Identification and evaluation of semiochemicals for the biological control of the beetle Omorgus suberosus (F.) (Coleoptera: Trogidae), a facultative predator of eggs of the sea turtle Lepidochelys olivacea (Eschscholtz)

PLoS One. 2017 Feb 13;12(2):e0172015. doi: 10.1371/journal.pone.0172015. eCollection 2017.

Abstract

The beetle Omorgus suberosus (F.) is a facultative predator of eggs of the olive ridley turtle Lepidochelys olivacea (Eschscholtz). Laboratory and field investigations were conducted in order to characterize volatile attractants of O. suberosus and to explore the potential for application of these volatiles in a selective mass trapping method. Headspace sorptive extraction (HSSE) coupled to thermo-desorption gas chromatography-mass spectrometry (TD-GC-MS) analysis of the volatile constituents from beetles or turtle nests revealed 24 potential compounds. However, electroantennographic (EAG) measurements revealed antennal sensitivity only to indole, linoleic acid, trimethylamine, dimethyl sulphide, dimethyl disulphide and ammonia. Behavioural tests showed that these compounds are highly attractive to O. suberosus. Field trapping experiments revealed that indole and ammonia were more attractive than the other volatile compounds and showed similar attractiveness to that produced by conventional baits (chicken feathers). The use of a combined bait of indole and NH3 would therefore be the most effective trap design. The data presented are the first to demonstrate effective massive capture of O. suberosus using an attractant-based trapping method. These findings have potential for the development of an efficient mass trapping method for control of this beetle as part of efforts towards conservation of L. olivacea at La Escobilla in Oaxaca, Mexico.

MeSH terms

  • Ammonia / analysis
  • Ammonia / isolation & purification
  • Animals
  • Coleoptera / physiology*
  • Conservation of Natural Resources / methods
  • Eggs*
  • Feeding Behavior / physiology*
  • Female
  • Gas Chromatography-Mass Spectrometry / methods
  • Geography
  • Indoles / analysis
  • Indoles / isolation & purification
  • Insect Control / methods
  • Male
  • Mexico
  • Nesting Behavior
  • Pheromones / analysis*
  • Pheromones / isolation & purification
  • Turtles / physiology*
  • Volatile Organic Compounds / analysis
  • Volatile Organic Compounds / isolation & purification

Substances

  • Indoles
  • Pheromones
  • Volatile Organic Compounds
  • Ammonia
  • indole

Grants and funding

The study was funded by the Programa de Conservación de Especies en Riesgo (PROCER) and the Dirección de Especies Prioritarias para la Conservación of the National Commission of Natural Protected Areas (CONANP) to GH. We are also grateful to INECOL A.C. for financial support awarded to GH. This research was fully funded by the National Commission for Protected Natural Areas (CONANP–Mexico). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.