Project properties

Title Genetic and environmental influence on color in ladybird beetles
Group Entomology, Laboratory of
Project type thesis
Credits 36
Supervisor(s) Dr. P.W. de Jong
Examiner(s) Prof. M. Dicke
Contact info peter.dejong@wur.nl
Begin date 2015/09/30
End date 2020/12/31
Description Ladybird beetles are often brightly colored, likely mainly to advertise their untasteful or even toxic properties to potential predators. Across and within species, color patterns vary wildly. Especially the exotic ladybird beetle Harmonia axyridis, the �multicolored Asian ladybird�, displays an extreme amount of color variation. It is known that this color variation is partly influenced by genetic variation; some forms are predominantly red with black spots, whereas others are mostly black, with red spots, and these basic patterns are governed by various alleles at a locus. Within these color forms, different extent of melanisation (causing the black color on the elytra) exists. Here it is known that this variation in melanisation is heavily influenced by environmental factors (an example of phenotypic plasticity). However, for another species, the two-spot ladybird beetle, also genetic variation was present for spot-size. The question is: is there also genetic variation for spot-size/extent of melanisation in Harmonia axyridis, and how much of the observed variation in melanisation is caused by such genetic variation, and how much by the environment? This is an interesting question, since the color of the ladybirds does not only advertise unpalatability to predators, but is likely adaptive in other aspects, such as thermoregulation. Genetic variation for melanisation means that selection can selection can lead to differences in occurrence of different intensities of melanisation at different localities or times. This work will involve a lot of ladybird breeding under controlled conditions, and a lot of measuring of extent of melanisation, for example with the imaging software �Image-J�. The project can be started at any time of the year.
Used skills captive breeding
Requirements For doing a BSc-thesis at Entomology, there are no requirements for specific courses.
For doing a MSc-thesis or internship at Entomology, the following requirements apply: ENT-30806 + a second ENT-course (preferably ENT-30306 or ENT-50806 or ENT-53806). As an alternative for the second ENT-course, PHP-30806 or BHE-30306 can be selected.
Note: these requirements do not apply for MBI students; MBI students should check the requirements for doing an ENT MSc-thesis or internship in the study programme of their specialisation.