Parasite key to harlequin ladybird success
Researchers in Germany have discovered what may be the secret of success for the invasive harlequin ladybird (Harmonia axyridis) that allows it to outcompete indigenous ladybird species. H axyridis originates in Asia and has been used as a biological control agent against aphids, thrips and scale insects in the US. The researchers found that H axyridis acts as a vector for an obligate parasitic microsporidium closely related to Nosema thompsoni. That is lethal for the native seven-spot ladybird (Coccinella septempunctata). Infections are acquired when C septempunctata feeds on microsporidia-contaminated H axyridis eggs or larvae. Details of the study have been published in the journal, Science.