg) also were found on tarsi of males with lower amounts on female tarsi. Males deposited the butyrate esters while walking on a glass surface. Decapitation did not reduce the levels of hexadecanal on the tarsi of H. zea males, indicating that hexadecanal production is not under the same neuroendocrine regulation system as the production of female sex pheromone. Based on electroantennogram studies, female antennae had a relatively high response to hexadecanal compared to male antennae. We consider the possible role of aldehydes and butyrate esters as courtship signals in heliothine moths. Keywords Hexadecanal, Octadecanal, Butyrate esters, Heliothine moths, Male pheromones Disciplines Behavior and Ethology | Entomology | Population Biology Comments This article is published as Choi, Man-Yeon, Seung-Joon Ahn, Kye-Chung Park, Robert Vander Meer, Ring T. Cardé, and Russell Jurenka. "Tarsi of male Heliothine moths contain aldehydes and butyrate esters as potential pheromone components." Journal of chemical ecology 42, no. 5 (2016): 425-432. doi: 10.1007/ s10886-016-0701-3. Authors Man-Yeon Choi, Seung-Joon Ahn, Kye-Chung Park, Robert Vander Meer, Ring T. Cardé, and Russell Jurenka This article is available at Iowa State University Digital Repository: https://lib.dr.iastate.edu/ent_pubs/561 J Chem Ecol (2016) 42:425–432 DOI 10.1007/s10886-016-0701-3 Tarsi of Male Heliothine Moths Contain Aldehydes and Butyrate Esters as Potential Pheromone Components Man-Yeon Choi1 & Seung-Joon Ahn2 & Kye-Chung Park3 & Robert Vander Meer4 & Ring T. Cardé5 & Russell Jurenka6 Received: 6 January 2016 /Revised: 20 April 2016 /Accepted: 28 April 2016 /Published online: 7 May 2016 # Springer Science+Business Media New York 2016 Abstract The Noctuidae are one of the most speciose moth tarsi. This is the first known sex pheromone compound to be families and include the genera Helicoverpa and Heliothis. identified from the legs of nocturnal moths. Large amounts of Females use (Z)-11-hexadecenal as the major component of butyrate esters (about 16 μg) also were found on tarsi of males their sex pheromones except for Helicoverpa assulta and with lower amounts on female tarsi. Males deposited the bu- Helicoverpa gelotopoeon, both of which utilize (Z)-9- tyrate esters while walking on a glass surface. Decapitation hexadecenal. The minor compounds found in heliothine sex did not reduce the levels of hexadecanal on the tarsi of H. zea pheromone glands vary with species, but hexadecanal has males, indicating that hexadecanal production is not under the been found in the pheromone gland of almost all heliothine same neuroendocrine regulation system as the production of females so far investigated. In this study, we found a large female sex pheromone. Based on electroantennogram studies, amount (0.5–1.5 μg) of hexadecanal and octadecanal on the female antennae had a relatively high response to hexadecanal legs of males of four heliothine species, Helicoverpa zea, compared to male antennae. We consider the possible role of Helicoverpa armigera, H. assulta, and Heliothis virescens. aldehydes and butyrate esters as courtship signals in heliothine The hexadecanal was found on and released from the tarsi, moths. and was in much lower levels or not detected on the remaining parts of the leg (tibia, femur, trochanter, and coxa). Lower Keywords Hexadecanal . Octadecanal . Butyrate esters . amounts (0.05–0.5 μg) of hexadecanal were found on female Heliothine moths . Male pheromones Electronic supplementary material The online version of this article (doi:10.1007/s10886-016-0701-3) contains supplementary material, Introduction which is available to authorized users. * Russell Jurenka Sex attractant pheromones produced by female moths gener- [email protected] ally are either linear fatty acid-derived compounds, 12–18 carbons in chain length, with an oxygenated functional group 1 Horticultural Crops Research