Ecological genetics of Adalia beetles: variability and symbiotic bacteria in european populations of the ten-spot ladybird beetle Adalia decempunctata

Abstract

Background. Adalia decempunctata L. (Coleoptera: Coccinellidae) ten-spot ladybird beetle, widespread morphologically variable Palearctic species.
 Materials and methods. DNA polymorphism and infection with Wolbachia, Spiroplasma and Rickettsia symbiotic bacteria were investigated.
 Results. Eight different haplotypes of the mitochondrial COI gene, seven of which were previously unknown, were found in 92 A. decempunctata individuals from nine European collection places: Prague, Rome, Florence, Hamburg, Paris, Stockholm, Moscow, Feodosia and Yalta. A. decempunctata is less variable in mtDNA compared to A. bipunctata. Symbiotic bacteria Wolbachia and Spiroplasma were not detected. Only Rickettsia infestation was found in A. decempunctata specimens, gathered in Stockholm and Feodosia. Rickettsia from A. decempunctata from Feodosia and Stockholm differ by 0.5% in gltA gene. Rickettsia from A. decempunctata from Feodosia is clustered with Rickettsia from A. bipunctata and Coccinella sp. based on the analysis of the gltA gene.
 Conclusion: Three of the eight mtDNA haplotypes are present in the A. decempunctata gene pool from geographically distant habitats. A small amount of nucleotide substitutions between Rickettsia from A. decempunctata and A. bipunctata suggests a single origin of the symbiont in the ladybirds of the genus Adalia, the results do not exclude subsequent horizontal transfers between individuals of both species.

Hereditary symbionts and mitochondria: distribution in insect populations and quasi-linkage of genetic markers

“…Wolbachia induces cytoplasmic incompatibility in Ae. albopictus (Sinkins et al, 1995;Dobson et al, 2004). Most populations are naturally infected with both strains, suggesting that superinfection is common in the field-collected Ae.…”

The genome sequence of the ten-spot ladybird, Adalia decempunctata (Linnaeus, 1758)

“…A recent study has highlighted that ten-spot ladybirds are not only morphologically variable but that the mitochondrial COI gene is highly variable too, eight different haplotypes were found from a sample of 92 individuals from across Europe ( Shaikevich et al , 2019 ). Different strains of the male-killing Rickettsia bacterium infecting A. bipunctata have been shown to be associated with distinct mitochondrial haplotypes.…”

“…This is perhaps unsurprising since both the bacterium and mitochondria are maternally transmitted ( Jiggins & Tinsley, 2005 ). However, this is yet to be proven for A. decempunctata which seems to have a low prevalence of Rickettsia infection ( Shaikevich et al , 2019 ).…”