My research investigated whether (i) symbiotic yeasts isolated from the digestive tract of social wasps, (ii) commercial yeasts, or (iii) the volatiles these yeasts produce can be used as trap baits for capturing yellowjackets. I found that adding brewer’s yeast to dried fruit and fruit powder enhanced attraction of yellowjackets in Argentina. I also found that the two yeast species Hanseniaspora uvarum and Lachancea thermotolerans, isolated from North American yellowjackets and grown on grape juice-infused agar, attract yellowjackets. Lachancea thermotolerans in admixture with fruit powder was also attractive and expressed an additive effect when combined with a commercial wasp lure. Synthetic analog blends of the volatiles produced by H. uvarum growing on grape juice-infused media and L. thermotolerans growing on fruit powder were both attractive to western yellowjackets, but not to other yellowjackets. In summary, symbiotic yeasts and their semiochemicals, respectively, show potential as yellowjacket trap baits or lures
