title: Effects of laboratory colonization on Bactrocera dorsalis (Diptera, Tephritidae) mating behaviour: 'what a difference a year makes'.
abstract: Laboratory-reared insects are widely known to have significantly reduced genetic diversity in comparison to wild populations; however, subtle behavioural changes between laboratory-adapted and wild or 'wildish' (i.e., within one or very few generations of field collected material) populations are less well understood. Quantifying alterations in behaviour, particularly sexual, in laboratory-adapted insects is important for mass-reared insects for use in pest management strategies, especially those that have a sterile insect technique component. We report subtle changes in sexual behaviour between 'wildish' Bactrocera dorsalis flies (F1 and F2) from central and southern Thailand and the same colonies 12 months later when at six generations from wild. Mating compatibility tests were undertaken under standardised semi-natural conditions, with number of homo/heterotypic couples and mating location in field cages analysed via compatibility indices. Central and southern populations of Bactrocera dorsalis displayed positive assortative mating in the 2010 trials but mated randomly in the 2011 trials. 'Wildish' southern Thailand males mated significantly earlier than central Thailand males in 2010; this difference was considerably reduced in 2011, yet homotypic couples from southern Thailand still formed significantly earlier than all other couple combinations. There was no significant difference in couple location in 2010; however, couple location significantly differed among pair types in 2011 with those involving southern Thailand females occurring significantly more often on the tree relative to those with central Thailand females. Relative participation also changed with time, with more southern Thailand females forming couples relative to central Thailand females in 2010; this difference was considerably decreased by 2011. These results reveal how subtle changes in sexual behaviour, as driven by laboratory rearing conditions, may significantly influence mating behaviour between laboratory-adapted and recently colonised tephritid fruit flies over a relatively short period of time.
authors.affiliation: School of Earth, Environmental and Biological Sciences, Queensland University of Technology, Brisbane 4001 Queensland, Australia.
authors.forename: Mark K
authors.initials: MK
authors.lastname: Schutze
authors.affiliation: Insect Pest Control Laboratory, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria.
authors.forename: Thilak
authors.initials: T
authors.lastname: Dammalage
authors.affiliation: NSW Department of Primary Industries, Locked Bag 26, Gosford NSW 2250, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Jessup
authors.affiliation: Insect Pest Control Laboratory, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria.
authors.forename: Marc J B
authors.initials: MJ
authors.lastname: Vreysen
authors.affiliation: NSW Department of Primary Industries, Locked Bag 26, Gosford NSW 2250, Australia.
authors.forename: Viwat
authors.initials: V
authors.lastname: Wornoayporn
authors.affiliation: School of Earth, Environmental and Biological Sciences, Queensland University of Technology, Brisbane 4001 Queensland, Australia.
authors.forename: Anthony R
authors.initials: AR
authors.lastname: Clarke
keywords: Oriental fruit fly; isolation indices; laboratory adaptation; sexual compatibility