title: The value of an egg: resource reallocation in ladybirds (Coleoptera: Coccinellidae) infected with male-killing bacteria.
abstract: Male-killing bacteria are thought to persist in host populations by vertical transmission and conferring direct and/or indirect fitness benefits to their hosts. Here, we test the role of indirect fitness benefits accrued from resource reallocation in species that engage in sibling egg cannibalism. We found that a single-egg meal significantly increased larval survival in 12 ladybird species, but the value of an egg (to survival) differed substantially between species. Next, we tested the impact of three male-killing bacteria on larval survival in one ladybird species, Adalia bipunctata. Spiroplasma reduced larval survival, whereas Wolbachia and Rickettsia had no effect. However, Spiroplasma-infected larvae showed the greatest response to a single-egg meal. The indirect fitness benefit obtained from a single egg is thus so large that even male-killing bacteria with direct fitness costs can persist in host populations. This study supports the hypothesis that fitness compensation via resource reallocation can explain male-killing bacteria persistence.
authors: Department of Genetics, University of Cambridge, Cambridge, UK.
authors: S
authors: S
authors: Elnagdy
authors: M E N
authors: ME
authors: Majerus
authors: L-J Lawson
authors: LJ
authors: Handley
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000382:microbiology*; D005260:Female; D007814:Larva / Q000382:microbiology / Q000502:physiology; D008297:Male; D010063:Ovum; D012281:Rickettsia / Q000502:physiology; D012737:Sex Factors; D013045:Species Specificity; D013149:Spiroplasma / Q000502:physiology; D020577:Wolbachia / Q000502:physiology