Laboratory, USDA-ARS, 3420 NW and one to three double bonds, or based on hydrocarbons with Orchard Avenue, Corvallis, OR 97330, USA a polyene and/or epoxide functional group. Pheromone blends 2 Department of Entomology, Max Planck Institute for Chemical comprised of multiple components are formed in species- Ecology, 07745 Jena, Germany specific ratios through pheromone biosynthetic pathways that 3 Horticulture and Food Research Institute, Gerald Street, involve fatty acid synthesis, desaturation, and limited chain- Lincoln 8152, New Zealand shortening along with reductases, oxidases, and acetyltrans- 4 Center for Medical, Agricultural, and Veterinary Entomology, ferases (Jurenka 2003; Tillman et al. 1999). USDA-ARS, Gainesville, FL 32608, USA The Noctuidae are one of the most speciose moth families 5 Department of Entomology, University of California, and includes the heliothine genera Helicoverpa and Heliothis. Riverside, CA 92521, USA Because these two genera contain agriculturally important 6 Department of Entomology, 434 Science II, Iowa State University, pests, their mating behaviors, sex pheromone components Ames, IA 50011, USA and blend ratios, and application of their pheromones in pest 426 J Chem Ecol (2016) 42:425–432 management have been well studied. To date all Helicoverpa at 25 °C ± 1 under a photoperiod of L:D 16:8 h and adults and Heliothis females investigated utilize (Z)-11-hexadecenal were provided with 10 % sucrose solution-soaked cotton ball (Z11–16:Ald) as a major component of the female sex phero- until tarsal extraction or bioassays. Helicoverpa armigera mone, except for Helicoverpa assulta and Helicoverpa used for electroantennogram (EAG) studies was supplied gelotopoeon, which use (Z)-9-hexadecenal (Z9–16:Ald) as from a stock culture kept at Plant & Food Research, the major pheromone component (Table S1)(Corkand Auckland, New Zealand. Lobos 2003; El-Sayed 2014; Sugie et al. 1991). Each species produces a specific pheromone blend. In particular, the ratio of Tarsal Extraction and Analysis Legs were detached from 2 two components, Z11–16:Ald and Z9–16:Ald, is crucial to to 3-d-old adults, and tarsi were excised from each leg by prevent inter-specific attraction between species of cutting the joint between tibia and tarsus. The six tarsi were Helicoverpa and Heliothis (Cork et al. 1992;El-Sayed immersed in 50 μl hexane containing (Z)-9-tetradecenal 2014). The identified minor components in pheromone glands (10 ng/μl) as an internal standard. Some extracts contained of heliothines are hexadecanal (16:Ald), (Z)-7-hexadecenal, n-tetratriacontane as an internal standard. The tarsi were re- tetradecanal, (Z)-9-tetradecenal, (Z)-11-hexadecenyl acetate, moved from the extraction vial after 10 min to 1 h at room (Z)-9-hexadecenyl acetate, (Z)-11-hexadecenyl alcohol, and temperature, and the extract was kept at −70 °C prior to chem- (Z)-9-hexadecenyl alcohol. These minor components in ical analysis. heliothines are found in varying amounts, and their possible Tarsal extracts from H. zea, H. virescens, H. armigera,and roles in mate attraction generally have not been clearly deter- H. assulta were analyzed by GC (6890 N; Agilent mined. To date, the minor gland component 16:Ald has been Technologies, Inc., Santa Clara, CA, USA) equipped with a found in all heliothine species. mass-selective detector (5975C; Agilent) and a DB-5 column Female sex pheromone glands in heliothine moths typical- (30 m × 0.25 mm ID, 0.25 μm film thickness, J&W Scientific, ly are located on the intersegmental cuticle between the 8th USA). The oven temperature was programed at 80 °C for and 9th abdominal segments just anterior to the ovipositor 1 min, increased to 170 °C at 5 °C/min, held for 3 min, and (Ma and Ramaswamy 2003). Male pheromone glands, on increased to 220 °C at 5 °C/min. Injector temperature was the other hand, have developed from abdominal tips, and form 250 °C.