Consequently, farmers apply more pesticides in an attempt to manage pest outbreaks, which can increase the potential for insecticide resistance to develop. When populations of insect pests grow increasingly resistant to pesticide applications, the rate of pesticide application also increases – driving a cycle of growing reliance on chemical applications in managed systems. Additionally, excessive use of fertilizers also contributes to the increase in insect populations by enhancing plant growth and vigor as well as the nutritional qualities of plant tissue that insects feed upon (Lu et al., 2007).
Changing climates = changing insect communities. The challenges of pest management in monoculture systems are compounded by a changing climate. Warmer temperatures have been demonstrated to increase the fecundity and metabolism of insect pests, resulting in elevated pest pressure in cropping systems, which increases insecticide applications (Deutsch et al., 2018).
Increasing temperatures can also extend the geographical distribution of many insect pests northwards and into higher altitudes (Liebhold & Bentz, 2011). Finally, milder winters are likely to increase the survival of overwintering pests since they will be exposed to fewer frosts or cold snaps during that time.
While it may be difficult to prevent or reverse the effects on climate change on modern agriculture, there are some practices that growers may adopt to mitigate some of the unique challenges it presents. This includes adopting more efficient irrigation practices, diversifying crop rotations, and changing management and infrastructure to suit new and expected conditions (Janowiak et al., 2016).
Insects provide benefits. Insect-mediated pollination is an essential component of most cultivated crops and over 80% of all wild, flowering plant species. Pollinators, including bees, butterflies, and even some flies and beetles, require a variety of nectar, pollen, and nesting resources to survive. When monocultures serve as the dominant landscape across swathes of the United States, it prevents pollinators from accessing the diversity and duration of bloom that most pollinators need to thrive.
In addition, insects can boost crop production through the natural biological control of pests by insect predators and parasitoids. However, in simplified landscapes, many predators and parasitoids lack the right conditions (such as places to hide, mate, or spend the winter) to survive over many generations.
We can provide improved support for insect pollinator, predators and parasitoids by planting or maintaining natural and semi-natural habitats, such as forests and meadows, along managed field margins, or by planting diverse floral resources between rows in agricultural production systems.
What to do?
No one can deny that increasing crop yields is vital to having sufficient and affordable food available to feed an increasing human population; nevertheless, it must be recognized that current practices may not be supportive or sustainable in the years to come.
Government subsidies or regulation can be one way to encourage the transformation of monocultures into more sustainable farming systems that are rich in crop diversity and stabilize ecological systems. However, without such support, there are many effective and low-input practices that can be considered. Introducing crop rotation in perennial cover crops, interchanging chemical-based insecticides with organic products, implementing precision agriculture approaches to spot-treat specific crop zones that need fertilizers and pesticide applications as needed, and planting mixture of wild plants in borders or streps to provide resources for beneficial insects are some of the practices that farmers can implement on their farms to improve the ecosystem balance of their crops.
Source : psu.edu