title: Two compounds in bed bug feces are sufficient to elicit off-host aggregation by bed bugs, Cimex lectularius.
abstract: BACKGROUND
  After feeding, bed bugs aggregate in cracks and crevices near a host. Aggregation and arrestment are mediated by tactile and chemical stimuli associated with the bugs' feces and exuviae. Volatiles derived from fecally stained filter papers were analyzed by solid-phase microextraction (SPME) and evaluated using a multichoice behavioral assay to determine their impact on bed bug aggregation. In addition, crude fecal extracts were collected in methanol, analyzed by gas chromatography coupled with electroantennogram detection (GC-EAD) and mass spectrometry (GC-MS) and evaluated in open-air multichoice behavioral assays.
  
  
  RESULTS
  The SPME method was used to detect (E)-2-hexenal and (E)-2-octenal in heated bed bug feces. The presence of these two volatile components did not affect aggregation. Analysis of the crude fecal extracts revealed several semi-volatile nitrogenous compounds, a carboxylic acid and a sulfur-based compound. Adult antennae responded to compounds eluted from three regions of the crude extract using GC-EAD. A combination of two compounds, dimethyl trisulfide and methyldiethanolamine, resulted in aggregation responses equivalent to the original crude extract.
  
  
  CONCLUSIONS
  Bed bug aggregation is mediated by semi-volatile compounds derived from fecal extracts, and two compounds are sufficient to elicit aggregation. The two compounds identified here could be used to enhance the effectiveness of insecticidal applications or improve monitoring techniques. © 2016 Society of Chemical Industry.
authors.affiliation: Department of Entomology, University of Minnesota, St Paul, MN, USA.
authors.forename: Joelle F
authors.initials: JF
authors.lastname: Olson
authors.affiliation: Nalco: An Ecolab Company, Naperville, IL, USA.
authors.forename: Leonard M Ver
authors.initials: LM
authors.lastname: Vers
authors.affiliation: Department of Entomology, University of Minnesota, St Paul, MN, USA.
authors.forename: Roger D
authors.initials: RD
authors.lastname: Moon
authors.affiliation: Department of Entomology, University of Minnesota, St Paul, MN, USA.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Kells
mesh_terms: D000447:Aldehydes / Q000494:pharmacology; D000818:Animals; D001511:Bedbugs / Q000737:chemistry* / Q000187:drug effects / Q000502:physiology; D001522:Behavior, Animal / Q000187:drug effects*; D005243:Feces / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D010572:Pest Control, Biological / Q000379:methods; D010675:Pheromones / Q000032:analysis / Q000494:pharmacology; D052617:Solid Phase Microextraction
chemical_list: D000447:Aldehydes; D010675:Pheromones; C057348:2-octenal; C051750:2-hexenal
keywords: Cimex lectularius; aggregation; arrestment; dimethyltrisulfide (DMTS); methyldiethanolamine (MDEA); pheromone