Ecological Interactions Between Native and Non-Native Lady Beetle Species.

Lady beetles (family Coccinellidae) are found worldwide, with 90% of the almost 6000 species acting as agriculturally beneficial predators. Lady beetles are an important biological pest control, commonly consuming aphids, and are also used as a bioindicator species due to their sensitivity to climatic and trophic changes. As an important agricultural resource and a piece of our ecosystem’s diversity, the interactions between native and non-native species warrant further research. In order to observe these native and non-native lady beetle species interactions, we ran two types of trials with a total of five species: competition and consumption. In the competition trials, we placed the lady beetles in a native/non-native species combination along with three aphids, and recorded their behaviors and weight change over the course of an hour. In the consumption trials, we placed the lady beetles with an aphid infested plant in a native/non-native species combination, and calculated their consumption rates over 24 hours. We also created an iNaturalist page to aid in our understanding of species distributions and seasonality. The preliminary results demonstrate that Harmonia axyridis, a non-native species, is a stronger competitor than the native species tested. From further analyzing our data, we hope to see whether there is potential for coexistence, for which intraspecific competition must measure higher than interspecific competition. Further research should be conducted to include more than two species per trial, as lady beetles are often found co-existing with multiple other species.