|AHN, SEUNG-JOON - Max Planck Institute For Biogeochemistry|
|PARK, KYE-CHUNG - Horticulture And Food Research Institute|
|Vander Meer, Robert - Bob|
|CARDE, RING - University Of California|
|JURENKA, RUSSELL - Iowa State University|
Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/28/2016
Publication Date: 5/7/2016
Citation: Choi, M.Y., Ahn, S., Park, K., Vander Meer, R.K., Carde, R.T., Jurenka, R. 2016. Tarsi of male heliothine moths contain aldehydes and butyrate esters as potential pheromone components. Journal of Chemical Ecology. 42(5):425-432. doi: 10.1007/s10886-016-0701-3.
Interpretive Summary: Insect moths are major pests of agriculture throughout the world, and their control is responsible for the largest use of chemical pesticides. As a chemical alternative and green chemicals the use of insect pheromones is becoming more popular because they are environment friendly control tools to protect many economic crops and animals. A major moth group, Helicoverpa and Heliothis genera, is the most speciose moth group because these two genera contain agriculturally important pests, their mating behaviors, sex pheromone components and blend ratios, and application of their pheromones in management have been well studied. Decades ago major and minor pheromone components of these moths have been identified from their female pheromone glands, and currently being utilized for controlling those pests. Scientists from USDA-ARS at Corvallis, OR and Gainesville, FL, Max Planck Institute in Germany, Horticulture and Food Research Institute in New Zealand, and University of California, Riverside, California identified a large amount of 16:Ald and octadecanal (18:Ald) on male legs of four moth species. The main source of 16:Ald in males is the tarsi; with little or none detected on other leg parts. A comparatively small amount of 16:Ald was found on female tarsi. In addition, scientists found that a series of butyrate esters that are localized on the tarsi can be transferred to a substrate while walking on a glass surface. They suggest that the male aldehydes and butyrate esters could play a role in courtship choice by females. This is the first report that a known female sex pheromone component has been identified from the legs of nocturnal moths, and provide a clue to use pheromonal application
Technical Abstract: The Noctuidae is one of the most specious moth families and contains the genera Helicoverpa and Heliothis. Their major sex pheromone component is (Z)-11-hexadecenal except for Helicoverpa assulta and Helicoverpa gelotopoeon both of which utilize (Z)-9-hexadecenal. The minor components of heliothine sex pheromones 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 (µg levels) of hexadecanal and octadecanal on the male legs 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 in the other leg parts including tibia, femur, trochanter and coxa. A relatively small amount of hexadecanal was found on female tarsi. This is the first time that a known sex pheromone component was identified from the legs of nocturnal moths. Large amounts of butyrate esters (about 16 µg) were found on tarsi of males with lower amounts on female tarsi. Males released the butyrate esters when 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 electroantennograms, female antennae had a higher response to hexadecanal than did male antennae. We discuss the possible role of aldehydes and butyrate esters as courtship signals in the short-range mating process of heliothine moths.