Environmental Consequences of Invasive Species: Greenhouse Gas Emissions of Insecticide Use and the Role of Biological Control in Reducing Emissions

Abstract

Greenhouse gas emissions associated with pesticide applications against invasive species constitute an environmental cost of species invasions that has remained largely unrecognized. Here we calculate greenhouse gas emissions associated with the invasion of an agricultural pest from Asia to North America. The soybean aphid, Aphis glycines, was first discovered in North America in 2000, and has led to a substantial increase in insecticide use in soybeans. We estimate that the manufacture, transport, and application of insecticides against soybean aphid results in approximately 10.6 kg of carbon dioxide (CO2) equivalent greenhouse gasses being emitted per hectare of soybeans treated. Given the acreage sprayed, this has led to annual emissions of between 6 and 40 million kg of CO2 equivalent greenhouse gasses in the United States since the invasion of soybean aphid, depending on pest population size. Emissions would be higher were it not for the development of a threshold aphid density below which farmers are advised not to spray. Without a threshold, farmers tend to spray preemptively and the threshold allows farmers to take advantage of naturally occurring biological control of the soybean aphid, which can be substantial. We find that adoption of the soybean aphid economic threshold can lead to emission reductions of approximately 300 million kg of CO2 equivalent greenhouse gases per year in the United States. Previous studies have documented that biological control agents such as lady beetles are capable of suppressing aphid densities below this threshold in over half of the soybean acreage in the U.S. Given the acreages involved this suggests that biological control results in annual emission reductions of over 200 million kg of CO2 equivalents. These analyses show how interactions between invasive species and organisms that suppress them can interact to affect greenhouse gas emissions.

Reduced-Risk Pest Management Programs for Eastern U.S. Peach Orchards: Effects on Arthropod Predators, Parasitoids, and Select Pests

“…Whereas reduced-risk programs provide pest control comparable with that of conventional programs, they signiÞcantly reduce concerns about human health and safety, but are more expensive to implement on average (Agnello et al 2009). Reducing the number of pesticide applications can also lower greenhouse gas emissions associated with manufacturing, delivery, and application of pesticides (Heimpel et al 2013). To date, ecological considerationsÑspeciÞcally, effects on a wide range of nontarget beneÞcial arthropodsÑ have not been fully assessed in more realistic Þeld and long-term conditions.…”

A global synthesis of the effects of biological invasions on greenhouse gas emissions

“…Nevertheless, invasions can also indirectly affect GHGs by engaging human activities to control the spread and impacts of invasive species, which has remained largely unrecognized. One recent example revealed that GHG emissions associated with application of pesticides to control invasive Aphis glycines in US agricultural systems can be substantial (Heimpel et al, 2013). Such indirect ways of altering GHGs through human management of invasive species are critical and deserve future attention.…”

Biological control using invertebrates and microorganisms: plenty of new opportunities

“…In some cases low residue levels give farmers a preferred partnership with retailers who prefer to buy products with less residues. Furthermore, biological control might contribute to considerable reduction in emission of greenhouse gasses in comparison with pesticide use (Heimpel et al 2013).…”