Weeds Enhance Insect Diversity and Abundance and May Improve Soil Conditions in Mango Cultivation of South Florida

Simple Summary When weeds are left in mango farms, especially native wildflowers, there is a potential they may provide pollen and nectar to increase beneficial insect abundance and diversity. We examined how weed presence affects insects on mango trees as well as soil health. We found that weeds significantly increased pollinating and parasitoid (natural pest control agents) insect abundance and diversity. There was no difference in predatory insects between treatments, and slightly more herbivorous insects on weedy mango trees. Pollinators in mango flowers and spiders were also greater on weedy mango trees. Soil conditions were significantly improved in soil carbon and pH by the presence of weeds. These results show that a tolerable level of weed species may benefit insect, plant, and soil biodiversity in farms which oftentimes have very little life on them. This study examined if weeds could serve as insectary plants to increase beneficial insect abundance and diversity in mango cultivation in southern Florida. Additionally, we examined how weed presence affects mango tree soil health. We found that weeds significantly increased pollinating and parasitoid insect abundance and diversity. Eight insect orders and eighteen families were significantly more abundant on mango trees with weeds growing beneath them than those where weeds were removed. There was no difference in predatory insects between treatments, and slightly more herbivorous insects on weedy mango trees. Pollinating insects visiting mango flowers in the weed treatment were significantly greater, as well as spiders on weedy mango trees. However, there were more lacewings (Neuroptera) observed on the mango trees without weeds, and leaf chlorophyll in the old and new mango leaves was significantly greater, in the weed-free treatment. Soil conditions, however, significantly improved in soil carbon and a greater pH reduction in the presence of weeds, though weeds affected neither soil nitrogen, phosphorous, nor chlorophyll in productive green leaves. These results show that a tolerable level of selective weed species' presence may benefit insect, plant, and soil biodiversity in farms. This is important in increasing production, sustainability, and biodiversity in agriculture, which otherwise may be deficient in non-crop life.

Automated summary

When weeds are present in mango farms, they can provide pollen and nectar, increasing the abundance and diversity of beneficial insects. This study found that weeds significantly increased the abundance and diversity of pollinators and natural pest control agents on mango trees. Additionally, soil conditions were improved with the presence of weeds. These results highlight the importance of tolerating a certain level of weed species for the biodiversity and sustainability of agricultural ecosystems.