Higher aggression towards closer relatives by soldier larvae in a polyembryonic wasp
Dunn, Johanna; Dunn, Derek W.; Strand, Michael R.; Hardy, Ian C.W.
Derek W. Dunn
Michael R. Strand
IAN HARDY IAN.HARDY@NOTTINGHAM.AC.UK
Associate Professor & Reader in Animalpopulation Biology
In the polyembryonic wasp Copidosoma floridanum, females commonly lay one male and one female egg in a lepidopteran host. Both sexes proliferate clonally within the growing host larva. Distinct larval castes develop from each wasp egg, the majority being ‘reproductives’ plus some ‘soldiers’ which sacrifice reproduction and attack competitors. Maturing mixed sex broods are usually female biased, as expected when intra-brood mating is common. Pre-mating dispersal followed by outbreeding is expected to increase sexual conflict over brood sex ratios and result in greater soldier attack rates. Owing to sexually asymmetric relatedness, intra-brood conflicts are expected to be resolved primarily via female soldier attack. We observed soldier behaviour in vitro to test whether lower intra-brood relatedness (siblings from either within-strain or between-strain crosses were presented) increased inter-sexual aggression by female as well as male soldiers. As found in prior studies, females were more aggressive than males but, contrary to expectations and previous empirical observations, soldiers of both sexes showed more aggression towards more closely related embryos. We speculate that lower intra-brood relatedness indicates maternal outbreeding and may suggest a rarity of mating opportunities for reproductives maturing from the current brood, which may enhance the value of opposite sex brood-mates, or that higher aggression towards relatives may be a side-effect of mechanisms to discriminate heterospecific competitors.
|Journal Article Type||Article|
|Publication Date||May 28, 2014|
|Publisher||Royal Society, The|
|Peer Reviewed||Peer Reviewed|
|APA6 Citation||Dunn, J., Dunn, D. W., Strand, M. R., & Hardy, I. C. (2014). Higher aggression towards closer relatives by soldier larvae in a polyembryonic wasp. Biology Letters, 10(5), https://doi.org/10.1098/rsbl.2014.0229|
|Keywords||Aggression, Relatedness, Polyembryonic wasps|
|Copyright Statement||Copyright information regarding this work can be found at the following address: http://creativecommons.org/licenses/by/4.0|
Dunn Dunn Strand Hardy Higher aggression towards closer relatives in a polyembryonic wasp Biology Letters 2014.pdf
Copyright information regarding this work can be found at the following address: http://creativecommons.org/licenses/by/4.0