Intraguild predation on the whitefly parasitoid Eretmocerus eremicus by the generalist predator Geocoris punctipes: a behavioral approach

PLoS One. 2013 Nov 19;8(11):e80679. doi: 10.1371/journal.pone.0080679. eCollection 2013.

Abstract

Intraguild predation (IGP) takes place when natural enemies that use similar resources attack each other. The impact of IGP on biological control can be significant if the survival of natural enemy species is disrupted. In the present study, we assessed whether Geocoris punctipes (Hemiptera: Lygaeidae) engages in IGP on Eretmocerus eremicus (Hymenoptera: Aphelinidae) while developing on whitefly nymphs of Trialeurodes vaporariorum (Hemiptera: Aleyrodidae). In choice and non-choice tests, we exposed G. punctipes to parasitized and non-parasitized whitefly nymphs. We found that G. punctipes does practice IGP on E. eremicus. However, choice tests assessing G. punctipes consumption revealed a significant preference for non-parasitized T. vaporariorum nymphs. Subsequently, we investigated whether E. eremicus females modify their foraging behavior when exposed to conditions involving IGP risk. To assess this, we analyzed wasp foraging behavior under the following treatments: i) whitefly nymphs only (control = C), ii) whitefly nymphs previously exposed to a predator ( = PEP) and, iii) whitefly nymphs and presence of a predator ( = PP). In non-choice tests we found that E. eremicus did not significantly modify its number of attacks, attack duration, oviposition duration, or behavior sequences. However, E. eremicus oviposited significantly more eggs in the PEP treatment. In the PP treatment, G. punctipes also preyed upon adult E. eremicus wasps, significantly reducing their number of ovipositions and residence time. When the wasps were studied under choice tests, in which they were exposed simultaneously to all three treatments, the number of attacks and frequency of selection were similar under all treatments. These results indicate that under IGP risk, E. eremicus maintains several behavioral traits, but can also increase its number of ovipositions in the presence of IG-predator cues. We discuss these findings in the context of population dynamics and biological control.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Female
  • Hemiptera / parasitology
  • Hemiptera / physiology*
  • Nymph / parasitology
  • Predatory Behavior*
  • Wasps / physiology*

Grants and funding

Financial support is acknowledged to Mexican Council for Science and Technology (CONACyT, Ciencia Básica program, Project ID: 0157259) granted to RR-R. ‘KOPPERT México SA de CV’ and ‘Organismos Benéficos para la Agricultura SA de CV’ are acknowledged for partial financial support on the acquisition of wasps and predators. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.