title: Mate-searching behaviour of common and rare wasps and the implications for pollen movement of the sexually deceptive orchids they pollinate.
abstract: Pollinator behaviour directly affects patterns of pollen movement and outcrossing rates in plants. In orchids pollinated by sexual deception of insects, patterns of pollen movement are primarily determined by the mate-searching behaviour of the deceived males. Here, using a capture-mark-recapture study (CMR) and dietary analysis, we compare mate-searching behaviour in relation to local abundance of two pollinator species and explore the implications for pollen movement in sexually deceptive Drakaea (Orchidaceae). Drakaea are pollinated solely by the sexual deception of male thynnine wasps. The rare Drakaea elastica and widespread D. livida occur sympatrically and are pollinated by the rare but locally common Zaspilothynnus gilesi, and the widespread and abundant Z. nigripes, respectively. Local abundance was significantly different with Z. nigripes twice as abundant as Z. gilesi. For the 653 marked wasps, there was no significant difference in median movement distance between Z. gilesi and Z. nigripes. However, the maximum movement distance was twice as high for Z. gilesi (556 m) compared with Z. nigripes (267 m). This is up to three times greater than previously reported for thynnines in CMR studies. Recapture rates were six times higher in Z. gilesi (57%) compared to Z. nigripes (9%). Pollen loads and wasp longevity were similar, suggesting that this difference in recapture rate arises due to differences in the number of males moving at a scale >500 m rather than through diet or mortality. Differences in the frequency of longer movements may arise due to variation in the spatial distribution of the wingless females. We predict that pollen movement will largely be restricted to within populations of Drakaea (<500 m), with few movements between populations (>500 m).
authors.affiliation: Kings Park and Botanic Garden, The Botanic Gardens and Parks Authority, Perth, Western Australia, Australia. myles.menz@bgpa.wa.gov.au
authors.forename: Myles H M
authors.initials: MH
authors.lastname: Menz
authors.forename: Ryan D
authors.initials: RD
authors.lastname: Phillips
authors.forename: Kingsley W
authors.initials: KW
authors.lastname: Dixon
authors.forename: Rod
authors.initials: R
authors.lastname: Peakall
authors.forename: Raphael K
authors.initials: RK
authors.lastname: Didham
mesh_terms: D000818:Animals; D001070:Appetitive Behavior; D003433:Crosses, Genetic; D005260:Female; D035264:Flowers; D008297:Male; D052586:Mating Preference, Animal; D029595:Orchidaceae / Q000235:genetics*; D054817:Pollination; D012724:Sex Attractants; D012726:Sexual Behavior, Animal; D014863:Wasps / Q000502:physiology*
chemical_list: D012724:Sex Attractants
references.citation: Am Nat. 2010 Nov;176(5):E143-51
references.pmid: 20843263
references.citation: Science. 2003 Oct 17;302(5644):437-8
references.pmid: 14564006
references.citation: Trends Plant Sci. 2011 Jan;16(1):4-12
references.pmid: 20980193
references.citation: Biol Rev Camb Philos Soc. 2005 Aug;80(3):413-43
references.pmid: 16094807
references.citation: Proc Biol Sci. 2012 Dec 7;279(1748):4786-94
references.pmid: 23055065
references.citation: Evolution. 1996 Dec;50(6):2207-2220
references.pmid: 28565662
references.citation: Biol Rev Camb Philos Soc. 2011 Feb;86(1):33-75
references.pmid: 20377574
references.citation: Proc Natl Acad Sci U S A. 2008 Sep 9;105(36):13456-61
references.pmid: 18768793
references.citation: PLoS One. 2011;6(5):e19997
references.pmid: 21603569
references.citation: Bioinformatics. 2012 Oct 1;28(19):2537-9
references.pmid: 22820204
references.citation: Mol Phylogenet Evol. 2011 Apr;59(1):195-205
references.pmid: 21310250
references.citation: Science. 2009 Jul 31;325(5940):571-3
references.pmid: 19644110
references.citation: Theor Popul Biol. 1978 Feb;13(1):72-98
references.pmid: 644520
references.citation: Am Nat. 1998 Jun;151(6):487-96
references.pmid: 18811371
references.citation: PLoS One. 2010 May 26;5(5):e10738
references.pmid: 20520813
references.citation: PLoS One. 2012;7(11):e45973
references.pmid: 23209547