Lovely Ladybirds!

Understanding the genetic basis of adaptation is a fundamental aim in evolutionary biology. Ladybirds are colourful and popular insects, as well as economically important biological control agents. This talk will discuss research into factors controlling ladybird colour-pattern, survival and reproduction, These factors impact on ladybird use for biocontrol and have broad ecological significance.

The importance of the microbiota associated with invertebrate hosts is increasingly being recognised. The majority of these organisms are not readily grown in lab cultures and such techniques therefore fail to provide useful levels of detail regarding the presence and function of such microorganisms. Fundamental questions about the host-parasite or commensal basis of these relationships are simply unstudied in many cases. We have studied the effect of one group of ladybird endosymbionts, known as male-killers. These maternally inherited bacteria kill male hosts, and hence have a large reproductive cost to a female ladybird. Some ladybirds have evolved resistance to these bacteria. Ladybirds are also host to other endosymbionts, the effects of which are unknown. We have investigated symbionts present in Harmonia axyridis and Halyzia sedecimguttata, two ladybird species with contrasting ecologies.

Ladybird colour-patterns influence their survival and reproduction. Bright, contrasting colours serve as warning colours that the ladybirds may be toxic or distasteful to predators. Colour-patterns can also be important in determining ladybird mate choice. Breeding experiments in the 2- and 10-spot ladybirds, Adalia bipunctata and A. decempunctata, show that the variation in their colour-patterns is controlled by one gene. RAD (Restriction-site Associated DNA)-sequencing has been used to identify markers linked to colour-pattern. This has allowed construction of a linkage map around the gene controlling colour-pattern in both species. In addition breeding data of the crosses involved has provided information about other genetic and evolutionary factors important in ladybird ecology.

The seminar will be hosted using Zoom. A Google calendar invite featuring the Zoom link will be sent to Biology staff and students before the seminar date. For all enquiries please contact Biology DMT Hub.