title: Volatile compound diversity and conserved alarm behaviour in Triatoma dimidiata.
abstract: BACKGROUND
  Triatoma dimidiata (Latreille) is a key vector complex of Trypanosoma cruzi, etiologic agent of Chagas disease, as it spans North, Central, and South America. Although morphological and genetic studies clearly indicate existence of at least five clades within the species, there has been no robust or systematic revision, or appropriate nomenclature change for species within the complex. Three of the clades (haplogroups) are distributed in Mexico, and recent evidence attests to dispersal of clades across previously "presumed" monotypic geographic regions. Evidence of niche conservatism among sister species of this complex suggests that geographic dispersal is possible for non-sympatric populations, although no information is available on the behavioural aspects of potential interclade interactions, for instance whether differentiation of chemical signaling or response to these signals could impede communication among the haplogroups.
  
  
  METHODS
  Volatiles emitted by disturbed bugs, Brindley's (BGs), and metasternal (MGs) glands were identified using solid-phase micro-extraction (SPME) and gas chromatography coupled mass spectrometry (GC-MS). Volatile compounds emitted by BGs and MGs, and those secreted by disturbed nymphs and adults, of the three Mexican T. dimidiata haplogroups were tested for avoidance behaviour by conspecific nymphs and adults using an olfactometer.
  
  
  RESULTS
  Triatoma dimidiata haplogroups all have three age-related alarm responses: absence of response by early stage nymphs, stage-specific response by 4-5th stage nymphs, and a shared 4-5th nymph and adult response to adult compounds. Disturbed bugs released 15 to 24 compounds depending on the haplogroup, among which were three pyrazines, the first report of these organoleptics in Triatominae. Isobutyric acid from BGs was the most abundant molecule in the response in all haplogroups, in addition to 15 (h1) to 21 (h2 and h3) MG compounds. Avoidance behaviour of disturbed bugs and volatiles emitted by BGs were haplogroup specific, while those from the MG were not.
  
  
  CONCLUSIONS
  Discriminant and cluster analysis of BG + MG compounds indicate significant separation among the three haplogroups, while alarm response compounds were similar between h2 and h3, both distinct from h1. This latter haplogroup is ancestral phylogenetically to the other two. Our results suggest that alarm responses are a conserved behaviour in the Triatoma dimidiata complex.
authors: Centro Regional de Investigación en Salud Pública (CRISP), Instituto Nacional de Salud Pública (INSP), Tapachula, Chiapas, México. irving_jmc@hotmail.com.|Departamento de Neuroetología Ecológica, Centro de Investigaciones Científicas y Transferencia de Tecnológica a la Producción (CICyTTP), Diamante, Entre Ríos, Argentina. irving_jmc@hotmail.com.
authors: Irving
authors: I
authors: May-Concha
authors: Grupo de Ecología y Manejo de Artrópodos, El Colegio de la Frontera Sur (ECOSUR), Carretera Antiguo Aeropuerto km 2.5, Tapachula, Chiapas, México. jrojas@ecosur.mx.
authors: Julio C
authors: JC
authors: Rojas
authors: Grupo de Ecología y Manejo de Artrópodos, El Colegio de la Frontera Sur (ECOSUR), Carretera Antiguo Aeropuerto km 2.5, Tapachula, Chiapas, México. lcruz@ecosur.mx.
authors: Leopoldo
authors: L
authors: Cruz-López
authors: Departamento de Ecologia Humana, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav), Mérida, Yucatán, México. ibarra.cerdena@gmail.com.
authors: Carlos N
authors: CN
authors: Ibarra-Cerdeña
authors: Centro Regional de Investigación en Salud Pública (CRISP), Instituto Nacional de Salud Pública (INSP), Tapachula, Chiapas, México. jramsey@insp.mx.
authors: Janine M
authors: JM
authors: Ramsey
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D008401:Gas Chromatography-Mass Spectrometry; D007303:Insect Vectors / Q000737:chemistry / Q000145:classification / Q000502:physiology*; D008800:Mexico; D014224:Triatoma / Q000737:chemistry / Q000145:classification / Q000502:physiology*; D055549:Volatile Organic Compounds / Q000737:chemistry* / Q000378:metabolism
chemical_list: D055549:Volatile Organic Compounds
references: J Insect Physiol. 2011 Jul;57(7):939-44
references: 21524656
references: Med Vet Entomol. 2013 Jun;27(2):165-74
references: 23205718
references: Mem Inst Oswaldo Cruz. 2013 Jun;108(4):395-8
references: 23828007
references: PLoS One. 2013;8(8):e70974
references: 23940678
references: J Vector Ecol. 2013 Dec;38(2):353-60
references: 24581366
references: PLoS Negl Trop Dis. 2014 Oct;8(10):e3266
references: 25356550
references: PLoS Negl Trop Dis. 2009;3(3):e393
references: 19274073
references: Acta Trop. 2009 May-Jun;110(2-3):178-86
references: 19084490
references: J Med Entomol. 2009 May;46(3):572-9
references: 19496429
references: J Chem Ecol. 2009 Aug;35(8):861-70
references: 19685263
references: J Med Entomol. 2009 Sep;46(5):1062-73
references: 19769037
references: J Chem Ecol. 2009 Oct;35(10):1212-21
references: 19902303
references: PLoS Negl Trop Dis. 2010;4(3):e620
references: 20209149
references: BMC Biol. 2010;8:121
references: 20828381
references: Biomedica. 2010 Apr-Jun;30(2):207-14
references: 20890568
references: PLoS One. 2011;6(3):e18156
references: 21479180
references: J Med Entomol. 2011 Mar;48(2):262-71
references: 21485361
references: Mol Phylogenet Evol. 2001 Jan;18(1):136-42
references: 11161750
references: Med Vet Entomol. 2001 Dec;15(4):351-7
references: 11776453
references: J Med Entomol. 2003 Nov;40(6):800-6
references: 14765656
references: J Chem Ecol. 2004 Jul;30(7):1329-47
references: 15503523
references: Med Vet Entomol. 1995 Oct;9(4):403-6
references: 8541592
references: Mem Inst Oswaldo Cruz. 2005 Aug;100(5):477-82
references: 16184224
references: Trop Med Int Health. 2006 Jul;11(7):1092-103
references: 16827710
references: J Chem Ecol. 2006 Sep;32(9):2035-52
references: 16902820
references: Infect Genet Evol. 2007 Mar;7(2):343-52
references: 17097928
references: J Vector Ecol. 2007 Jun;32(1):75-82
references: 17633428
references: J Chem Ecol. 2008 Apr;34(4):523-9
references: 18340486
references: PLoS Negl Trop Dis. 2008;2(5):e233
references: 18461141
references: J Chem Ecol. 2008 Jun;34(6):734-41
references: 18496737
references: Mem Inst Oswaldo Cruz. 2008 Sep;103(6):619-21
references: 18949337