title: Superparasitism, immune response and optimum progeny yield in the gregarious parasitoid Palmistichus elaeisis.
abstract: BACKGROUND
  The subsequent deposition of an egg clutch by a female parasitoid into a host already parasitised either by itself or a conspecific (i.e. superparasitism) is a counterintuitive adaptive strategy, particularly considering the female parasitoid's ability to recognise the parasitised hosts. Such a scenario suggests that the adaptive value of superparasitism depends on the number of clutches laid in the same host, with consequences for parasitoid progeny yield. Here, we tested whether such is the case for the gregarious parasitoid Palmistichus elaeisis and explored its underlying basis.
  
  
  RESULTS
  Allowing female parasitoids to lay multiple egg clutches in a single melonworm host pupa, parasitoid progeny and fitness exhibited a peak or optimum at three egg clutches laid per host pupa. In addition, haemocyte count, encapsulation and melanisation decreased with the number of egg clutches laid per host pupa.
  
  
  CONCLUSIONS
  An optimum number of three clutches laid per host pupa was detected for P. elaeisis. As immune response via haemocyte production, encapsulation and melanisation decreased with the number of clutches laid per host, the higher parasitoid yield and fitness observed is the likely consequence of a compromised immune response coupled with an accommodative (i.e. scramble) larval competitive strategy allowing enough resources for optimum balance of parasitoid number and quality produced. © 2017 Society of Chemical Industry.
authors.affiliation: Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
authors.forename: Kleber
authors.initials: K
authors.lastname: de S Pereira
authors.affiliation: Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG, Brazil.|ENTO+ Soluções & Pesquisa, CENTEV-UFV, Viçosa, MG, Brazil.
authors.forename: Nelsa Maria P
authors.initials: NMP
authors.lastname: Guedes
authors.affiliation: Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
authors.forename: José E
authors.initials: JE
authors.lastname: Serrão
authors.affiliation: Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
authors.forename: José C
authors.initials: JC
authors.lastname: Zanuncio
authors.affiliation: Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
authors.forename: Raul Narciso C
authors.initials: RNC
authors.lastname: Guedes
mesh_terms: D000818:Animals; D005260:Female; D006434:Hemocytes / Q000276:immunology; D006790:Host-Parasite Interactions; D006927:Hymenoptera / Q000254:growth & development / Q000502:physiology*; D007814:Larva / Q000254:growth & development / Q000502:physiology; D008297:Male; D009036:Moths / Q000276:immunology* / Q000469:parasitology; D010858:Pigmentation; D011679:Pupa / Q000276:immunology / Q000469:parasitology
keywords: encapsulation; haemocyte; idiobiont parasitoid; immunity; intrinsic parasitoid competition; larval competition