Disclosed herein are combinations of Yersinia entomophaga and/or Yersinia nurmii and/or toxins therefrom, with one or more of a variety of substances, including animal repellents, acaracides, antimicrobials, avicides, bactericides, biostimulants, disinfectants and/or sanitizers, fungicides, gastropodicides, herbicides, insecticides, insect growth regulators, insect repellents, miticides, molluscicides, nematicides, plant signal molecules, plant nutrients, plant fertilizers, predacides, piscicides, rodenticides, termiticides, viricides, and the like. The combinations may have additive effects or unexpected effects on pests, insects being one example, and/or on plant growth and/or plant yield. Also disclosed are methods for using the disclosed combinations.