|MadSci Network: Zoology|
Your enquiry brings up the usual bug problem. Most people assume the bug is an insect so I'll start from there.I am guessing clothes moths are your reference point, although all moths are well-known for their sense of smell.
The bay leaf contains three insect "influencers":
1. Eugenol is a likely constituent that can repel and even kill insects. It was found that weevils died more quickly than other beetles, but I've found no data on moths.
2. Lauric acid is a solid white powder used instead of sprays as an organic insecticide. However is is also toxic to fish and amphibians in high concentration, so its large-scale use could be restictive for those who don't want to harm the aquatic environment
3. Myrcene seems the least effective of the aromatic compounds found in bay.Found in many perfumes, it rarely stops insects from hanging around women's necks! It repels insects in some cases but is found in so many plants that they don't mind it much.It does seem to work on mosquito larvae which helps the anti-malaria campaign. Being less poisonous than lauric acid, it could probably be used safely in water.
So in that brief survey, experiments have proved that parts of Bay's chemistry puts off various beetles and moths and flies, depending on whether they are adapted in their life style to certain plants that contain them.Whichever bugs you want could probably be safely restrained with the whole bay leaf. You could use one of the constituents for a really organic insecticidal result.
Try the links in the MadSci Library for more information on Zoology.