Native and non-native plant species differentially affect arthropod community dynamics with consequences for crop production in Lower Rio Grande Valley
In agricultural ecosystems, arthropods play critical roles- including biocontrol, pollination services, and as herbivores. While herbivory negatively affects crop production, the recent decline in beneficial insect numbers have created a global concern, and consequently have led into multiple lines of conservation strategies. Agroecological practices that can provide sustenance, nesting, and refuge for beneficial organisms are considered as some of them, except we lack a better understanding of how seasonal and crop specific variation can affect their community dynamics. In this study, we examined this by investigating how native and non-native plants, when incorporated into a vegetable agroecosystem in Lower Rio Grande Valley in south Texas can influence arthropod community over their life cycle. We used a combination of different trapping systems and the following species: four species native to Texas: Ratibidia columnifera, Helianthus anuus L., Desmanthus virgatus var. and Pappophorum bicolor. We then compared these results to the non-native species Lobularia maritima (L.) Desv. We found that among the arthropods trapped, pests accounted for 66.3%, and were significantly more prevalent than beneficials. More specifically, we found that sampling time and feeding guild, also affected arthropods, but not plant species or their native/ invasive status. Detailed analyses also revealed that Eulophidae was the most abundant parasitoids family, and Aleyrodidae was the most abundant herbivore family. We followed the experiment by also examining whether these differences had any consequences for eggplant, the cash crop planted post cover, although we found no significant effects. Collectively, we show that arthropod community response to vegetation is variable, and a single species may not create the interactive dynamics to meet the benefits desired in food production and needs to be examined further
