TY - JOUR
T1 - Asymmetric reproductive isolation and interference in neriid flies
T2 - The roles of genital morphology and behaviour
AU - Bath, Eleanor
AU - Tatarnic, Nikolai
AU - Bonduriansky, Russell
PY - 2012/12/1
Y1 - 2012/12/1
N2 - The processes underlying reproductive isolation, and the traits involved, are the subject of considerable debate in evolutionary biology. Studying the costly sexual interaction of species in secondary sympatry, a phenomenon known as reproductive interference, can help to shed light on past and present isolating mechanisms, as well as the implications of sympatry for individual fitness. We investigated the roles of two sets of traits, genitalic and behavioural, in reproductive isolation and interference in two species of Australian neriid flies, Telostylinus lineolatus and T. angusticollis. Surprisingly, although these species differ markedly in male but not in female genitalia, we found evidence that genital morphology resulted in asymmetric reproductive isolation: T. lineolatus males could transfer sperm to T. angusticollis females, but T. angusticollis males were unable to transfer sperm to T. lineolatus females. However, neither type of cross produced any viable hybrids. Behavioural responses also contributed asymmetrically to both reproductive isolation and reproductive interference. Males pursued both conspecific and heterospecific females. Females of both species discriminated against heterospecific males, but T. lineolatus females exhibited stronger discrimination than T. angusticollis females. Curiously, T. angusticollis males both fought and attempted to copulate with T. lineolatus males, resulting in reduced mating success for T. angusticollis males with conspecific females. Our findings show that both genitalic and behavioural traits can play important roles in reproductive isolation, but the consequences of interspecific divergence in these traits can be surprisingly complex, resulting in asymmetric effects on many aspects of interspecific interactions.
AB - The processes underlying reproductive isolation, and the traits involved, are the subject of considerable debate in evolutionary biology. Studying the costly sexual interaction of species in secondary sympatry, a phenomenon known as reproductive interference, can help to shed light on past and present isolating mechanisms, as well as the implications of sympatry for individual fitness. We investigated the roles of two sets of traits, genitalic and behavioural, in reproductive isolation and interference in two species of Australian neriid flies, Telostylinus lineolatus and T. angusticollis. Surprisingly, although these species differ markedly in male but not in female genitalia, we found evidence that genital morphology resulted in asymmetric reproductive isolation: T. lineolatus males could transfer sperm to T. angusticollis females, but T. angusticollis males were unable to transfer sperm to T. lineolatus females. However, neither type of cross produced any viable hybrids. Behavioural responses also contributed asymmetrically to both reproductive isolation and reproductive interference. Males pursued both conspecific and heterospecific females. Females of both species discriminated against heterospecific males, but T. lineolatus females exhibited stronger discrimination than T. angusticollis females. Curiously, T. angusticollis males both fought and attempted to copulate with T. lineolatus males, resulting in reduced mating success for T. angusticollis males with conspecific females. Our findings show that both genitalic and behavioural traits can play important roles in reproductive isolation, but the consequences of interspecific divergence in these traits can be surprisingly complex, resulting in asymmetric effects on many aspects of interspecific interactions.
KW - Combat
KW - Genitalia
KW - Hybridization
KW - Mating behaviour
KW - Neriidae
KW - Reproductive interference
KW - Reproductive isolation
KW - Sexual competition
KW - Telostylinus angusticollis
KW - Telostylinus lineolatus
UR - http://www.scopus.com/inward/record.url?scp=84870475668&partnerID=8YFLogxK
U2 - 10.1016/j.anbehav.2012.08.025
DO - 10.1016/j.anbehav.2012.08.025
M3 - Article
AN - SCOPUS:84870475668
SN - 0003-3472
VL - 84
SP - 1331
EP - 1339
JO - Animal Behaviour
JF - Animal Behaviour
IS - 6
ER -