Defensive Compounds and Male-Produced Sex Pheromone of the Stink Bug, Agroecus griseus

Abstract

Agroecus griseus is a serious corn pest in Brazil. Contents of the dorsal abdominal glands (DAGs) in nymphs, and the metathoracic gland (MTG) in adults of this species were characterized and quantified. Compounds found were similar to those of other Pentatomidae species and included aliphatic hydrocarbons, aldehydes, oxo-alkenals, and esters. However, two compounds were found in the MTG that have not been described previously for this family. Mass spectrometry, infrared spectroscopy, and gas chromatographic analysis using coinjection with authentic standards confirmed the identities of the compounds as enantiopure (S)-2-methylbutyl acetate and 3-methyl-2-butenyl acetate. The five nymphal instars showed significantly different ratios of components, mainly between those of the first and later instars. No significant differences were detected in MTG contents between sexes. Gas chromatography (GC) analysis of aeration extracts of males and females showed the presence of a compound released exclusively by males. Gas chromatography - electroantennographic detection (GC-EAD) assays indicated that the male-specific compound is bioactive in females, suggesting the presence of an attractant pheromone. The mass spectrum and infrared data for this compound matched with methyl 2,6,10-trimethyltridecanoate, a sex pheromone component previously detected in the stink bugs, Euschistus heros and E. obscurus. The synthetic standard coeluted with the natural pheromone on two different GC stationary phases, confirming the proposed structure. Y-tube olfactometer assays showed that the synthetic standard was strongly attractive to females, and GC-EAD tests produced responses with antennae from females similar to those of the natural pheromone.

Identification of the Alarm Pheromone of Hygia lativentris and Changes in Composition during Development

“…One of the characteristic features before and after this metamorphosis is change in chemical composition between nymphs and adults. Two patterns of nymph-adult chemical polymorphisms have been identified: nymphs and adults possess completely different sets of components (e.g., Prestwich 1976;Prudic et al 2008), and nymphs and adults have a series of common components with their own lifestage-specific components (e.g., Farine et al 1993;Fávaro et al 2012;Noge et al 2012a). Additionally, in some cases, composition changes have been detected during adult stages in which a higher amount of an ester has been detected only from newly molted adults (Aldrich and Yonke 1975;Aldrich et al 1978;Prestwich 1976).…”

“…The identification of heteropteran pheromones is important in order to incorporate pheromones into pest management (e.g., Fávaro et al 2012;Yasuda and Higuchi 2012;Zarbin et al 2012). Findings also have contributed to a deeper understanding of the biological aspects of Heteroptera mediated by certain chemical signals.…”

Identification of male-produced aggregation pheromone of the curculionid beetle Acrotomopus atropunctellus

“…A balloon filled with hydrogen was attached to the vial and, after flushing, the mixture was stirred for 8 h at room temperature. The mixture was filtered through a cotton plug in a Pasteur pipette and analyzed by GC-MS (Favaro et al , 2012).…”

Identificaton of the Alarm and Sex Pheromones of the Leaf‑Footed Bug, Leptoglossus zonatus (Heteroptera: Coreidae)

“…Male and female glass traps were eluted with 400 μL of double distilled HPLC grade hexane to collect the volatiles released by each sex and stored at -20 °C until analysis. 17 Extracts from male and female were collected every 24 h for comparison.…”